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DESIGN AND DEVELOPMENT OF OCEAN
MONITORING SYSTEM BASED ON GPS
ANUAR BIN MOHD SALLEH
UNIVERSITI TUN HUSSEIN ONN MALAYSIA
DESIGN AND DEVELOPMENT OF OCEAN MONITORING SYSTEM
BASED ON GPS
ANUAR BIN MOHD SALLEH
A thesis submitted in
fulfillment of the requirements for award of the
Doctor of Philosophy
Faculty of Civil and Environmental Engineering
Universiti Tun Hussein Onn Malaysia
FEBRUARY 2017
iii
DEDICATION
For my beloved familyhellip
iv
ACKNOWLEDGEMENT
First of all I am much more thankful of ALLAH SWT for the special blessing over
me I would like to illustrate my heartfelt gratefulness to all those who have
contributed in completing this study
I would like to thank Universiti Tun Hussein Onn Malaysia and Ministry of
Higher Education (MOHE) Malaysia for offering me financial support and for giving
me the opportunity to carry out this study
In particular I am thankful to my supervisor Sr Dr Mohd Effendi bin Daud
for his trust on me And I am also thankful for his social technical encouragement
guidance and recommendations
The most important acknowledgement goes to my parents and family for the
emotional support and blessing during my study
Last but not least I am thankful to my friends for their positive attitude
support and encouragement
v
ABSTRACT
Coastal zone of Malaysia has a vital role in socio-economic and environmental in
pursuing the country development However it constantly faces a threat from coastal
erosion The report year 2013 from the Department of Irrigation and Drainage
Malaysia showed 29 of Malaysian coastal has been experiencing erosion at various
levels and primarily driven by ocean waves Hence this study focused on
developing the ocean monitoring system consists of a buoy with Global Positioning
System (GPS) technology reference station and data analysis techniques The buoy
was developed by considering local factors and improves the performance of existing
buoy Comparison with existing GPS buoy has found that the GPS buoy is far
exceeded in term of physical specifications costs sensors sensitivity and observation
interval Based on the verification with slider machine this system has been able to
provide high accuracy result less than 05 cm compared to the standard value of
slider machine The RMS error from data analysis technique is less than 00016 m
Validation with Department of Survey and Mapping Malaysia (JUPEM) automatic
tide gauges have found both methods agreed on tidal pattern with small discrepancy
of less than 10 cm Encouraging results were also obtained when the observations off
coast Senggarang compared with manual observations historical data and Malaysia
Meteorological Department (MetMalaysia) wave forecasting This system has been
observing the same tidal patterns with data analysis RMS error less than 00013 m
Comparison with the height of historical wave data and wave forecast shows the
results of observations of this system are in the range of comparisons made
Difference of 20 mm was obtained when compared with the wave height observed
manually The usefulness of GPS buoy data also has been demonstrated in analyzing
the monsoon wind influences at off coast Senggarang
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
DESIGN AND DEVELOPMENT OF OCEAN MONITORING SYSTEM
BASED ON GPS
ANUAR BIN MOHD SALLEH
A thesis submitted in
fulfillment of the requirements for award of the
Doctor of Philosophy
Faculty of Civil and Environmental Engineering
Universiti Tun Hussein Onn Malaysia
FEBRUARY 2017
iii
DEDICATION
For my beloved familyhellip
iv
ACKNOWLEDGEMENT
First of all I am much more thankful of ALLAH SWT for the special blessing over
me I would like to illustrate my heartfelt gratefulness to all those who have
contributed in completing this study
I would like to thank Universiti Tun Hussein Onn Malaysia and Ministry of
Higher Education (MOHE) Malaysia for offering me financial support and for giving
me the opportunity to carry out this study
In particular I am thankful to my supervisor Sr Dr Mohd Effendi bin Daud
for his trust on me And I am also thankful for his social technical encouragement
guidance and recommendations
The most important acknowledgement goes to my parents and family for the
emotional support and blessing during my study
Last but not least I am thankful to my friends for their positive attitude
support and encouragement
v
ABSTRACT
Coastal zone of Malaysia has a vital role in socio-economic and environmental in
pursuing the country development However it constantly faces a threat from coastal
erosion The report year 2013 from the Department of Irrigation and Drainage
Malaysia showed 29 of Malaysian coastal has been experiencing erosion at various
levels and primarily driven by ocean waves Hence this study focused on
developing the ocean monitoring system consists of a buoy with Global Positioning
System (GPS) technology reference station and data analysis techniques The buoy
was developed by considering local factors and improves the performance of existing
buoy Comparison with existing GPS buoy has found that the GPS buoy is far
exceeded in term of physical specifications costs sensors sensitivity and observation
interval Based on the verification with slider machine this system has been able to
provide high accuracy result less than 05 cm compared to the standard value of
slider machine The RMS error from data analysis technique is less than 00016 m
Validation with Department of Survey and Mapping Malaysia (JUPEM) automatic
tide gauges have found both methods agreed on tidal pattern with small discrepancy
of less than 10 cm Encouraging results were also obtained when the observations off
coast Senggarang compared with manual observations historical data and Malaysia
Meteorological Department (MetMalaysia) wave forecasting This system has been
observing the same tidal patterns with data analysis RMS error less than 00013 m
Comparison with the height of historical wave data and wave forecast shows the
results of observations of this system are in the range of comparisons made
Difference of 20 mm was obtained when compared with the wave height observed
manually The usefulness of GPS buoy data also has been demonstrated in analyzing
the monsoon wind influences at off coast Senggarang
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
iii
DEDICATION
For my beloved familyhellip
iv
ACKNOWLEDGEMENT
First of all I am much more thankful of ALLAH SWT for the special blessing over
me I would like to illustrate my heartfelt gratefulness to all those who have
contributed in completing this study
I would like to thank Universiti Tun Hussein Onn Malaysia and Ministry of
Higher Education (MOHE) Malaysia for offering me financial support and for giving
me the opportunity to carry out this study
In particular I am thankful to my supervisor Sr Dr Mohd Effendi bin Daud
for his trust on me And I am also thankful for his social technical encouragement
guidance and recommendations
The most important acknowledgement goes to my parents and family for the
emotional support and blessing during my study
Last but not least I am thankful to my friends for their positive attitude
support and encouragement
v
ABSTRACT
Coastal zone of Malaysia has a vital role in socio-economic and environmental in
pursuing the country development However it constantly faces a threat from coastal
erosion The report year 2013 from the Department of Irrigation and Drainage
Malaysia showed 29 of Malaysian coastal has been experiencing erosion at various
levels and primarily driven by ocean waves Hence this study focused on
developing the ocean monitoring system consists of a buoy with Global Positioning
System (GPS) technology reference station and data analysis techniques The buoy
was developed by considering local factors and improves the performance of existing
buoy Comparison with existing GPS buoy has found that the GPS buoy is far
exceeded in term of physical specifications costs sensors sensitivity and observation
interval Based on the verification with slider machine this system has been able to
provide high accuracy result less than 05 cm compared to the standard value of
slider machine The RMS error from data analysis technique is less than 00016 m
Validation with Department of Survey and Mapping Malaysia (JUPEM) automatic
tide gauges have found both methods agreed on tidal pattern with small discrepancy
of less than 10 cm Encouraging results were also obtained when the observations off
coast Senggarang compared with manual observations historical data and Malaysia
Meteorological Department (MetMalaysia) wave forecasting This system has been
observing the same tidal patterns with data analysis RMS error less than 00013 m
Comparison with the height of historical wave data and wave forecast shows the
results of observations of this system are in the range of comparisons made
Difference of 20 mm was obtained when compared with the wave height observed
manually The usefulness of GPS buoy data also has been demonstrated in analyzing
the monsoon wind influences at off coast Senggarang
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
iv
ACKNOWLEDGEMENT
First of all I am much more thankful of ALLAH SWT for the special blessing over
me I would like to illustrate my heartfelt gratefulness to all those who have
contributed in completing this study
I would like to thank Universiti Tun Hussein Onn Malaysia and Ministry of
Higher Education (MOHE) Malaysia for offering me financial support and for giving
me the opportunity to carry out this study
In particular I am thankful to my supervisor Sr Dr Mohd Effendi bin Daud
for his trust on me And I am also thankful for his social technical encouragement
guidance and recommendations
The most important acknowledgement goes to my parents and family for the
emotional support and blessing during my study
Last but not least I am thankful to my friends for their positive attitude
support and encouragement
v
ABSTRACT
Coastal zone of Malaysia has a vital role in socio-economic and environmental in
pursuing the country development However it constantly faces a threat from coastal
erosion The report year 2013 from the Department of Irrigation and Drainage
Malaysia showed 29 of Malaysian coastal has been experiencing erosion at various
levels and primarily driven by ocean waves Hence this study focused on
developing the ocean monitoring system consists of a buoy with Global Positioning
System (GPS) technology reference station and data analysis techniques The buoy
was developed by considering local factors and improves the performance of existing
buoy Comparison with existing GPS buoy has found that the GPS buoy is far
exceeded in term of physical specifications costs sensors sensitivity and observation
interval Based on the verification with slider machine this system has been able to
provide high accuracy result less than 05 cm compared to the standard value of
slider machine The RMS error from data analysis technique is less than 00016 m
Validation with Department of Survey and Mapping Malaysia (JUPEM) automatic
tide gauges have found both methods agreed on tidal pattern with small discrepancy
of less than 10 cm Encouraging results were also obtained when the observations off
coast Senggarang compared with manual observations historical data and Malaysia
Meteorological Department (MetMalaysia) wave forecasting This system has been
observing the same tidal patterns with data analysis RMS error less than 00013 m
Comparison with the height of historical wave data and wave forecast shows the
results of observations of this system are in the range of comparisons made
Difference of 20 mm was obtained when compared with the wave height observed
manually The usefulness of GPS buoy data also has been demonstrated in analyzing
the monsoon wind influences at off coast Senggarang
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
v
ABSTRACT
Coastal zone of Malaysia has a vital role in socio-economic and environmental in
pursuing the country development However it constantly faces a threat from coastal
erosion The report year 2013 from the Department of Irrigation and Drainage
Malaysia showed 29 of Malaysian coastal has been experiencing erosion at various
levels and primarily driven by ocean waves Hence this study focused on
developing the ocean monitoring system consists of a buoy with Global Positioning
System (GPS) technology reference station and data analysis techniques The buoy
was developed by considering local factors and improves the performance of existing
buoy Comparison with existing GPS buoy has found that the GPS buoy is far
exceeded in term of physical specifications costs sensors sensitivity and observation
interval Based on the verification with slider machine this system has been able to
provide high accuracy result less than 05 cm compared to the standard value of
slider machine The RMS error from data analysis technique is less than 00016 m
Validation with Department of Survey and Mapping Malaysia (JUPEM) automatic
tide gauges have found both methods agreed on tidal pattern with small discrepancy
of less than 10 cm Encouraging results were also obtained when the observations off
coast Senggarang compared with manual observations historical data and Malaysia
Meteorological Department (MetMalaysia) wave forecasting This system has been
observing the same tidal patterns with data analysis RMS error less than 00013 m
Comparison with the height of historical wave data and wave forecast shows the
results of observations of this system are in the range of comparisons made
Difference of 20 mm was obtained when compared with the wave height observed
manually The usefulness of GPS buoy data also has been demonstrated in analyzing
the monsoon wind influences at off coast Senggarang
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
vi
ABSTRAK
Persisir pantai Malaysia memainkan peranan yang penting pembangunan Negara
samada dalam bidang sosio-ekonomi atau alam sekitar Walau bagaimanapun ia
sentiasa menghadapi ancaman daripada hakisan pantai Laporan tahun 2013
daripada Jabatan Perparitan dan Saliran Malaysia menyatakan 29 daripada persisir
pantai Malaysia telah mengalami hakisan pada berbagai peringkat yang berpunca
daripada ombak laut Oleh itu kajian ini memberi tumpuan kepada pembangunan
sistem cerapan lautan yang terdiri daripada boya yang dilengkapi sistem
penentududukan sejagat (GPS) stesen rujukan dan teknik analisa data Perbandingan
dengan boya GPS sediada mendapati boya ini jauh lebih baik dari segi fizikal kos
sensitiviti penderia dan sela cerapan Berdasarkan verifikasi dengan mesin gelangsar
sistem ini telah dapat memberikan hasil yang berketepatan tinggi iaitu kurang
daripada 05 cm berbanding nilai piawai mesin gelangsar Nilai RMS untuk teknik
analisa data adalah kurang daripada 00016 m Validasi dengan tolok pasang surut
automatik Jabatan Ukur dan Pemetaan Malaysia (JUPEM) mendapati kedua-dua
kaedah memberikan corak pasang surut yang sama dengan perbezaan yang kecil
kurang daripada 10 cm Hasil yang memberangsangkan turut diperolehi apabila
cerapan di luar persisir pantai Senggarang dibandingkan dengan cerapan secara
manual data arkib dan ramalan ombak Jabatan Meteorologi Malaysia
(MetMalaysia) Sistem ini telah mencerap corak pasang surut yang sama dengan nilai
RMS teknik analisa data kurang daripada 00013 m Perbandingan ketinggian ombak
dengan data arkib dan ramalan ombak mendapati hasil cerapan sistem ini berada
dalam lingkungan perbandingan yang dibuat Ketepatan yang tinggi iaitu 20 mm
telah diperolehi apabila perbandingan dengan cerapan ketinggian ombak secara
manual dibuat Kegunaan data boya GPS turut ditunjukkan dalam analisis pengaruh
angin monsun terhadap kekuatan ombak di persisir pantai Senggarang
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
vii
TABLE OF CONTENTS
TITLE i
DECLARATION ii
DEDICATION PAGE iii
ACKNOWLEDGEMENT iv
ABSTRACT v
CONTENTS vii
LIST OF TABLES xii
LIST OF FIGURES xiii
LIST OF SYMBOLS AND ABBREVIATIONS xviii
LIST OF APPENDICES xix
CHAPTER 1 INTRODUCTION
11 Background 1
12 Problem statement 3
13 Aim and objectives 6
14 Scope of study 6
15 Significance of study 8
16 Organization of thesis 9
CHAPTER 2 LITERATURE REVIEW
21 Introduction 10
22 Ocean wave 11
221 Wind generate ocean wave 12
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
viii
222 Tidal wave 14
2221 Tides characteristic 14
2222 Tidal flow 15
223 Wave characteristics 16
224 Wave energy 17
225 Spectral analysis 18
23 Global Navigation Satellite System (GNSS) 19
231 Global Positioning System 20
232 GPS signals 21
233 Errors in GPS observations 22
234 GPS segment 23
2341 Space segment 23
2342 Control segment 24
2343 User segment 25
235 GPS measurement 25
236 GPS observation techniques 26
2361 Real Time Kinematic (RTK) 27
2362 Post-Processing Kinematic (PPK) 28
237 GPS buoy data processing 28
238 Double difference analysis by Bernese GPS
software 30
2381 Data transfer and copy into the campaign
folder 30
2382 Import data into Bernese format using
sub program RXOBV3 31
2383 Prepare Earth orientation and orbit
information 31
2384 Data processing 33
2385 Make a first network solution 35
2386 Resolve ambiguities using sub program
GPSEST 36
2387 Final network solution using sub program
GPSEST 36
239 Filtering 36
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
ix
24 Water level measurement 37
25 Wave buoy 41
251 Implementation of GPS technology in wave
buoys application 48
26 Comparison of GPS buoy and tide gauge data 55
261 Geoid concept 55
262 Ellipsoid concept 56
263 Geoid height model 57
27 Summary 58
CHAPTER 3 METHODOLOGY
31 Introduction 59
32 Literature review and support data 59
33 Buoy development 61
331 Reviewing and design the buoys 62
3311 Pole for GPS receiver 63
3212 Buoy body 65
3213 Ballast 67
332 Buoy fabrication 68
3321 Material selection 69
3322 Shaping the buoy body 71
3323 Field test 76
3324 Anti rust process 77
3325 Buoy power supply 80
333 Development of mooring line 81
3331 Damping line 82
3332 Mono rope 83
3333 Anchor 83
34 Reference station development 84
341 Location of reference station 85
342 Designing the tower for reference station 87
343 Material for reference station 88
344 Fabrication of reference station 88
345 Installation of reference station 90
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
x
35 Fieldwork campaign 92
351 Establishment of reference station 93
352 Verification of the equipment and data analysis
techniques 96
3521 Slider machine 97
3522 Slider machine field observation 99
353 Validation of observation data 103
3531 Measuring of geoid and ellipsoid
separation value 106
354 Wave observation 108
36 GPS data processing 110
361 Data processing using static methods 112
362 Data processing using kinematic methods 114
37 Data editing 116
38 Height transformation 117
39 Wave height 117
310 Data filtering 118
311 Wave energy 119
312 Summary 119
CHAPTER 4 RESULT AND ANALYSIS
41 Introduction 121
42 Development of buoy and reference station 121
43 Establishment of FKAAS reference station 124
44 Verification of the equipment and data analysis
techniques 125
45 Validation of observation data 128
46 Wave observation at Off Coast Senggarang 133
461 Wave processing analysis 133
462 Wave accuracy 135
4621 Tidal type 135
4622 Tide observation 138
4623 Wave height analysis 145
47 Summary 151
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xi
CHAPTER 5 WAVE STRENGTH ANALYSIS OFF COAST SENGGARANG
51 Introduction 154
52 Power Spectra Density 154
521 PSD analysis during each monsoon 155
522 Influence of different monsoon to wave
strength 158
523 Wave strength analysis of northeast monsoon
from different year 160
53 Summary 161
CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS
61 Introduction 162
62 Conclusions 163
621 Design fabricate and test the ocean monitoring
system 166
622 Verify the data analysis technique 166
623 Validate the GPS buoy measurement 166
624 Accuracy assessment of GPS buoy data 166
625 PSD analysis 166
63 Recommendations for future research 166
REFERENCES 167
APPENDIX 181
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xii
LIST OF TABLES
21 Detail specification of wave buoy 42
31 Breakdown of the wave height percentage in the Straits of Malacca
from 2010 to 2012 61
32 Detail specification of slider machine 99
33 Summary of output file from final solution processing step 114
34 Summary of output file from final solution processing step 116
41 Summary of ocean monitoring system development 123
42 Comparison of the GPS buoy that has been developed with GPS buoy
available in the market 124
43 Coordinate of FKAAS reference station 125
44 Result of data processing from slider machine field observation 126
45 Summary of output file from final solution processing step 129
46 RMS error for each data processing 134
47 Comparison of manual (leveling staf) and GPS buoy wave height
observation 150
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xiii
LIST OF FIGURES
21 Wind generate the waves (adopted from Florida Center for
Instructional Technology 2005) 13
22 Types of tides and tidal phases (adopted from National
Oceanic and Atmospheric Administration 2013) 15
23 Basic characteristics of wave (adopted from Sorensen 2006) 17
24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006) 20
25 Segments of the GPS system (adopted from Snider 2016) 23
26 Processing steps for double difference analysis by Bernese GPS
software 31
27 (a) Filter kernel and sample image (b) Image result after filtering
(adopted from McDonnell 1981) 37
28 Water level measurement using leveling staff 38
29 Illustration of automatic tide gauge (adopted from National
Data Buoy Center 2010) 39
210 Pressure gauge sensor is one of sensor integrated in this equipment
(adopted from Sontek 2015) 40
211 (a) Datawell waverider buoy during sea observation (b) plan of the
Datawell buoy series DWR-MK III (adopted from Datawell 2014) 44
212 (a) Triaxys directional wave buoy during sea observation (b) parts
of the buoy (adopted from Triaxys 2014) 45
213 (a) Fugro Seawatch Wind Lidar (b) mooring system of
Seawatch buoy (adopted from Fugro 2012) 46
214 (a) Envirtech MKI-4 for deployed for tsunami detection (b) design
of the buoy (adopted from Envirtech 2015) 47
215 Wave heights of moored-sea GPS buoy after filtering (adopted
from Joodaki et al 2013) 49
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xiv
216 (a) Wave height result for GPS buoy by kinematic DGPS
(b) Wave height result for GPS buoy by kinematic PPP with IGS
rapid orbit (adopted from Chen et al 2004) 51
217 Observed during the most energetic wave event on 14 Jun 2010
with a moored Datawell DWR-G7 buoy (black lines with circles)
and a GlobalSat GPS (blue lines with asterisks) position receiver
mounted on the same buoy (adopted from Herbers et al 2012) 53
218 The summary of related study 54
219 Relationship between topography geoid and ellipsoid (adopted from
JUPEM 2005) 58
31 Methodology flow chart 60
32 Buoy development process 62
33 Basic principle of designing the buoy shape 63
34 Pole for GPS receiver placed on upper part of buoy (mm[inch]) 64
35 Buoy body was designed based on conical shape (mm[inch]) 66
36 Plan view of (a) buoy and (b) buoy cover (mm[inch]) 67
37 Plan of buoy ballast (mm[inch]) 68
38 Steel sheets has been selected as a material for buoy body 70
39 Sheet bending machine used to bend the steel sheet 71
310 Welding and fabrication during buoy development process 72
311 (a) buoy body parts were completely welded (b) windows for solar
panel 72
312 (a) brackets for solar panel (b) solar panel installed 73
313 (a) applying silicon glue on the buoy and rubber sheets (b) acrylic
glued to rubber sheets with silicon glue (c) steel frame screwed
through all the sheets and tight to the buoy body 74
314 (a) grove on base cover (b) rubber lsquoOrsquo ring (c) install the rubber lsquoOrsquo
ring in grove (d) putting the cover on buoy 75
315 (a) buoy fitted with float (b) GPS antenna pole (c) ballast 75
316 Performing the buoy field test 77
317 The process of hot dip galvanizing (adopted from Wire Mesh
Machine 2014) 78
318 Hot dip galvanizing kettle (adopted from Wire Mesh Machine 2014) 79
319 The galvanized buoy passed the quality control checked 80
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xv
320 (a) buoy in heavy duty undercoat primer (b) painted buoy to
safeguard the buoy against corrosion 80
321 GPS buoy power supply (a) 12 volt battery (b) solar panel
(c) solar charger controller (d) volt meter 81
322 Damping line components (a) d shackle dan swivel (b) float and
rubber cord (c) complete damping line 82
323 Type of rope used as a buoy mooring line (a) mono rope (b) stainless
steel wire rope 83
324 Two unit of anchor was used to ensure that the GPS buoy anchored
at the same location throughout the observation 84
325 The surrounding of FKAAS south tower 85
326 Structures on top of FKAAS south tower 87
327 Stairway and excess to FKAAS south tower roof top 89
328 (a) wooden mould box (b) concrete poured in the mould (c) putting
the reinforce steel in the concrete 89
329 Fabrication of main pillar and supporting legs 90
330 Pulley chain used to lift the concrete block to the roof 91
331 Installation of reference station (a) fitted main pillar on the concrete
block (b) adjusted the supporting legs (c) concreting the concrete
block to the floor 92
332 (a) supporting leg (b) main pillar (c) reference station 92
333 (a) FKAAS building complex (b) FKAAS south tower 94
334 Location of FKAAS reference station and IGS reference station
(NTUS-01) 95
335 (a) receiver and controller of Leica GS15 (b) direct power supply
connector 95
336 (a) GPS antenna screwed to the antenna pole (b) antenna pole
screwed to the main pole (c) antenna pole mark is aligned with
main pole mark 96
337 (a) designing the slider machine (b) electric motors used to move
the conveyer belt (c) GPS antenna mounted on the slider machine 98
338 GPS antenna driven back and forth using slider machine 98
339 Location of reference station and locations of field observation 100
340 The first location for slider machine field work observations
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xvi
located near FKAAS 101
341 The second location for slider machine field work observations
located infront of Ayer Hitam Fire Station building 102
342 The third location for slider machine field work observations
located in front of Modern Agriculture Ayer Hitam building 103
343 JUPEM national tidal gauge telemetry station 103
344 Location of JUPEM national tidal gauge telemetry stations
bench mark reference station and GPS buoy location 105
345 (a) small pick-up to transport the buoy (b) small boat used to deploy
the buoy (c) final preparation before the buoy deploy 105
346 GPS buoy has been deployed at observation location 106
347 Static GPS observation on JUPEM bench mark J5318 108
348 (a) buoy transported by boat to the location of the observations
(b) buoy deployed at the observation location (c) waves height
were measured manually using the level staff 109
349 Fieldwork location off coast Senggarang Batu Pahat Johor 110
350 GPS data processing by static method using Bernese 50 software 113
351 GPS data processing by kinematic method using Bernese 50 software 115
352 Wave height definition (adopted from CDIP 2015) 118
41 Wave height from slider machine observed at three different locations 127
42 Calculation of geoid ellipsoid separation value (adopted from
CDIP 2015) 130
43 Tide observed by GPS buoy on 3 June 2014 at Kukup pier 131
44 Tide on 362014 observed by GPS buoy and automatic tide gauge 132
45 Tide observed by GPS buoy on 17 February 2014 at off coast
Senggarang 136
46 Tide observed by GPS buoy on 14 October 2014 at off coast
Senggarang 137
47 Tide observed by GPS buoy on 9 June 2015 at off coast Senggarang 138
48 Combination of unfiltered and filtered tidal data on 17 February
2014 at off coast Senggarang 139
49 Tide observed by both method on 17 February 2014 at off coast
Senggarang 140
410 Combination of unfiltered and filtered tidal data on 14 October
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xvii
2014 at off coast Senggarang 141
411 Tide observed by both method on 14 October 2014 at off coast
Senggarang 142
412 Combination of unfiltered and filtered tidal data on 9 June 2015
at off coast Senggarang 143
413 Tide observed by both method on 9 June 2015 at off coast Senggarang 144
414 Part of highest wave height observed by GPS buoy on 9 June 2015 146
415 Part of lowest wave height observed by GPS buoy on 17 February 2015 147
416 Maximum wave height on 9 June 2015 predicted by WAM 148
417 Levelling staff used to measure the water surface level 149
418 Tide observed by GPS buoy on 11 February 2015 at off coast
Senggarang 151
51 PSD analysis during northeast monsoon 156
52 PSD analysis during inter monsoon 157
53 PSD analysis during southwest monsoon 158
54 Comparison of PSD analysis during three different monsoon 159
55 Comparison of PSD analysis during northeast monsoon from
two different years 161
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xviii
LIST OF SYMBOLS AND ABBREVIATIONS
AWAC - Acoustic Wave and Current
MDBP - Majlis Daerah Batu Pahat
MMD - Malaysian Meteorological Department
DID - Department of Irrigation and Drainage
NAHRIM - National Hydraulic Research Institute of Malaysia
DSMM - Department of Survey and Mapping Malaysia
UTHM - Universiti Tun Hussein Onn Malaysia
FKAAS - Fakulti Kejuruteraan Awam dan Alam Sekitar
L - Wave length (horizontal distance between two peaks or in any
other point on the waves to the same point in the next wave)
H - Wave height (vertical distance from the trough to the crest of
same wave)
Η - Amplitude (H 2)
G or g - Acceleration of gravity
D - Water depth from sea bottom
T - Wave period (time for a wave length measured from peak to
peak)
F - Frequency (1T number of waves that passes a given point per
second)
ρ - Density of water (gcm-3)
E - Energy measured in joule per square meter (Jm-2)
V - Volume
B - Bouyancy
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xix
LIST OF APPENDICES
APPENDIX TITLE PAGE
A1 Malaysian Meteorological Department oceanographic data 181
A2a Detail drawing of buoy design 183
A2b Detail drawing of buoy design 184
A3 Malaysian Meteorological Department oceanographic data 185
A4 Plan view of buoy 186
A5 Detail drawing of mooring line 187
A6 Detail drawing of mooring line 188
A7 Detail drawing of reference station tower 189
A8 Technical specification of Leica GS15 190
A9 Procedures of equipment setting 192
A10 Output of GPSEST processing (final network solution) 196
A11 Output of GPSEST processing (final network solution) 205
B1 Output of GPSEST processing (FKAAS reference station) 213
B2 Output of GPSEST processing (location 1) 214
B3 Output of GPSEST processing (location 2) 216
B4 Output of GPSEST processing (location 3) 218
B5 Output of GPSEST processing (final network solution) 220
B6 Output of GPSEST processing (static observation) 222
B7 Output of GPSEST processing (first observation) 224
B8 Output of GPSEST processing (second observation) 226
B9 Output of GPSEST processing (third observation) 228
B10 Malaysian Meteorological Department oceanographic data 230
B11 WAM wave forecast on 30 October 2015 231
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
xx
B12 WAM wave forecast on June 2015 232
B13 WAM wave forecast on 24 October 2015 233
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
CHAPTER 1
INTRODUCTION
11 Background
Ocean is one of the earthrsquos complex physical characteristics yet fully understood by
man The wave tide and wind are dominant natural external forces in the ocean A
lot of study related to wave tide and wind has been done to help understand its
characteristics which are advantages for human beings Accurate forecasts of all
these forces are of the utmost importance for the individuals who live work or travel
on or near the oceans (Pinardi and Woods 2002) The best decision in the economics
or engineering can be made when the sufficient information has been obtained The
coastal engineering is one of the example of the necessity for prediction of wave
Also observation data of wave and tide has given useful information to the
monitoring of the rise in the sea level caused by the global warming and mitigation
programs for the damaged natural resources
Ocean has a great influence on Malaysia because most of this country has
been surrounded by the ocean with a total of 4675 kilometres of coastline whereby
the Peninsular Malaysia has 2068 kilometres and East Malaysia has 2607 kilometres
of coastline The South China Sea separate two distinct parts of Malaysia from each
other The western part of Peninsular Malaysia is also facing the Strait of Malacca
The coastal zone of Malaysia has a special socio-economic and environmental
significance More than 70 of the population lives within the coastal area and a lot
of economic activities such as urbanization agriculture recreation and eco-tourism
fisheries aquaculture and oil and gas exploration are situated in the area Within
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
2
these coastal areas the industrialization and development demands had a great
influence on the resources and coastline itself with a large percentage of population
living within 5 km from these areas The zoning plans with multiple usages exist
only in the framework of concrete management ie the coastal and marine protected
areas (Agardy 1993) Generally the coastal zone plays a vital role in the
development of the country however it constantly faces a threat from erosion
The National Coast Erosion Study which began in 1984 and completed by
1986 was the first comprehensive study carried out to assess the shoreline of
Malaysia It has been reported by the study that 52 of the coastline in the east coast
of Peninsular Malaysia is being eroded 43 is stable 1 is rebuilding and 4
undergoes changes according to the seasons In the west coast 50 of the coastline
is being eroded 30 is stable and 20 is rebuilding (Ghazali 2006) An eroding
coastline is considered critical if the structures within the area are in immediate
danger whilst it is deemed significant if the erosion is going to endanger the
structures within the five years without any coastal protection An eroding shoreline
is deemed acceptable if the backshore area is uninhabited The economic value of the
development of backshore area and the physical rate of erosion are considered as the
primary factors to determine the category of shoreline The latest study has revealed
that about 29 of the total of 4800 km of Malaysian shoreline was subjected to the
varying degree of erosion (Department of Irrigation and Drainage Malaysia 2013)
Coastal erosion is a natural phenomenon which results from the interactions
between natural process and the system The natural process is primarily responsible
for coastal erosion and it is driven by waves (Inch 2014) Although erosion is
mainly contributed by waves action our knowledge on this factor is still far from
sufficient This occurs because of the shortage of data coverage is not
comprehensive and observation techniques are not efficient
In most of the countries it has been observed that the most appropriate
coastal and shoreline data in Malaysia are currently collected by many government
departments private sector organization scientists and consultants Moreover except
for the data regarding tidal elevation and shore-based wind data on other important
parameters such as waves and currents are hardly collected if available the
collection programme is tailored to a specific with a short term duration (Bernatchez
and Dubois 2008)
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
3
Because the availability of ocean tidal and wave height data for Malaysian
ocean is not comprehensive new effort to collect wave data must be made Tidal
data can only be obtained in certain places if there is Department of Survey and
Mapping Malaysia (JUPEM) tidal observation stations located While the wave
height data supplied by Malaysian Meteorological Department (MET) was obtained
from volunteering ship observations that sail through our waters Since it is from the
commercial ship data is less comprehensive because normal for commercial ships to
choose a same route and will only change the route in case of bad weather
Ocean wave measurement from satellite combined with global wave and
atmospheric numerical models are dramatically changing our way of obtaining ocean
wave data for engineering purposes Remote sensing satellite observations are now at
the point of providing reliable global long-term wave statistics A direct sea state
observation is straightforward however the usual observations from ships in the
transit are not adequate enough to provide the reliable data (Campbell and Wynne
2011)
Although the remote sensing satellite is capable of providing imagery for the
wave characteristics extraction process however it is not an absolute solution for the
measurement of ocean waves This remote sensing satellite is still restricted and
fixed to its repetition orbit As a solution the satellite of Global Positioning System
(GPS) provides an ultimate solution due to its numerous numbers which contributes
to the flexible observation and unlimited coverage (Kaplan and Hegarathy 2005)
The GPS satellite has been used for wave observation globally by many researchers
such as Yang and Lo (2000) Chang and Sun (2004) Harigae et al (2005) Daud et
al (2008) and Cui and Kouguchi (2011) Hence this study will be focusing on GPS
wave buoy system development
12 Problem statement
Ocean wave data in Malaysia are currently collected by many government agencies
private sector organization scientists and consultants The government agencies are
Malaysian Meteorological Department Department of Survey and Mapping
Malaysia Royal Navy Malaysia Department of Irrigation and Drainage (DID) and
Marine Department Malaysia Although there are many parties involve the wave
data are still insufficient because the present observations do not cover all Malaysian
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
4
water subject to observations by third parties and conventional observation methods
used (Yaakob et al 2004)
Problem of data coverage is due to the type of equipment used The
equipment used is categorized as fix type equipment makes the process of relocation
to the area of interest is impossible to do Although the equipment is capable of
providing a high accuracy data but it covers only a particular area where the
equipment is installed An example is the JUPEM automatic tide gauge This
equipment has been installed in 22 national tidal gauge telemetry stations throughout
Malaysia (JUPEM 2016) Tidal data to all these areas is available but other areas
like Batu Pahat where there is no observation stations nearby alternative method for
wave observation should be considered to address this issue Users also do not get
the high accuracy data For example the JUPEM tidal data that can be obtained only
in hourly intervals Moreover data on other important parameters such as waves and
currents are hardly collected if available the collection programme is tailored to a
specific with a short term duration (Bernatchez and Dubois 2008)
Data collection also depends on the observations by third parties examples
are waves data which was provided by MET The wave data were observed by
voluntary commercial ship that sailed through the water of this country This data
only covers the water around the shipping lane at a certain period of time Users are
unable to request for wave data for certain area and time Given these data obtained
from voluntary commercial ship the accuracy is also questionable
Methods of data observation using conventional equipment also contributed
to this problem The conventional observation of the wave or tide is performed by
using the fixed type observation equipment which was equipped with water pressure
sensor ultrasonic sensor or accelerometer (Nagai et al 2005) This sensors are very
sensitive and require delicate handling In order to get high accuracy data it needs
periodical calibration and maintenance which involves high costs In addition this
equipment is also difficult to be relocated to other locations
Researchers have taken actions to overcome this issue through their personal
wave observation Muzathik et al (2011) has deployed an Acoustic Wave and
Current (AWAC) device to observe the characteristics of waves along the
Terengganu coast Although the equipment managed to observe the wave
characteristics of waves but it requires carefully checking and validation of the
instrument to ensure the accuracy of the collected data Validation and maintainance
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
5
of this equipment is very costly In addition this equipment is difficult to install and
need highly skilled individuals The equipment is considered as a fix type equipment
and relocation process is difficult
Taira et al (1996) used the electromagnetic current meter and acoustic
sensors to observe oceanographic data off the Kuala Terengganu coast Although the
equipment is capable of observing the relevant data it requires a large ship for
deployment The periodic calibration is a must as the equipment have sensitive
sensors Although the equipment is categorized as transferable but the process is
costly
Marghany (2000) had used ERS-l and AIRSARTOPSAR data to extract
wave spectra to predict the alterations in shoreline on the basis of wave refraction
and sediment transport Although this technique can be used to extract the wave
spectra for modelling of the alterations in shoreline but still the assistance is required
for verification from other data sources such as ship observation ground truth data
and aerial photography Any imperfection of supporting data will influenced the
generated waves data Since this method still requires other supporting data before
the waves information is obtained makes it not a practical solution
Methods that have been mentioned before is not a comprehensive solution to
the problem of wave observation in Malaysia Practical solutions which able to meet
the needs of many parties and suitable to the countrys waters condition must be
produced to address this issue Presently the GPS technology provides the best
solution to overcome this problem The new buoy type observation equipment
adapting GPS technology has excellent features of sea level and wave propagation
measurement systems as proposed by different researchers around the world such as
Doong et al (2011) Waseda et al (2014) Cheng et al (2008) and Collins et al
(2014) It is capable of providing the function that the fluctuation of sea surface of a
broad frequency band can be observed in the accuracy of several centimeter
continuously (Dawidowicz 2014) The principles functions and accuracy of the
system are also reported by Joodaki et al (2013) Nagai et al (2003) Terada et al
(2003) Ohta et al (2006) and Daud et al (2008)
Hence this study focuses on developing an ocean monitoring system
consisting of a buoy equiped with high precision GPS receiver high precision
reference station and data analysis techniques which is suitable for the Malaysian
coastal area especially for the Straits of Malacca
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
6
13 Aim and objectives
To overcome the short comings of the wave observation in Malaysia and its lack of
data coverage its accuracy and out-dated techniques therefore the aim of this study
is to develop an ocean monitoring system which utilises the GPS technology
To achieve these aim the specific objectives of this research are
i) To design fabricate and test the stability of the ocean monitoring system
ii) To verify the data analysis technique and validate the GPS buoy measurement
iii) To analyze the effect of tidal wave and monsoon wind on wave energy
14 Scope of the study
The scopes of this study can be divided and described in the following aspects
i) Study area
The area of study chosen is the coastal of Senggarang Batu Pahat Johor The
area is selected because it has experienced severe erosion where the
destruction of property coastal areas and agricultural areas have occurred
(Utusan Malaysia 2012) Further it is a high populated and rapid
development area Aim of this study is to develop GPS buoy to measure high
accuracy tidal and wave height data for this area Hopefully the data provided
able to help the responsible authorities to understand the wave characteristics
and solve the erosion problems within this area
ii) Strait of Malacca wind and wave historical data
The Strait of Malacca wind and wave historical data from 2010 to 2012 has
been obtained from Malaysian Meteorological Department The analysis from
this data is one of the critical inputs which should be necessarily considered
during the designing process of the GPS buoy
iii) Wave simulator (slider machine)
The slider machine is capable of replicating the movement of buoy constantly
for a long period This machine is very helpful in verification validation and
understanding process throughout this study The GPS antenna was put on the
slider machine and it constantly keeps on rotating during the observation The
observation data were compared with the standard data to verify and validate
the data analysis techniques and equipment of this study
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
7
iv) GPS buoy
The designing of GPS buoy has been performed by considering the wind
wave historical data buoy buoyancy roll and heave factors weight and water
proofing The fabrication process and choosing the most appropriate material
were carefully done to ensure the lasting usage and cheap
v) Reference station
The reference station is very important in the observations of GPS as it is the
point of reference to all the fieldwork campaign in this study A data of high
accuracy can be obtained only if the reference station is stable and capable of
receiving the GPS satellite signals of high quality
vi) Wave observation
The wave observation was performed four times during three different
monsoons This observation was continuous for 30 hours with data logging
rate of 1 Hz During the GPS buoy observation the manual observation of
wave height and tidal were also done for the purpose of data comparison
vii) Tidal data
The tidal data of JUPEM was used to validate the tidal data observed by
using the GPS buoy The JUPEM data is reliable because this department is
responsible of providing the entire tidal data in Malaysia for public and
private usage It was collected by automatic fix tide gauge at several locations
in the whole Malaysia
viii) Data analysis techniques and programming
Development of data analysis techniques and programming was done by
using Bernese 50 and MATLAB software
15 Significance of study
This study is of significant importance because of its major contribution to several
parties such as local authorities government agencies and private sectors
Furthermore it also provides low cost effective and precise solution to measure the
wave characteristics The government agencies such as Malaysian Meteorological
Department Department of Irrigation and Drainage (DID) and National Hydraulic
Research Institute of Malaysia (NAHRIM) will hugely benefit from this study
Hopefully it will help the responsible agencies to identified the coastal area
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
8
categorized as high risk to the erosion allowing the early necessary precautions to be
taken Also by providing vast and high accuracy wave data the most effective
solution can be applied to the affected area
The government agencies involved in the development especially along the
coastal area will be able to minimize the cost by making the wave information
database as a reference when making a decision for the development of a particular
area The location can be developed rapidly by selecting the most appropriate
location which is protected from strong waves The private sectors especially the
ones which are involved in the engineering project near the coastal area or in the
ocean will also be benefited from this study The wave data is provided by the GPS
buoy at their location able to meet the specification By referring to this data they
will not over engineer their design and maintain the projectrsquos cost They also
minimize the maintenance cost by providing the precise specification for their
project If the design specification is low from its supposition they will have to bear
the high costs of maintenance
The responsible local authority Majlis Daerah Batu Pahat (MDBP) is the
party who benefit directly from this study The output from this study can provide
the guidelines for MDBP to gazette the suitable location for recreational activities
This study is also helpful in providing tidal and wave height data to better understand
the wave behaviour along the coastal area under their jurisdiction By selecting the
ideal location the area can be developed and infrastructures in this location will be
fully utilized by public with low costs of maintenance
The equipment and technique introduced in this study is cost-effective and
flexible to observe the wave data It is cost-effective because the equipment design
does not involve any mechanical part hence no calibration and maintainance is
required The GPS buoy can be robustly handled and able to withstand large waves
because this design lacks of mechanical part The cost of developing this buoy is also
relatively low as compared to other established products in the market however it is
capable of providing the results with high accuracy Although it is a very low cost
product the material and fabrication process was done in detail to sustain its rough
and long-lasting usage The careful design of GPS buoy to specific weight and size
also makes it user-friendly in terms of the transportation sea deployment and setting
up for observation Because of these advantages it can easily be transport to remote
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
9
site and easily deploy from the small boats without any specific equipment and less
operator is required
16 Organization of thesis
This study focused on the development of GPS buoy for ocean monitoring system in
the Straits of Malacca The buoy were used for wave observation of the coast of
Senggarang to obtain the wave data information The thesis for this study is divided
into 6 chapters which are mentioned as follows
i) Chapter one discusses the requirement of this study It comprises of the
background of study problem statement outline of the objectives scope and
significance of this study
ii) Chapter two contains the review of book report and published research
works which are relevant with the wave observation
iii) Chapter three illustrates the methodology adopted in this study The
methodology discussion is on the buoy designing and fabrication buoy
testing data observation data processing and data analysis
iv) Chapter four discusses the result from GPS buoy development data
processing verification and validation process and accuracy assessment
v) Chapter five demonstrate the usefulness of GPS buoy data in wave strength
analysis at off coast Senggarang
vi) Chapter six is the final chapter which comprises of the conclusion achieved
from this study and how future research can be conducted to improve the
technique and enhance the result which will provide more benefits for future
generation
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
10
CHAPTER 2
LITERATURE REVIEW
21 Introduction
The area where the land meets the sea is known as the coastal area The features of
the coastal area vary according to the wind climate sea and the types of rock from
which it is composed of This land portion of most of the worldrsquos coastal zone
consists of sandy beaches In some places the beaches are covered with the coarser
stones known as shingle A delta may be formed and extend the seaward of general
trend of the shoreline where the wave and current action is relatively mild and the
river provides large deposits of sediment In some places there is a break in the
shoreline which produces an estuary or inlet to the area of back-bay Also some
coasts may be fronted by the steep cliffs that may or may not have a small beach at
their toe (Sorensen 2006)
The coastline has been conquered by the human beings for many centuries
initially for the development of ports and maritime trade or fishing harbours to
support the local communities For instance the Port of A-ur built on the Nile prior
to 3000 BC and nearby on the open coast the Port of Pharos around 2000 BC It also
plays a significant role in maintaining an ecological balance among the shoreline
stability beach replenishment nutrient generation and recycling However the
coastal system is under threat due to unmanaged human activities such as pollution
habitat destruction over exploitation of the resources and from natural phenomenon
such as wind and wave (Reeve et al 2004)
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
11
The ocean waves are capable of massive destruction and endless beauty The
unravelling of the mysteries of their generation and predicting their heights have
been a pursuit of sea fairing people and coastal dwellers throughout the history
There are many different kinds of open water waves amongst which are the wind
waves tides and tsunamis (Lighthill 1962) Here the study will be concerned with
the wind waves driven by wind blowing over the surface of the sea
The fluctuations of the global sea level present a direct influence to those who
live near the coast The rise of the sea level has increased the impact on the humanity
with the potential to alter the ecosystems and habitability in coastal regions where a
large ratio of the worldwide population lives (Douglas et al 2001) The monitoring
of the rise of sea level as a reference for the development of future within this area is
very critical Therefore various techniques have been employed for the
measurements of water or sea level such as the coastal water level gauges bottom
pressure gauge satellite altimetry and the wave buoy (Dean amp Dalrymple 2004)
This study will demonstrate the potential of the Global Positioning System (GPS)
buoy for the measurements of the water level
Due to this multidisciplinary nature of this research the literature study is
divided into five subjects The section 22 discusses the related literature about the
ocean wave Then in the section 23 the concept and theory of the GPS technology
was focused Section 24 introduces the water level measurement methods of
measurement and the implementation of latest technology for water level
measurement Section 25 continues with the existing scenario of the wave buoy in
ocean wave measurement The last section comprises of the explanations on
comparison of the GPS buoy data and tide gauge data
22 Ocean wave
The ocean waves are mainly generated by the action of wind on water The waves
are formed initially by a complex process of resonance and sharing action The
surface oscillates up and down sometimes only a few centimetres and sometimes
several meters The oscillations are never exactly regular The successive waves are
of different heights as well as their wave period also varies The pattern of waves
never repeats itself exactly However sometimes this pattern seems to be less
complicated and the intervals between the successive waves are usually longer
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
12
In the open ocean their properties depend on the wind speed duration and
the fetch length The speeds of the higher wind longer durations and longer fetches
are all resulted in larger wind-generated waves When the wind waves leave their
source area they decouple from an atmospheric influence and turns into the swell
waves The swell wave once constituted can travel vast distances spreading in area
and reducing the height but maintaining wavelength and period with minimum loss
of energy However in the nearshore environment wave properties are also affected
by interactions with bathymetry tides and surface currents These nearshore features
can alter the amplitude speed and direction of propagation of the wave field (Reeve
et al 2004)
The waves are disturbances in the ocean that transmits energy from one place
to another The most familiar types of waves are the ones that cause boats to bob up
and down on the open sea and dissipate as breakers on the beaches are generated by
wind on the surface of the ocean Some other types of ocean waves include tsunamis
which are often caused by underwater earthquakes and internal waves that travel
underwater between the masses of water The tides are also a type of wave In this
study a greater emphasis is placed on the waves generated by the wind and tides
221 Wind generate ocean wave
The energy that causes the ocean waves to form is called a disturbing force which
was used as a reference to classify the ocean wave The wave height is not often used
for classification because it greatly varies depending on the depth of water
interference between the waves and other factors The surface has been stretched by
the capillary waves which constitutes as a wind friction Wind which has been
deflected upward creates a partial vacuum and atmospheric pressure that was pushed
down on the wave Therefore it has been evaluated that the circular motion of waves
is virtually friction-free in the deep water The continuation of wind energy can result
in the formation of sea waves as shown in Figure 21 The mature waves sort
themselves into smooth undulations called swells (Tolman 2008) The growth of
wind generated waves is determined by the wind duration wind speed and fetch
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
13
Figure 21 Wind generate the waves (adopted from Florida Center for Instructional
Technology 2005)
The waves are sustained because the restoring forces (gravity in wind-
generated waves) continued to pass the water level of the calm seas which results in
oscillation The speed of waves wavelength period and height are inter-related with
each other A circular path can be maintained only by the water in waves when
water depth from the surface to bottom is greater than one-half of the wave length
(deep-water waves) The waves which have not been generated by the wind include
tides internal waves storm surges and tsunamis (Soares amp Carvalho 2012)
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
14
222 Tidal wave
The tides are the rise and fall of sea levels which has been caused by the combined
effects of the gravitational forces exerted by Moon Sun and the rotation of the Earth
Every day almost two equal high tides and low tides have been experienced by some
shorelines known as a semi-diurnal tide Some locations experience only one high
and one low tide each day called a diurnal tide Some locations experience two
uneven tides a day or sometimes one high and one low each day this is called a
mixed tide The time and amplitude of the tides are influenced by variable factors
such as the alignment of the Sun and Moon by the pattern of tides in the deep ocean
by the systems of the oceans and by the shape of the coastline and nearshore
bathymetry (Thurman amp Trujillo 2004)
The variation of the tides depends upon the timescales ranging from hours to
years due to numerous influences To make accurate records the tide gauges at fixed
stations measures the level of water over time The variations have been ignored by
the gauges caused by waves with periods shorter than minutes These data are
compared to the reference or datum level usually called mean sea level While tides
are usually the largest source of short term sea level fluctuations the sea levels are
also subject to forces such as wind and barometric pressure changes resulting in the
storm surges especially in shallow seas and near the coasts (Talley et al 2001)
2221 Tides characteristic
The tidal changes usually occur through the following stages (i) The rise of sea level
over several hours covering the intertidal zone flood tide (ii) The water rises to its
highest level reaching a high tide (iii) Sea level falls over several hours revealing
the intertidal zone ebb tide (iv) The water stops falling reaching the low tide
The tidal streams are the oscillating currents which have been produced by
the tides The moment when the tidal current ceases is called slack water or slack
tide The tide then reverses direction and is said to be turning The slack water
usually occurs near high water and low water but there are locations where the
moments of slack tide differ significantly from those of high and low water There
are three type of diurnal as shown in Figure 22 The semi-diurnal tide (two high
waters and two low waters each day) is experienced by the Peninsular Malaysia On
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
15
a given day the two high waters are typically not having the same height These are
the higher high water and the lower high water in the tide tables Similarly the two
low waters each day are the higher low water and the lower low water When the
Moon is over the equator the daily inequality is not consistent and is generally small
(Reeve et al 2004)
Figure 22 Types of tides and tidal phases (adopted from National Oceanic and
Atmospheric Administration 2013)
2222 Tidal flow
The analysis and data collection is very difficult for the influence of tides on the
current flow A tidal height is a simple number which applies to a wide region
simultaneously A flow has both a magnitude and a direction both of which can vary
substantially with depth and over short distances due to local bathymetry
Nevertheless the current analysis is similar to tidal analysis In the simple case at a
given location the flood flow is in mostly one direction and the ebb flow in another
direction The flood velocities are given a positive sign and ebb velocities a negative
sign The analysis proceeds as though these are tide heights
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
16
In more complex situations the main ebb and flood flows do not dominate
Instead the flow direction and magnitude trace an ellipse over a tidal cycle instead of
along the ebb and flood lines In this case analysis might proceed along pairs of
directions with the primary and secondary directions at right angles An alternative
is to treat the tidal flows as complex numbers as each value has both a magnitude
and a direction The information of the tide flow is most commonly seen on the
nautical charts presented as a table of flow speeds and bearings at hourly intervals
with separate tables for spring and neap tides The timing is relative to high water at
some harbour where the tidal behaviour is similar in pattern though it may be far
away As with the predictions regarding the height of tides the tide flow predictions
based only on the astronomical factors do not incorporate weather conditions which
can completely change the outcome (Whitney and Richard 2007)
223 Wave characteristics
The waves do not usually have such a size height and length that are similar to each
other although in fact these waves move in the same direction The data from ocean
waves is random and not always consistent and requires the use of statistical
techniques to solve them However the large waves or waves in shallow waters are
not very random as compared to the small waves or waves in deep water Therefore
after the wave energy decreases or becomes weak the deposition and eroded
materials will occur
Prior to deeply understand the analysis in respect of linear waves the main
physical properties of waves that used must be known in advance This theory
connects three important parameters of the basic wave which is wave period (T)
wave length (L) and wave height (H) Figure 23 shows the basic features of a wave
propagation velocity (c) at a water depth (d) The water depth is measured from the
calm water level to the sea bottom (Sorensen 2006)
Apart from the above mentioned characteristics some useful information is
provided by the slope of the waves to understand its behaviour It can be reflected by
the reduction gradient waves (HL) whether the waves were stable or break If the
value (HL) does not exceed 17 the waves are in stable condition and if the value
(HL) exceeds 17 the waves are unstable and breaking waves will occur
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
17
Figure 23 Basic characteristics of wave (adopted from Sorensen 2006)
224 Wave energy
The ocean wave comprises of both the kinetic and potential energy Kinetic energy is
possessed by the movement of water molecules in the wave whereas the potential
energy by water molecules that have been displaced vertically against the gravity and
surface tension
At the wavelength of most ocean waves the total energy (E) per unit area of
wave is approximately
E = 0125 (gρH2) 21
where
ρ ndash is the density of water (gcm-3)
g ndash is the acceleration due to gravity (98 ms-2)
H ndash is the wave height (m)
E ndash is energy measured in joule per square meter (Jm-2)
On the basis of above equation three various factors which contribute to the
wave energy are gravity (g) water density (ρ) and wave height (H) Because water
density changes very little in open ocean and g is constant the total energy of a wave
depends primarily on its height (Segar 1998)
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
18
225 Spectral analysis
There are two main approaches which explain how the complex waves should be
treated These approaches include the spectral analysis and wave by wave analysis
The more powerful and popular of these two approaches is spectral analysis The
assumption of the spectral analysis is that the sea state can be considered as a
combination or superposition of a large number of regular sinusoidal wave
components with different frequencies heights and directions This assumption is
very useful in wave analysis since sea states are in fact composed of the waves from
a number of different sources each with its own height period and direction of travel
characteristics (Hessner et al 2001)
Mathematically the spectral analysis is based on the Fourier Transform of the
sea surface The Fourier Transform allows any continuous zero mean signal like a
time series record of the sea surface elevation to be transformed into a summation of
simple sine waves These sine waves are the components of the sea state each with a
distinct height frequency and direction In other words the method of the spectral
analysis determines the distribution of wave energy and average statistics for each
wave frequency by converting the time series of the wave record into a wave
spectrum This is essentially a transformation from the time-domain to the
frequency-domain and is accomplished most conveniently with the usage of a
mathematical tool known as the Fast Fourier Transform (FFT)
The spectral approach indicates the frequencies which have significant
energy content as well as the direction wave energy is moving at each frequency A
wave spectrum can readily be plotted in a frequency to energy density graph which
can provide important information about a wave sample and the corresponding
conditions of the ocean In fact a general shape of the plot reveals a great deal
whether seas or swell predominate the number of distinct swells present etc For
example during strong wind events the spectrum tends to have a broad central peak
On the contrary for the swell that has propagated a long distance from the source of
generation the spectrum tends to have a single sharp low-frequency peak
(Holthuijsen 2007)
In addition to the two methods mentioned the power of ocean waves can also
be expressed in terms of density for every wave frequency (Kaihatu et al 2007)
This technique is known as the Power Spectral Density (PSD) The function of PSD
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
19
shows the strength of the variations (energy) as a function of frequency In other
words it shows at which frequencies the variations are strong and at which
frequencies the variations are weak The unit of PSD is energy per frequency
(m2sHz) and you can obtain energy within a specific frequency range by integrating
PSD within that frequency range Looking at PSD is like looking at the simple time
series plot except that we look at time series as a function of frequency instead of a
function of time The frequency is a transformation of time and considering the
variations in the domain of frequency is just another way to look at variations of time
series data PSD tells us the ranges of frequency at which the variations are strong
and that might be quite useful for further analysis (WAFO 2000)
PSD is a very useful tool if you want to know the frequencies and amplitudes
of oscillatory signals in the time series data For example letrsquos suppose that you are
operating a factory with many machines and some of them have motors inside You
detect unwanted vibrations from somewhere You might be able to get a clue to
locate offending machines by looking at PSD which would give you the frequencies
of vibrations The technique is widely used in fields which are associated with
electrical and electronic for computing power per unit frequency Moreover this
technique is very helpful in analyzing the radio wave signals These techniques are
developed in order to analyze the measured wave data either from the field (ocean
sea lake or coastal area) or from the laboratory measurement The data measured
by wave gauges wave logger wave staff GPS or any other instruments that used
for the collection of data can be examined by using this technique (Karimpour
2015)
23 Global Navigation Satellite System (GNSS)
The term lsquoGlobal Navigation Satellite Systemrsquo (GNSS) refers to the constellation of
satellites which provides the autonomous geo-spatial positioning along with the
global coverage (Dow et al 2009) The satellites transmit the signals from space to
allow the small electronic receivers to determine their location (longitude latitude
and altitudeelevation) to high precision (within a few metres) GNSS consists of
several satellite systems that have been developed by various countries The systems
are NAVSTAR Global Positioning System (GPS) developed by United States
America global operational GNSSs (GLONASS) developed by Russian BeiDou
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
20
Navigation Satellite System developed by China Galileo developed by European
Unionrsquos GPS Aided GEO Augmented Navigation (GAGAN) and Indian Regional
Navigation Satellite System (IRNSS) developed by India (Hofmann-Wellenhof et al
2007) Further the France and Japan cannot be left behind in the procedure of
developing regional navigation satellite systems and will be launch in the near future
This study only emphasized on the GPS because it was used to observe the entire
fieldwork data
231 Global Positioning System
The Global Positioning System is based on constellation of 24 satellites as shown in
Figure 24 It provides the information regarding the time and location in all weather
conditions anywhere on or near the earth where there is an unobstructed line of
sight to four or more GPS satellites This system provides critical capabilities to
military civilian and commercial users around the world It is maintained by the
United States government and is freely accessible to anyone with a GPS receiver
(Misra and Enge 2006)
Figure 24 The GPS satellite orbiting earth (adopted from Misra and Enge 2006)
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
21
In 1960 the first satellite navigation system called Transit was successfully
developed and tested by the Navy of United States A constellation of five satellites
have been used by this system and could provide a navigational fix approximately
once per hour After this the Timation has also been developed by the US in 1967
which proved the ability to place accurate clocks in space the technology required
by GPS In 1970 the ground-based Omega Navigation System became the first
worldwide radio navigation system when successfully transmitted signal based on
phase comparison from pairs of stations But this system has some limitations and
then drove the need for a more universal navigation solution with greater accuracy
In 1973 the GPS project has been developed by the US Department of
Defence to overcome the limitations of previous navigation systems Originally the
GPS was run with 24 satellites and became fully operational in 1994 The GPS was
fully utilized in a wide range of application such as to determining the position fixes
on offshore oil rigs navigation construction transportation and many other
possibilities as well In the modern world today the GPS equipments are handheld
and even integrated into a smart phone (Kaplan and Hegarty 2005)
232 GPS signals
According to Leick et al (2015) the GPS satellite positioning system originally
designed for use by the Department of Defence and the US military which
currently comprises of 32 active positioning satellites These satellites broadcast a
unique signal on two carrier frequencies to enable the receivers of GPS on or near the
earthrsquos surface to determine the location The carrier which are transmitted in the L
band of microwave radio frequencies are identified as the L1 signal with a frequency
of 157542 MHz and the L2 signal at a frequency of 122760 MHz
The GPS signals broadcasts also include numerous types of information
which are modulated upon these carrier waves in the form of binary bits by using the
technique of phase modulation The information included in the broadcast message is
the almanac broadcast ephemeris satellite clock correction coefficients coefficients
of the ionosphere correction and the satellite health The entire information has been
summarized into three various information bits as mentioned below
i) Pseudo random code ndash An ID code to identify the satellite which is
transmitting the data
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
22
ii) Ephemeris data ndash Constantly transmitted by each satellite which contains
information about the health of the satellite current date and time and also
helps in determining the position
iii) Almanac data ndash Provides the information to the GPS receiver regarding the
location of each satellite throughout the day It shows the orbital information
for the satellites
233 Errors in GPS observations
The accuracy of the GPS system is generally dependent on the frequencies of the
microwave radio broadcast to the receiver The microwave can be affected during
their transmission by several sources of error that would degrade the GPS signal Xu
(2003) and Zhang et al (2007) described the sources of error as below
i) Receiver clock error ndash The time is kept on board the satellite by atomic
clocks with a precision of 1 nanosecond which is far more accurate as
compared to the quartz clock built in the ground receiver
ii) Ionospheric and tropospheric refraction ndash The ionospheric refraction occurs
50 to 1000 km above the earth whereas the tropospheric refraction seems to
occur from the earth surface to 80 km above the earth As they travel through
these layers the signals are slowed down
iii) Multipath interference ndash Some signals are received directly and others are
received after they have been reflected from adjacent features such as tall
buildings and steel fences
iv) Weak geometry ndash When the satellites are positioned in a tight grouping and
should be placed at wide angles relative to each other it will be resulted in
the weak geometry
v) Satellite orbital data ndash The errors associated with the satellite orbital data are
also known as ephemeris errors where the data for satellite location is not
accurate
vi) Setup errors ndash During the setup of equipment some common errors occur
which are centring the height measuring of antenna reference
vii) Selected Availability (SA) ndash A denial of accuracy that was turned off in May
2000
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
23
Most of the errors have been discussed which can be surmounted by using
differential positioning surveying techniques But for a longer baseline more
sophisticated processing is required to deal with the natural and manmade errors
(Kavanagh 2006)
234 GPS segment
The GPS system can be categorized into three major segments which include the
space segment control segment and the user segment (Bhatta 2010) The US Air
Force is the sole authority to this system that develops maintains and operates the
space and control segments as shown in Figure 25
Figure 25 Segments of the GPS system (adopted from Snider 2016)
2341 Space segment
The space segment consists of 24 satellites which are operating in six orbital planes
spaced at 60 degree intervals around the equator Four additional satellites are held in
reserve as spares The orbital planes are inclined to the equator at 55 degree The
orbital period is 12 sidereal hours so that the satellite passes over the same location
twice a day The orbits are arranged so that at least six satellites are always within
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
24
line of sight from almost everywhere on the surface of the earth On December 2012
the number of GPS satellite constellations increased to 32 satellites The additional
satellites significantly improve the precision of the calculations by providing
redundant measurements The increased number of satellites also changed the
constellation of satellites to an uneven arrangement The new arrangement was
shown to enhance the availability and reliability of the system as compared to the
uniform system in case of the failure of multiple satellites The nine satellites on this
system are visible at any time from any point on the ground to make sure about the
considerable redundancy over the minimum of four satellites which are required for
a position
The extremely precise and expensive atomic clocks are used in the GPS
satellite to control the timings of signal transmission If the same clocks have been
used by the receiver the cost would be higher and would also require the users to
become enough trained that they can handle the hazardous material Thus the
clockrsquos receivers are controlled by the oscillations of the quartz crystal which are
also precise but less accurate in contrast with the atomic clocks However an
affordable receiver will be produced by these relatively low cost timing devices
2342 Control segment
The control segment consists of twelve monitoring stations including those at
Colorado Spring on the Island of Hawaii Ascension Diego Garcia and Kwajalein
The signals from the satellite are monitored and their orbits are tracked at the
monitoring systems The tracking information is transmitted to the master control
station in the 50th Space Wingrsquos 2nd Space Operation Squadron which is located at
Schriever Air Force Base in Colorado Spring The master control station will use this
data to make precise future predictions of satellite orbits and their clock correction
parameters The information is uploaded to the satellite and transmitted as a part of
broadcast messages to be used by the receivers to predict the satellite positions and
the systematic error of their clock
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
167
REFERENCES
Abidin H Z (1999) Monitoring Sea Level Using GPS Proceeding of the
International Seminar on Application of Seawatch Indonesia Information
System for Indonesian Marine Resources Development Jakarta Indonesia
Agardy M T (1993) Accommodating ecotourism in multiple use planning of
coastal and marine protected areas Ocean amp Coastal Management 20(3)
219-239
Arroyo-Suarez E N Hsiao V amp Mabey L D L (2005) Implementation of a
positioning and telemetry buoy to determine chart datum for hydrographic
survey applications In OCEANS 2005 Proceedings of MTSIEEE (pp 1726-
1728) IEEE
Bender L C Guinaso Jr N L Walpert J N amp S D Howden (2010a) A
comparison of methods for determining significant wave heights - Applied to
a 3-m discus buoy during hurricane Katrina Journal of Atmospheric and
Oceanic Technology 27 1012 ndash 1018
Bender L C Howden S D Dodd D amp Guinasso N L (2010) Wave Heights
during Hurrincane Katrina An Evaluation of PPP and PPK Measurements of
the Vertical Displacement of the GPS Antenna Journal Atmospheric and
Oceanic Technology 27 1760 ndash 1768
Bernatchez P amp Dubois J M M (2008) Seasonal quantification of coastal
processes and cliff erosion on fine sediment shorelines in a cold temperate
climate north shore of the St Lawrence maritime estuary Queacutebec Journal of
Coastal Research 24(1) 169 - 180
Bhatta B (2010) Global Navigation Satellite Systems Insights into GPS
GLONASS Galileo Compass and Others BS Publications
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
168
Bonnefond P ExertierP Laurain O Menard Y Orsoni A Jan G amp Jeansou
E (2003) Absolute calibration of Jason-1 TopexPoseidon altimeters in
Corsica Marine Geodesy 26 261 ndash 284
Born G H Parke M E Axelrad P Gold K L Johnson J Key K W amp
Kubitschek D G (1994) Calibration of TOPEX altimeter using GPS buoy
Journal of Geophysical Research 99(C12) 24517 ndash 24526
Bouin M N Ballu V Calmant S Cheng K Shum C amp Testut L (2003)
Absolute height of sea surface by trajectory of GPS antennae over submerged
pressure gauges Presented at the AGU Fall Meeting San Francisco
California United State America
Buble G Bennett R A amp Hreinsdottri S (2010) Tide gauge and GPS
measurements of crustal motion and sea level rise along the eastern margin of
Adriatic Journal of Geophysical Research 115(B2)
Campbell J B amp Wynne R H (2011) Introduction to remote sensing New
York United State America Guilford Press
CDIP (2015) Wave dynamics Available online at httpcdipucsdedu Retreived
on 15122015
Chai T amp Draxler R R (2014) Root mean square error (RMSE) or mean
absolute error (MAE) ndash Arguments against avoiding RMSE in the literature
Geoscientific Model Development 7 1247 ndash 1250
Chang C C Lee H W amp Tsui I F (2002) Preliminary test of tide independent
bathymetric measurement based on GPS Geomatics Research Australasis
76 23-36
Chang C C amp Sun YD (2004) Application of a GPS-Based Method to Tidal
Datum Transfer The Hydrographic Journal 112 15 ndash 20
Chen W Hu C Li Z Chen Y Ding X Gao S amp Ji S (2004) Kinematic
GPS Precise Point Positioning for Sea Level Monitoring with GPS Buoy
Journal of Global Positioning Systems 3(1-2) 302 ndash 307
Cheng K Shum C Han C Yi Y amp Martin D (2001) Application of GPS-
buoy water level instrument for radar altimeter calibration Proceeding of the
Gravity Geoid and Geodynamics 2000 GGG2000 IAG International
Symposium Berlin
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
169
Cheng K C Kuo C Y Shum C K amp NIU X R (2008) Accurate linking of
Lake Erie water level with shoreline datum using GPS buoy and satellite
altimetry Terrestrial Atmospheric and Oceanic Sciences 19 53 ndash 62
Cheng K C Calmant S Kuo C Y Tseng H Z Shum C K Seyler F amp
Silva J S D (2009) Branco river stage gradient determination and Amazon
hydrologic studies using GPS Water level measurements Marine Geodesy
32 267 ndash 283
Chia C C amp Yuan D S (2004) Application of a GPS based method to tidal
datum transfer Hydrographic Journal 112 15 ndash 20
Chiang E P Zainal Z A Narayana P A A amp Seetharamu K N (2003)
Potential of renewable wave and offshore wind energy sources in Malaysia
Proceedings of the International Symposium on Renewable Energy
Environment Protection amp Energy Soilltion for Sustainable Development
Kuala Lumpur Malaysia
Christensen E J Haines B J Keihm S J Morris C S Norman R A
Purcell G H Williams B G Wilson B D Born G H Parke M E
Gill S K Shum C K Tapley B D Kolenkiewicz R amp Nerem R S
(1994) Calibration of TOPEXPOSEIDON at Platform Harvest Journal of
Geophysical Research 99(C12) 24465 ndash 24485
Collins C O Lund B Waseda T amp Graber HC (2014) On recording sea
surface elevation with accelerometer buoys lessons from ITOP (2010)
Ocean Dynamic 64(6) 895 ndash 904
Cui J amp Kouguchi N (2011) Ocean Wave Observation by GPS Signal Paper
presented at IEEE Oceanic Engineering Society Santander Spain
Dach R Hugentobler U Fridez P amp Meindl M (2007) User manual of the
Bernese GPS Software Version 50 Astronomical Institute University of
Bern
Datawell (2014) Datawell Waverider Reference Manual (WR-SG DWR-MkIII
DWR-G) Retreived on November 18 2014 from
httpdownloaddatawellnldocumentationdatawell_manual_dwr-
mk3_dwrg_wr-sg_2010ndash07ndash28pdf
Daud M E Sagiya T Kimata F amp Kato T (2008) Long-baseline quasi-real
time kinematic GPS data analysis for early tsunami warning Earth Planet
Space 60 1191 ndash 1195
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
170
Dawidowicz K (2014) Sea level changes monitoring using GNSS technology ndash a
review of recent efforts Acta Adriatica 55(2) 145 ndash 162
Dawod G M amp Abdel-Aziz T M (2003) Establishment of a precise geodetic
control network for updating the River Nile maps Proceedings of Al-Azhar
Engineering 7th International Conference Cairo Mesir
Dean R G amp Dalrymple R A (2004) Coastal processes with engineering
applications United Kingdom Cambridge University Press
Department of Irrigation amp Drainage Malaysia (2013) Coastal Management
Available on line at httpwwwwatergovmy Retrieved 24 August 2014
Dewar P amp Hannah J (2005) An Assessment of the Accuracy of Three Tidal
Datum Transfer Procedures in a Harbour Environment The Hydrographic
Journal 117 3 ndash 7
Doong D J Lee B C amp Kao C C (2011) Wave Measurements Using GPS
Velocity Signals Sensors 11 1043 ndash 1058
Douglas B Kearney M T amp Leatherman S P (Eds) (2001) Sea level rise
History and consequences California United State America Academic
Press
Dow J M Neilan R E amp Rizos C (2009) The International GNSS Service in a
changing landscape of Global Navigation Satellite Systems Journal Geodesy
83 191 ndash 198
Dunne S Soulat F Caparrini M Germain O Farres E Barroso X amp
Ruffini G (2005 June) Oceanpalsupspl rega GPS-reflection coastal
instrument to monitor tide and sea-state In Oceans 2005-Europe (Vol 2 pp
1351-1356) IEEE
El-Rabbany A (2006) Introduction to GPS The Global Positioning System
Massachusetts United State America Artech House Publishers
Envirtech (2014) Envirtech MKI-3 Directional ndash ODAS ndash MAWS Retreived on
November 18 2014 from httpwwwenvirtechhkindexhtml
Envirtech (2015) MKI-4 Envirtech Easy to Deploy Tsunami Buoy Retreived on
May 13 2015 from httpwwwenvirtechcomdocsMKI-4pdf
Florida Center for Instructional Technology (2005) Beach Profiles ndash Response to
Oceanic Conditions Retreived on January 20 2016 from
httpfcitusfedufloridateachersciencemod2beachprofileshtml
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
171
Fowler C M R (1990) The solid earth an introduction to global geophysics
United Kingdom Cambridge University Press
Fugro (2012) Fugro Launches Seawatch Wind Lidar Buot at Global Offshore
Wind Retreived on November 18 2014 from
httpwwwoceanornonewsroomNews_overview_2012Lidar
Gesch D amp Wilson R (2001) Development of a seamless multisource
topographic bathymetric elevation model of Tampa Bay Marine Technology
Society Journal 35(4) 58 ndash 64
Ghazali N H M (2006) Coastal erosion and reclamation in Malaysia Aquatic
Ecosystem Health amp Management 9(2) 237 ndash 246
Goring D (2007) Transferring a Survey Datum Across Water Mulgor Consulting
Ltd Christchurch Retrieved on February 24 2015 from
httpwwwtidemanconzSurveyDatums Retreived on 1st October 2014
Grebenitcharsky R S Rangelova E V amp Sideris M G (2005) Transformation
between gravimetric and GPSlevelling-derived geoids using additional
gravity information Journal of Geodynamics 39 527 ndash 544
Gulev S K Grigorieva V Sterl A amp Woolf D (2002) Global-scale wave
observations from voluntary observing ships Assessment of reliability and
potentialities for global and off-shore regions studies In Proceedings of the
7th international workshop on wave hindcasting and forecasting (p 11)
Haines B Bonnefond P Born G Exertier P Gill S Jeansou E Kubitschek
D Jan G Laurain O Menard Y amp Orson A (2002) Calibrating the
JASON-1 measurement system Initial results from the Corsica and Harvest
verification experiments Presented at the AGU Fall Meeting San Francisco
California United State America
Harigae M Yamaguchi I Kasai T Igawa H Nakanishi H Murayama T amp
Suko H (2005) Abreast of the waves Open-sea sensor to measure height
and direction GPS World 16(5)
He Y Shen H amp Perrie W (2006) Remote Sensing of Ocean Waves by
Polarimetric SAR Journal of Atmospheric and Oceanic Technology 23
1768 ndash 1773
Hein G W Landau H amp Blomenhofer H (1990) Determination of
instantaneous sea surface wave heights and ocean currents using satellite
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
172
observations of the Global Positioning System Marine Geodesy 14 217 ndash
224
Herbers T H C Jessen P F Janssen T T Colbert D B amp MacMahn J H
(2012) Observing ocean surface waves with GPS-tracked buoys Journal of
Atmospheric and Oceanic Technology 29 944ndash959
Hess K W (2001) Generation of Tidal Datum Fields for Tampa Bay and the New
York Bight US Department of Commerce National Oceanic and
Atmospheric Administration Silver Spring Maryland NOAA Technical
Report NOS CS 11
Hessner K Reichert K Dittmer J Borge J C N amp Guumlnther H (2001)
Evaluation of WaMoS II wave data In Ocean Wave Measurement and
Analysis (pp 221-230) ASCE
Hocker B amp Wardwell N (2001) Tidal datum determination and VDatum
evaluation with a GNSS Buoy In Proceedings of the 23rd International
Technical Meeting of The Satellite Division of the Institute of Navigation
(ION GNSS 2010) (pp 2076-2086)
Hofmann-Wellenhof B Lichtenegger H amp Wasle E (2007) GNSSndashglobal
navigation satellite systems GPS GLONASS Galileo and more Berlin
Heidelberg Springer Science amp Business Media
Holthuijsen L H (2007) Waves in oceanic and coastal waters United Kingdom
Cambridge University Press
Hong J Back K Park U Lee D amp Cha S (2008) Determination of ocean
datum using GPS buoy observation data The International Archives of the
Photogrammetry Remote Sensing and Spatial Information Sciences 37 685
ndash 688
Hou D Hamada M Yoo Y J amp Kouguchi N (2007) Evaluation test result on
wave direction measurement using GPS buoy In OCEANS 2006-Asia
Pacific (pp 1-5) IEEE
Inch K W (2014) Surf Zone Hydrodynamics Measuring Waves and Currents
Retrieved on December 12 2014 from
httpwwwgeomorphologyorguksitesdefaultfilesgeom_tech_chapters32
3_SurfZoneHydrodynamicspdf
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
173
Jeans G Bellamy I Vries J J amp Weert P V (2003) Sea Trial of the New
Datawell GPS Directional Waverider Proceedings of the IEEEOES Seventh
Working Conference 145 ndash 147
Johnson D Stocker R Head R Imberger J amp Pattiaratchi C (2003) A
compact low-cost GPS drifter for use in the oceanic nearshore zone lakes
and estuaries Journal of Atmospheric Oceanic Technology 20 1880 ndash 1884
Joodaki G Nahavandchi H amp Cheng K (2013) Ocean Wave Measurement
Using GPS Buoys Journal of Geodetic Science 3(3) 163 ndash 172
JUPEM (2000) Circular of the Director General of Survey and Mapping ndash ldquoNot
publishedrdquo
JUPEM (2002) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 5
JUPEM (2005) Pekeliling Ketua Pengarah Ukur dan Pemetaan Malaysia Bil 10
JUPEM (2016) Data Air Pasang Surut Retreived on July 24 2014 from
httpswwwjupemgovmyv1myproduk-perkhidmatandata-air-pasang-
surut
Kaihatu J M Veeramony J Edwards K L amp Kirby J T (2007) Asymptotic
behavior of frequency and wave number spectra of nearshore shoaling and
breaking waves Journal of Geophysical Research Oceans 112(C6)
Kaplan E amp Hegarty C (Eds) (2005) Understanding GPS principles and
applications Massachusetts United State America Artech House Publishers
Karimpour A (2015) Oceanlyz Ocean wave analyzing toolbox MATLAB
Toolbox Version 13 User manual
Kato T Terada Y Ito K Hattori R Abe T Miyake T Ko-shimura S amp
Nagai T (2005) Tsunami due to the 2004 Sep-tember 5th off the Kii
peninsula earthquake Japan recorded by a new GPS buoy Earth Planets
Space 57 297 ndash 301
Kato T Terada Y Kinoshita M amp Kakimoto H (2000) Real-time observation
of tsunami by RTK-GPS Earth Planets and Space 52 (10) 841 ndash 846
Kato T Terada Y Kinoshita M Kakimoto H Isshiki H amp Moriguchi T
(2001) A new tsunami monitoring system using RTK-GPS Proceeding of
the US National Tsunami Hazard Mitigation Program Review and
International Tsunami Symposium 7 ndash 10
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
174
Kato T Terada Y Nagai T amp Koshimura S (2010) Tsunami Monitoring
System Using GPS Buoy ndash Present Status and Outlook IEEE Geoscience and
Remote Sensing Symposium 65(4) 3043 ndash 3046
Kavanagh B F (2006) Surveying Principles and Applications 7th ed New
Jersey United State America Pearson Prentice Hall
Kendall M G Stuart A amp Ord J K (1987) Kendalls Advanced Theory of
Statistics Vol 1 Distribution Theory 6th ed New York Oxford University
Press
Kenney J F amp Keeping E S (1962) Mathematics of Statistics 3rd ed Princeton
New Jersey Van Nostrand
Key K Parke M amp Born G (1998) Mapping the sea surface using GPS buoy
Marine Geodesy 21 67 ndash 79
Kotsakis C (2008) Transforming ellipsoidal heights and geoid undulations
between different geodetic reference frames Journal of Geodesy 82(4-5)
249-260
Kouba J amp Heroux P (2001) Precise Point Positioning Using IGS orbit and
Clock Products GPS Solutions 5(2) 12 ndash 28
Krogstad H E Barstow S F Aasen S E amp Rodriguez I (1999) Some recent
developments in wave buoy measurement technology Journal of Coastal
Engineering 37(3ndash4) 309ndash329
Kruizinga G L H (1997) Validation and applications of satellite radar altimetry
University of Texas at Austin
Larson K M Lofgren J S amp Rudiger (2013) Coastal sea level measurements
using a single geodetic GPS receiver Advances in Space Research Journal
51(8) 1301 ndash 1310
Lee K S amp Seng L Y (2009) Simulation Studies on the Electrical Power
Potential Harnessed by Tidal Current Turbines Journal of Energy and
Environment 1(1) 18 ndash 23
Lehner S Schulz-Stellenfleth J Schaumlttler J B H Breit H amp Horstmann J
(2000) Wind and wave measurements using complex ERS-2 wave mode
data IEEE Transactions on Geoscience and Remote Sensing 38(5) 2246 ndash
2257
Leick A Rapoport L amp Tatarnikov D (2015) GPS satellite surveying New
Jersey United State America John Wiley amp Sons
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
175
Li R Bedford K Shum C K Niu X Zhou F Velissariou V amp Zhang A
(2006) Digitalization of coastal management and decision making supported
by multi-dimensional geospatial information and analysis In Proceedings of
the 2006 international conference on Digital government research (pp 429-
430) Digital Government Society of North America
Liebsch G Novotny K amp Dietrich R (2002) Comparison of multimission
altimetric sea surface heights with tide gauge observations in the Southern
Baltic Sea Marine Geodesy 25 213 ndash 234
Lighthill M J (1962) Physical interpretation of the mathematical theory of wave
generation by wind Journal of Fluid Mechanics 14(2) 385 ndash 398
MacMahan J Brown J amp Thornton E (2009) Low-cost handheld Global
Positioning System for measuring surf-zone currents Journal of Coastal
Research 25 (3) 744 ndash 754
Marghany M M (2000) Wave spectra and shoreline changes studies by remote
sensing Universiti Putra Malaysia PhD Thesis
Marshall A amp Denys P (2009) Water level measurement and tidal datum
transfer using high rate GPS buoys New Zealand Surveyor (299) 24
McDonnell M J (1981) Box-filtering techniques Computer Graphics and Image
Processing 17(1) 65 ndash 70
Misra P amp Enge P (2006) Global Positioning System Signals Measurements
and Performance 2nd ed Lincoln Massachusetts United State America
Ganga Jamuna Press
MET (2014) Wave forecasting for Malaysia Retrieved on April 14 2015 from
httpwwwmetgovmywebmetmalaysiaforecastmarinewavewindcharts
Muzathik A M Wan Nik W B Samo K B amp Ibrahim M Z (2011) Ocean
Wave Measurement and Wave Climate Prediction of Peninsular Malaysia
Journal of Physical Science 22(1) 77 ndash 92
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2007)
Proposal of Hybrid Tsunami Monitoring Network System Consisted of
Offshore Coastal and On-site Wave Sensors Coastal Engineering 49(1) 213
ndash 223
Nagai T Kato T Moritani N Izumi H Terada Y amp Mitsui M (2006)
Offshore Tsunami Monitoring Network Design Using GPS Buoys and
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
176
Coastal On-Site Sensors Proceeding of the Coastal Engineering Conference
30 1529 ndash 1534
Nagai T Ogawa H Terada Y Kato T amp Kudaka M (2003) Offshore wave
tsunami and tide observation using GPS buoy Proceedings of Annual
Meeting of Korean Society of Coastal and Ocean Engineers Korean Society
of Coastal and Ocean Engineers 14 137 ndash 142
Nagai T Satomi S Terada Y Kato T Nukada K amp Kudaka M (2005) GPS
buoy and seabed installed wave gauge application to offshore tsunami
observation Proceedings of the Fifteenth International Offshore and Polar
Engineering Conference South Korea 292 ndash 299
National Data Buoy Center (NDBC) (2010) Retrieved on January 4 2014 from
httpwwwndbcnoaagov
National Oceanic and Atmospheric Administration (2013) Retrieved on March
10 2014 from httpco-opsnosnoaagovimagesrestfig6gif
OrsquoReilly W C Herbers T H C Seymour R J amp Guza R T (1996) A
Comparison of Directional Buoy and Fixed Platform Measurements of
Pacific Swell Journal of Atmospheric and Oceanic Technology 13(1) 231 ndash
238
Oceanor (2014) Oceanor Seawatch Deep Sea Module Retrieved on January 18
2015 from httpwwwoceanornoseawatchbuoys-and-sensorSeawatch-
deep-sea-module
Ohta Y Meilano I Sagiya T Kimata F amp Hirahara K (2006) Large surface
wave of the 2004 Sumatra-Andaman earthquake captured by the very long
baseline kinematic analysis of 1-Hz GPS data Earth Planets Space 58 153 ndash
157
Parker B Milbert D Hess K amp Gill S (2003) National VDatumndashThe
implementation of a national vertical datum transformation database
InProceeding from the US Hydrorsquo2003 Conference (pp 24-27)
Pinardi N amp Woods J (2002) Ocean Forecasting Conceptual Basis and
Applications 1st ed New York United State America Springer
Reeve D Chadwick A amp Fleming C (2004) Coastal engineering processes
theory and design practice Florida United State America CRC Press
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
177
Salleh A M amp Daud M E (2015) Development of a GPS Buoy for Ocean
Surface Monitoring Initial Results World Academy of Science Engineering
and Technology 9(6) 1579 ndash 1582
Salleh A M amp Daud M E (2015a) A Buoy IP Rights Malaysia 15-01410-
0101
Salleh A M amp Daud M E (2016) An observation technique and GPS buoy
processing strategy for ocean surface monitoring in Dong-Keon Kim D K
Jung J and Seo J (Ed) Advances in Civil Architectural Structural and
Constructional Engineering London Taylor amp Francis Group 347 ndash 350
Salleh A M amp Daud M E (2016a) GPS-Based Ocean Wave Monitoring System
for The Strait of Malacca Proc of the 2016 Advanced Research in
Engineering and Information Technology International Conference
Bandung Indonesia Maltesas pp 68
Schmidt W Woodward B Millikan K Guza R Raubenheimer B amp Elgar S
(2003) A GPS-Tracked Surf Zone Drifter Journal of Atmospheric and
Oceanic Technology 20 (7) 1069 ndash 1075
Schueler T Zimmermann B Riedal B amp Hein G W (2003) Radar altimeter
calibration of the Envisat satellite An autonomous system of high precision
for instantaneous sea surface height determination Proceeding of the NTM
2003-National Technical Meeting Anaheim California United State
America 397 ndash 406
Schuler D L Lee J S Kasilingam D amp Pottier E (2004) Measurement of
ocean surface slopes and wave spectra using polarimetric SAR image data
Remote Sensing of Environment 91(2) 198 ndash 211
Schulz-Stellenfleth J amp Lehner S (2004) Measurement of 2-D sea surface
elevation fields using complex synthetic aperture radar data IEEE
Transactions on Geoscience and Remote Sensing 42(6 ) 1149 ndash 1160
Segar D A (1998) Introduction to ocean sciences (No 55146 SEG)
Seidelmann P K Archinal B A Arsquohearn M F Conrad A Consolmagno G
J Hestroffer D amp Stooke P (2007) Report of the IAUIAG Working
Group on cartographic coordinates and rotational elements 2006 Celestial
Mechanics and Dynamical Astronomy 98(3) 155-180
Shone T (2000) GPS Water Level Measurements Final Report SSG2194
Presented at the EGS General AssemblyNice France
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
178
Shum C Yi Y Cheng K Kuo C Braun A Calmant S amp Chamber D
(2003) Calibration of Jason-1 altimeter over Lake Erie Marine Geodesy 26
335 ndash 354
Snider F G (2016) GPS Theory Practice and Applications Retrieved on
February 01 2016 from http wwwpdhcentercomcourses|116|
116contenthtml
Soares C G amp Carvalho A N (2012) Probability distributions of wave heights
and periods in combined sea-states measured off the Spanish coast Ocean
Engineering 52 13-21
Sontek (2015) Retrieved on August 24 2015 from
httpwwwsontekcomproductsdetailphpADP-Acoustic-Doppler-Profiler-4
Sorensen R M (2006) Basic Coastal Engineering Chapter 2 Two-Dimensional
Wave Equations and Wave Characteristics
Steele K E Chung-Chu T amp Wang D W C (1992) Wave Direction
Measurements using Pitch-Roll Buoys Ocean Engineering 19(4) 349 ndash 375
Stokes G G (1880) Theory of Oscillatory Waves Mathemathical and Physical
Papers 1 313 ndash 326
Taira K Saadon M N Kitagawa S amp Yanagi T (1996) Observation of
temperature and velocity in the coastal water off Kuala Terengganu Malaysia
Journal of Oceanography 52 251 - 257
Talley L D Pickard G L Emery W J amp Swift J H (2001) Descriptive
physical oceanography San Diego United State America Elsevier
Terada Y Kato T Itoh T Nagata S Fujita T Abe T Miyake T Nagai T
Koshimura S amp Miyazaki S (2003) A new tsunami detection system using
RTK-GPS in Ofunato city Proceeding of the IUGG 2003 Northeastern
Japan
Thurman H V amp Trujillo A P (2004) Introductory Oceanograpy 10th ed New
Jersey United State America Pearson Prentice Hall
Tolman H L (2008 May) Practical wind wave modeling In Proc CBMS Conf
Water Waves Theory and Experiment
Topper M B R (2013) Semantics of Spectral Density for Ocean Waves Institute
of Energy Systems Report The University of Edinburgh 1b
Torge W (2001) Geodesy Third completely revised and extended edition
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
179
Triaxys (2014) Triaxys Directional Wave Buoy Retreived on November 18
2014 from httpaxystechnologiescomtriaxys-wave-buoy-lp
Utusan Malaysia (2012) Hakisan pantai kian serius Utusan Melayu (M) Berhad
Vries J J Waldron J and Cunningham V (2003) Field tests of the new
Datawell DWR-G GPS wave buoy Sea Technology 44 50ndash55
WAFO (2000) WAFO - A Matlab Toolbox for Analysis of Random Waves and
Loads - A Tutorial Retreived from httpwwwmathslthsematstatwafo
Waseda T Sinchi M Kiyomatsu K Nishida T Takahashi S Asaumi S
Kawai Y Tamura H amp Miyazawa Y (2014) Deep water observations of
extreme waves with moored and free GPS buoys Ocean Dynamics 64 1269
ndash 1280
Watson C Coleman R amp Handsworth R (2008) Coastal tide gauge calibration
A case study at Macquarie Island using GPS buoy techniques Journal of
Coastal Research 24(4) 1071 ndash 1079
Watson C Coleman R White N Church J amp Govind R (2003) Absolute
calibration of TOPEXPoseidon and Jason-1 using GPS buoys in Bass Strait
Australia Marine Geodesy 26 285 ndash 304
Whitney M M amp Richard WG (2007) Estimating tidal current amplitudes
outside estuaries and characterizing the zone of estuarine tidal influence
Continental Shelf Research 28(3) 380 ndash 390
Williams S D P Bock Y Fang K P Jamason P Nikolaidis R M
Prawirodirdjo R M Miller M amp Johanson D J (2004) Error analysis of
continuous GPS position time series Journal of Geophysical Research
109(B3)
Wilson R M (2012) Archimedesrsquos principle get updated PhysicsToday 65(9)
15
Wire Mesh Machine (2014) Hot dipped wire galvanizing line Retrieved on
October 27 2014 from httpwwwchina-anbermachinecomHot-dipped-
wire-galvanizing-linehtml
Witte T H amp Wilson A M (2005) Accuracy of WAAS-enabled GPS for the
determination of position and speed over ground Journal of Biomechanics
38(8) 1717 ndash 1722
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154
180
Wu C Congwei H Zhihua L Yongqi C Xiaoli D Shan G amp Shengyue J
(2004) Kinematic GPS Precise Point Positioning for Sea Level Monitoring
with GPS Buoy Journal of Global Positioning Systems 3(2) 302 ndash 307
Xu G (2003) GPS Theory Algorithms and Applications 2nd ed Berlin
Germany Springer-Verlag
Yaakob O Zainudin N amp Shariff R 2004 Developing Malaysian Ocean Wave
Database Using Satellite Altimeter Proceeding of the Marine Technology
Conference (MARTEC 2004) Johor Malaysia
Yamaguchi I Kasai T Igawa H Harigae M Komori S Shigenaga T amp
Hosaka Y (2005) Ocean wave sensing system using point positioning GPS
receiver Proceeding in the Space Engineering Conference 14 29 ndash 34
Yang M amp Lo C F (2000) Real-Time Kinematic GPS Positioning for
Centimeter Level Ocean Surface Monitoring Proceeding of the National
Science Councils Republic of China 24(1) 79 ndash 85
Yoo Y Hou D Kouguchi N Ishida H Shiotani S amp Fujii H (2004)
Arrayed GPS-buoys wave observation system IEEE Techno Ocean 04 3
1370 ndash 1375
Young L E Wu S C amp Dixon T H (1986) Decimeter GPS positioning for
surface element of sea floor geodesy system Proceeding of the International
Symposium on Marine Positining Reston Virginia United State America
Zappa1 C J Banner M L Schultz Corrada-Emmanuel H A Wolff L B amp
Yalcin J (2008) Retrieval of short ocean wave slope using polarimetric
imaging Measurement Science and Technology 19(5)
Zhang Z Law C L amp Guanwan E (2007) Multipath mitigation technique
based on partial autocorrelation function Wireless Personal Communication
41 145 ndash 154