1

CORS DiscussionIstanbul Kültür Üniversitesi

18.5.2007Yurtdisindan Örnekler

Gottfried KonecnyLeibniz University Hannover

Contents:

1. GPS technology (established since 1985),accuracy impovement by DGPS (post processing)and by CORS (in real time)

2. Consequences in Europe (EUREF campaigns,ETRS 89, national reference systems, GPS & Glonass & Galileo = GNSS)

3 3D height reference (GNSS leveling and gravity;3. 3D height reference (GNSS, leveling and gravity;geoid calculation)

4. Example Serbia

5. Example Germany (Baden Württemberg)

2

1.GPS Technology

known since 1985

3

4

GNSS basic principle

Z

R 1

R 2 R 3

R 4

P P D O P l

XY

Z

WGS84based on mass centered ellipsoid determined by the worldwide IGS network

5

GNSS Error Sources

Satellite ClockSatellite Orbit

Ionospheric DelayIonospheric Delay

Tropospheric Delay

Antenna Phase Center

XY

Z

WGS84

Receiver ClockMultipath

Antenna Phase Center

Magnitude of Error Sources

Error source Absolute influence Relative influence

Satellite Orbit 2 ... 50 m 0.1 ... 2 ppmSatellite Clock 2 ... 100 m 0.0 ppmIonosphere 0.5 ... >100 m 1 ... 50 ppmTroposphere 0.01 ... 0.5 m 0 ... 3 ppmMultipath Code m mM lti th Ph

High spatial correlation

Multipath Phase mm ... cm mm ... cmAntenna mm ... cm mm ... cm

Local (Calibration)

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GNSMART Results: Lower Saxony

P iti APosition Accuracy

© 2000 Ge o++® Ge sel lschaft für sate ll itenge stü t zte geodä tische und na vi gatorisc he Te chnol ogie n mbH, D-30827 Garbsen. Steinri ede 8, Te l. (05131) 4689-0, Fax (05131) 4689-99 Web: www. ge opp.de, E-mai l:i nfo@ge opp.de

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Time To Fix Ambigities

Alternatives:

- Use of CORS Stations every 50 km for 1cm accuracy

- Use of CORS Stations every 100 km for 2 to 3cm accuracy

- Use of CORS Stations every 500km for dm to m accuracy

- Transmission of corrections via- Transmission of corrections via- Internet (offline for post processing)- GSM (if net exists)- Al Thuraya satellite

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National Reference Systems

• National Mapping Agencies in charge• Established by traditional methods :

– Fundamental Point lat & long by astro obs.– Fundamental Azimuth– Triangulation & Net Adjustment

Densification from 1st to 4th order– Densification from 1st to 4th order– result: national reference on best fitting

ellipsoid

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Map Projections

• Each chosen reference ellipsoid, defined b l t &l f th f d t l i t dby lat &long of the fundamental point and the fundamental azimuth, is projected onto a plane or a surface unrollable onto a plane

• Exact mathematical relations exist for theExact mathematical relations exist for the transformation & vice versa

• examples: UTM, 3°Transverse Mercator, Lambert applicable in different zones

European Spatial Reference Systems –Basis for a European Spatial Data Infrastructure (ESDI)

Milestones/Actions:• IAG SC 1.3a EUREF: TWG (since 1987), ETRS 89

• CERCO WG 8 Geodesy, 2001 EuroGeographics ExGG Geodesy

• European geodetic networks: GPS campaigns (1988), UELN (1994), EPN (1995), EUVN (1997), ECGN (2003)

• Standardisation 1994 to 2003: CEN/TC 287, ISO/TC211 (ISO 19111)

• Series of EC workshops: Spatial Reference Workshop 1999, Map Projection Workshop 2000, EuroGrid Workshop 2003, Workshop on vertical reference systems in Europe in April 2004

•INSPIRE/EuroSpec (Infrastructure for Spatial Information in Europe Initiative in 2001)

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EUREF GPS campaigns

1988 – 1999

(1 cm accuracy)

Bulgaria

Romania

NGK

EUREF GPS Permanent Network EPN EPN Analysis and Data Centers

BEK

BKG

WUT

GOP

SGO

IGN

ROB

DEO

# stations:

Local Analysis Center Regional Data Center Local Data Center

LPT

OLG

UPA

ASI

COE

IGE

153 total48 IGS

15 AC

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N ti l C di t R f S t (CRS)

Pick a country in the list or a red dot in the map, then you can get at the next page the information aboutthe Coordinate Reference Systems CRS and the Transformations to ETRS89 for the country:

a ona oor na e e erence ys emsof European Countries and

Transformations to European Terrestrial Reference System ETRS89

   

   

   

   

   

   

   

   

   

   

   

   

Luxembourg

Latvia

Ireland

Hungary

Great Britain

Germany

Finland

Denmark

Cyprus

Bulgaria

Austria

Lithuania

Italy

Iceland

Greece

Gibraltar

France

Estonia

Czech Republic

Croatia

Belgium

Albania

SWEDEN

   

   

   

   

   

   

   

   

 

       |  |  |  |  |

Copyright by BKG 2001 Last Update 20. April 2001

oHome Content European CRS National CRS C ntact Reference

Turkey

Sweden

Slovenia

Russia

Portugal

Norway

Netherlands

Ukraine

Switzerland

Spain

Slovak Republic

Romania

Poland

Northern Ireland

Macedonia

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2. European Terrestrial Reference System 1989 (ETRS89) and its use in Europe

• The European Continental Plate is moving quite uniformly some3 cm per year, relatively to the ITRS. Excepted is the south-eastern extreme of Europe (Greece, Turkey).eastern extreme of Europe (Greece, Turkey).

• The IAG Sub-commission for Europe EUREF decided to define aSystem fixed to the European plate in order to have stable co-ordinates for Europe.

• This System (datum) is named ETRS, or ETRS89, identical to theITRS in the year 1989.

• Since 1989, ETRS89 coordinates have shifted from their valuesSince 1989, ETRS89 coordinates have shifted from their valuesexpressed in ITRS. The shifts are monitored by IERS and EUREF.

• This shift is well known, and transformations from one to theother are possible for most parts with a 1 cm accuracy. The shiftparameters are given with the ITRF solutions.

Developments• Continuous extension of the tracking network EPN

(east of Europe and special interests, e.g. tide gauges)

• Integration of special projects (e.g. EUREF’s ECGN, IGS TIGA-PP)

• Standards for EPN densification e.g. establishment of EUREF-IP broadcaster (NTRIP)

• Development of web-portal for users especially of th GIS itthe GIS community

• Preparation of GALILEO positioning technologies

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EUREF/EuroGeographic vision for a structure of positioning services with different accuracy levels for the realization of a European spatiallevels for the realization of a European spatial data infrastructure (ESDI):

• m real time, in future covered by GNSS infrastructure

• dm real time terr differential GNSS (EPN NTRIP)• dm real time, terr. differential GNSS (EPN, NTRIP)

• cm post processing, terr. differential GNSS (EPN),

real time standards (EPN, densification networks e.g. GREF and EUPOS, NTRIP)

United European Levelling Network (UELN) status 2003

Realization of theRealization of the

vertical reference

in Europe better than 1 dm

Vertical datum:Normaals Amsterdams P ilPeil

Heights:Geopotential numbers

Normal heights

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European Vertical Reference Network (EUVN)

Integrated network with 200 stations (35 IGS stations, 70 tide stations)

-Unificationof national height systems-Connection of European seas

Concept (static):-Position X (ITRS, ETRS89)-Height cp, W (UELN 94/98)-Gravity g (IGSN 71)

}P(X,W

-Sea surface

GPS Connections - EUREF

• Points of EUREF networknetwork– Method: GPS– Session: 5 days– Number of points: 8– Distance: 160 km– Accuracy: 5 mmAccuracy: 5 mm

• SREF linked on EUREF

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GPS Referent network - SREF

• Points of SREF networknetwork– Method: GPS– Session: 90 min– Number of points: 841– Distance: 10 km– Accuracy: 10 mmAccuracy: 10 mm

• Finished August 2002.

GPS Permanent stations

• Permanent stationsNumber of stations– Number of stations 30+4

– Accuracy 10 mm– Distance 70 km– All Serbia covered

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GPS Aims of the project

• Creation referent system of the Republic f S biof Serbia

• Positioning for creating of the Real Estate Cadastre

• Positioning all kinds of topographic-cartographic basescartographic bases

• Navigation of the public service's

Cost of project

• Permanent stationsEquipment: 1 120 000 GSM– Equipment: 1.120.000 €

– Software: 180.000 €RGZ (GGA)

– Total: 1.300.000 €

GSM

Radio

Internet

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1975 2005

The example of the State of Baden-Württemberg

- reduction of the personnel cost -

Number of

employed workers

(present cost-output evaluation)

128

4,96 Mio Euro 0,96 Mio Euro

24

Personal expenditure

)

Annual savings 80,7% = 4,0 Mio Euro

GPS, GLONASS, Galileo

The technical changes in surveying and mapping

- A look back over the last 20 years -

On the basis of GNSS-technology a new type of surveying has been developed in connection with extensive hard- and software

Standardization for the international terrestrial reference system

Replacing of the traditional national spatial reference systems

National GNSS based reference station networks have been set upSAPOS®, swipos, APOS,

Replacing of the traditional national spatial reference systemsDHDN ETRS89 GNSS-based surveying online without identical

pointsReduction of the survey standards in the official surveying and

mapping

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Reference station networks realize the spatial reference system as a

The technical changes in surveying and mapping

- The effects of the technical changes -

In future we will work only with general control networks which arethinned out

• Position• Height• Gravity

The previous 1d- rather 2d-general control networks will be replaced by

whole

replaced by 3d- to 5d-general control networks

Through the combination of levelling and GPS-derived heights we are in a

position to create a new type of height surveyance

Homogenous federal general control networks (duty)SAPOS® f t ti f th t ETRS89

The situation in the Federal Republic of Germany- Decision of the AdV in the year 2004-

SAPOS® reference stations of the system ETRS89

Geodetic contol points - 3d-station monumenting- 3d-coordinates in the system ETRS89/UTM - Heights in the system DHHN92- Gravity in the system DHSN96

Height general control network of 1. order in the system DHHN92General gravity points of the DHSN 1. order in the system DHSN96

State specific general control networks (option)Position general control networks 1. to 4. order in the system of GKHeight general control networks 2. and 3. order in the system DHHN92Gravity general control networks 2. and 3. order in the system DHSN96

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Geodetic contol point represents a 5d-point

The situation in the Federal Republic of Germany- Function of the geodetic control point -

- 3d (coordinates x,y,z in the system ETRS89 / UTM)

- 1d (height in the system DHHN92)- 1d (gravity in the system DHSN96)

Geodetic control points serve

link of position height and gravity concisely in one point

for a short time

realization of the total spatial reference

- link of position, height and gravity concisely in one point- additional group of points

in the long run

Now Future

16-Homogenous federal general control networks (duty)

SAPOS®-reference stations of the system ETRS89

The example of the State of Baden-Württemberg - Reduction of points-

180

9 000

36

9 00036

-

State specific general control networks (option)

Geodetic contol points - 3d-station monumenting- 3d-coordinates in the system ETRS89/UTM - Heights in the system DHHN92- Gravity in the system DHSN96

Height general control points of 1. order in the system DHHN92General gravity points of the DHSN 1. order in the system DHSN96

61 000

Total

6 00052 000 14 000

-

-

128 000 24 000

State specific general control networks (option)Position general control networks 1. to 4. order i.t.s.o. Gauss-KrügerHeight general control networks 2. and 3. order i.t.s.o. DHHN92Gravity general control networks 2. and 3. order i.t.s.o. DHSN96

ca.

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Accuracy of the points : +/- 2 cm

The situation in the Federal Republic of Germany- Reason for the reduction of the general control network -

Position3d

Height

SAPOS reference stations in connection with software for networkingReduction: up to now: 1...2 points per 1 km²

in future: 1 point per 2000...2500 km²

Clear separation between the scientific network and the use network

Use network has to accept a reduction of the survey standard

Networks of the 2. ...3. order will be dropped

GravityFrame network as a scientific network will be required

Non-marked out general gravity control network of 2. and 3. order for the determination of the highly accurate Quasigeoid

The situation in the Federal Republic of Germany

- Reason for the reduction of the general control network

Important assumptionsnetwork -

In the long run we have to give up the existing controlnetworks

We have to accept, that GNSS-technology is the technology of the futureof the future

GNSS-technology is no additional technology to the existing technology

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Setup of an own Satellite Positioning Service

The situation in the Federal Republic of Germany - The future general control network for a state -

Accuracy of +/- 2 cm for the fixing of a point

Geodetic control point

Absolute measurement of gravity should be carried outFairly identic to the levelling network of 1. orderFairly identic to the points of the Satellite Positioning Service

1 reference station per 2 500 km²All reference stations have to be connected by software for networking

Levelling networkLevelling network 1.order has to be seen as a scientific network

Recovered through a highly accurate Geoid (better +/- 1 cm)Use network has less accuracy (+/- 2 cm)

Federal Republic ofGermany

State of Baden-WürttembergState X

The future general control network for a state- Theoretical thoughts of an outsider -

Area 35 500 km²x 000 km²

Geodetic control points

260 pointsGNSS-reference-stations

260 points

Levelling network

Gravity network, markedt k d

55 000 points

16 points

200 00 i t

0,45x points

200,00x points 7 100 points

200,00x points 55 000 points

357 023 km²

16 500 i t

16 points

7 100 points7 100 i t

0,45x points

not marked

Total, markednot marked

200,00x points

200,45x points200,00x points

All together 400,45x points

7 100 points7 016 points

14 116 points

55 260 points

71 760 points

16 500 points

16 500 points

7 100 points

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Federal Republic ofGermany

State of Baden-WürttembergState X

The future general control network for a state- Reality -

Area 35 500 km²x 000 km²

Geodetic control points

260 pointsGNSS-reference-stations

(260+x) points

Levelling network

Gravity network, markedt k d

55 000 points

16 points

200 00 i t

0,45x points

200,00x points 23 000 points

200,00x points 55 000 points

357 023 km²

70 000 i t

180 points

7 100 points4 000 i t

0,45x points

160

160

71 400

71 400

16

16

7 100

7 100not marked

Total, markednot marked

200,00x points

200,45x points200,00x points

All together 400,45xpoints

4 000 points23 196 points

27 196

55 260 points

125 260+x

70 000 points

70 000 points

4 000 points71 400

71 56071 400

142 960

7 100

7 1007 016

14 116

Condition: Spatial reference of cadastre

The effects on the real estate cadastre

Measurements of cadastre through SAPOS® reference stations automatically show the coordinates of the target system

is identic to thespatial reference of the general control network

Usual fitting into surrounding cadastre field can be left out

Reference stations will directly show the spatial reference

Expenditure of the surveying the real estate will be reduced by factor 3 to 5

Expense and personal expenditure will fall accordingly

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Summary

1 Technical changes and their results in surveying and mapping

Radical change to a modern general control network

1. Technical changes and their results in surveying and mapping

2. Situation in the Federal Republic of Germany• German strategy for the future general control network• Function of the fundamental geodetic points

3. Example of the State of Baden-Württemberg• General control network of the future • Potential for cost savingg

5. How modern new general control network affect the real estate cadastre?

4. Theoretical concept for a future general control network of a state

1975 2005

The example of the State of Baden-Württemberg- Reduction of the personal expenditure -

Number of

employed workers

(present cost-output evaluation)

128

4,96 Mio Euro 0,96 Mio Euro

24

Personal expenditure

)

Annual savings 80,7% = 4,0 Mio Euro

24

Overview

C fGuarantee

Core tasks of the state

Responsibility

Structure

Activation

16 federal states

Surveying, mapping and cadastre authoritiesLicensed surveyors

Specialists

Coordination

y

33.000

AdV

2

Tasks

Map (ALK)R i t (ALB)Real estate cadastre

State survey

Register (ALB)Integrated system (ALKIS®)

Reference systems3D-Basic networkPositioning (SAPOS®)Geotopography (ATKIS®)

(AFIS®)

Geospatial reference information system

AAA-data modellGIS-standards (ISO, OGC)

3