uts:faculty of engineering and it international leaders in practice-based education the 16th...
TRANSCRIPT
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
The 16th Asia-Pacific Conference on Communications31 Oct. - 3 Nov. 2010, Auckland, New Zealand Page 1
Dr Xiaoying KongUniversity of Technologies, Sydney. Australia
Dr Li LiuThe University of Sydney, Australia
Dr Tich Phuoc TranUniversity of Technologies, Sydney. Australia
Modeling Satellite Positioning Errors in Different Configurations
from End User's Viewpoint
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Global Navigation Satellite Systems (GNSS)
• Global Navigation Satellite Systems – Positioning, navigation, & timing data
• Global Positioning System (GPS)• Russian - GLONASS• European Union- Galileo satellite system• China - Beidou• Japan - Quasi-Zenith Satellite System (QZSS)
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 2
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
GNSS Errors
• Global Navigation Satellite Systems provide services to global end users with high quality positioning data but with errors.– Selective availability (SA), satellite ephemeris
errors, satellite geometry, multipath effect, atmospheric effects, clock inaccuracies, …
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 3
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
DGPS, WAAS- improving positioning accuracy
• Differential GPS (DGPS)• uses fixed ground stations to correct stand-alone GPS.
• Wide Area Augmentation System (WAAS)• consists of ground stations and reference stations, which
collect, calculate and transmit correction data
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 4
• When fixed ground station signals are unavailable
Land navigations, air navigations and robot positioning need to rely on stand-alone GPS
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
improving positioning accuracy• Most efforts
– understanding the characteristics of GPS error sources • modeling multipath effects • modeling ionospheric effects • …
• “white-box approach”
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 5
????
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
• Our approach • “Black-box approach”
– End user’s view point
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 6
improving positioning accuracy
input output
outputinput
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Black box model- our approach
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 7
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
2 phases - our approach
• Configuration I
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 8
Positioning error modeling
Using PSD
Positioning error de-correlation
• Configuration II 2000 2010
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Phase I - Error models
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 9
• Configuration I
22 2
)()(
kss
srsTranFn I
• Configuration II
ssTranFn II
)(
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Phase II – de-correlation
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 10
• Aiding sensor – inertial measurement sensors • Integrated positioning system
• Shaping filter• Configuration I
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Model - Configuration I
Xiaoying Kong UTS:FEIT:CRIN Page 11
• Process model
• Observation model
)(
)(
0
0
01
00
)(
)(
)(
)(
000
1200
0000
0010
)(
)(
)(
)(
2
tw
tw
r
r
tX
tX
tdv
tdr
k
tX
tX
tvd
trd
sp
ins
ss
s
ss
s
)()()( tvtxHtz f
0101fH
A
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Phase II – de-correlation
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 12
• Shaping filter
• Configuration II
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Model - Configuration II
Xiaoying Kong UTS:FEIT:CRIN Page 13
gps
imu
hphp S
dV
dR
S
Vd
Rd
X
0
0
0
1
0
000
000
010
gps
hpS
dV
dR
Z
]101[
• Process model
• Observation model
A
H
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Phase II – de-correlation
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 14
• Configuration II
frequency domain
timedomain
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Conclusions
• Black box approach, from end user’s view point• Investigate the external behaviors• No efforts on modeling many individual error
sources and receiver noises• Accuracy improved
• Can be applied in the situations – when satellite configurations and receiver change
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 15
UTS:Faculty of Engineering and ITInternational Leaders in Practice-Based Education
Thank you
APCC 2010Modeling Satellite Positioning Errors in Different Configurations from End User's Viewpoint Page 16
Questions?