Post on 24-Jun-2018
THE SATELLITE BASED AUGMENTATION SYSTEMS SBAS FOCUSING ON EGNOS AND ITS
PERFORMANCE IN EGYPT
DR. MOHAMED MOHASSEBEGYPTIAN NAVY
DR. REFAAT RASHADARAB INSTITUTE OF NAVIGATION
MOSTAFA MAHMOUDEGYPTIAN NAVY
AIM
The AIM of this research is evaluate the EGNOS (European Geostationary Navigation Overlay Service) positioning
accuracy in North of Egypt compared with the accuracy of GPS and DGPS positioning
Free GPS Augmentation
Satellite Based Augmentation Systems
WAAS EGNOS GAGAN MSAS
EGNOS Design
6 NLES (Navigation Land Earth Stations)
34 RIMS (Ranging and Integrity Monitoring Stations)
4 MCC (Mission Control Centers)
DGPS
EGYPT
Field Test
Four GPS Receivers
AshtechSea side
AshtechLand side
Magellan Leica
Field Test
Four GPS Receivers
Field Test
Stage I
Pseudorange measurements
Field Test
Stage I
AshtechSea side
AshtechLand side
Magellan Leica
Field Test
Stage II
NMEA 183 GGA message
Stand alone Stand aloneEGNOS DGPS
Position Accuracy
Stand alone
Land side
Position Accuracy
Stand alone
Position Accuracy
Stand alone
Lat Long Position
Min 0 0 0.11
Max 10.15 5.81 10.94
Standard Dev 1.425 0.831 1.422
CEP 50% 2.528 1.474 2.52
CEP 95% 3.49 2.05 3.48
Position Accuracy
DGPS
Position Accuracy
DGPS
Position Accuracy
DGPS
Lat Long Position
Min 0 0 0.1
Max 3.24 3.12 3.68
Standard Dev 0.52 0.45 0.56
CEP 50% 0.93 0.81 0.99
CEP 95% 1.29 1.12 1.37
Position Accuracy
EGNOS
Position Accuracy
EGNOS
Position Accuracy
EGNOS
Lat Long Position
Min 0 0 0.1
Max 5.34 3.34 6.3
Standard Dev 1.05 0.51 0.99
CEP 50% 1.86 0.91 1.75
CEP 95% 2.58 1.26 2.42
The shape of the scatter plot between the standalone GPS and EGNOS are similar. On the other hand, EGNOS has the smaller errors
standalone GPS and EGNOS scatter plot
Comparison
The uncertainty for the DGPS is the best between all systems, according to the Figures which compare the DGPS with EGNOS.
EGNOS and DGPS scatter plot
Comparison
0
0.5
1
1.5
2
2.5
3
3.5
4
Landside GPS
Seaside GPS DGPS EGNOS Landside GPS
Seaside GPS DGPS EGNOS Landside GPS
Seaside GPS DGPS EGNOS
POS LAT LONG
95%
Ho
rizo
nta
l p
osi
tio
n a
ccu
racy
(m
)
The GPS, DGPS, and EGNOS 95% horizontal position accuracy for 24 hours observations
Conclusions
Most of the errors in all systems are in the south direction, because there is no satellites pass in the north bearing
The satellites almanac during the observation time
Position Spike
Future Work