Relative positioning with Galileo E5 AltBOC code measurements, the winning entry in the CLGE Students’ Contest 2016, by Cécile Deprez, University of Liège

1. Cécile Deprez
PhD Candidate
University of Liège
Relative positioning with Galileo
E5 AltBOC code measurements
The CLGE Students’ Contest 2016

2. Possibility of precise positioning with ANDROID raw code pseudoranges ?
Google opens up
The CLGE Student's Contest 2016 - C.Deprez
code measurements access

3. Metres
 Expected precision on a position :
Codes
Challenge
The CLGE Student's Contest 2016 - C.Deprez

4. Decimetres
 Required precision on a position :
Mass-market applications
Challenge
The CLGE Student's Contest 2016 - C.Deprez

5. Hypothesis
Galileo E5 signal
AltBOC Modulation
 High tracking accuracy
 Strong multipath
resistance
Improvement of the code pseudorange precisions
The CLGE Student's Contest 2016 - C.Deprez

6. Method
Double difference :
Difference between two SIMULTANEOUS receiver
observations of the two same satellites
Relative Positioning
The CLGE Student's Contest 2016 - C.Deprez

7. Configurations
ZERO BASELINE
SHORT BASELINE
MEDIUM BASELINE
Receiver
observation noise
Theoretical case
Baseline length: 0 metre
Not used in practice
Estimation of the observation noise of the receiver
The CLGE Student's Contest 2016 - C.Deprez

8. Configurations
ZERO BASELINE
SHORT BASELINE
MEDIUM BASELINE
Analytical case
Baseline length: 5 metres
Estimation of the precision of the OBSERVATIONS
Multipath
+
Noise
The CLGE Student's Contest 2016 - C.Deprez

9. Configurations
ZERO BASELINE
SHORT BASELINE
MEDIUM BASELINE
Practical case
Baseline length:
23 kilometres (Liège – Waremme)
87 kilometres (Liège – Brussels)
Precision of the POSITIONS
Atmospheric errors
+
Multipath
+
Noise
The CLGE Student's Contest 2016 - C.Deprez

10. Equipment
Waremme
Brussels
Septentrio PolaRx4TR
Septentrio PolaRx4
The CLGE Student's Contest 2016 - C.Deprez
University of Liège
Trimble Septentrio
R9R9 xSx5 x4x4

11. Observable precisions (metres)
10 Days in June 2016
L1 L2 L5 E1 E5a E5b
Trimble 0.38 0.30 0.30 0.24 0.22 0.24
Septentrio 0.20 0.12 0.14 0.17 0.14 0.14
E5 AltBOC
0.14
0.06
GPS Galileo
Short baselines in Liège
The CLGE Student's Contest 2016 - C.Deprez

12. Results
Observable precision
CONCLUSIONS
Different precisions for different types of receivers
Galileo E5 AltBOC outperforms other GPS and Galileo signals
Galileo E1 & GPS L1 show the worst precision values
Galileo signals are more precise than GPS signals
GPS L2/ GPS L5, Galileo E5a/Galileo E5b show similar quality
The CLGE Student's Contest 2016 - C.Deprez

13. Precision of the positions (metres)
Liège
5 metres baseline
17th January 2016
RMSE 3D
0.53 metres
Galileo E5 AltBOC
The CLGE Student's Contest 2016 - C.Deprez

14. Precision of the positions (metres)
Waremme
23 kilometres baseline
1st April 2015
RMSE 3D
0.59 metres
Galileo E5 AltBOC
The CLGE Student's Contest 2016 - C.Deprez

15. Precision of the positions (metres)
Brussels
87 kilometres baseline
RMSE 3D
1.68 metres
Galileo E5 AltBOC
The CLGE Student's Contest 2016 - C.Deprez
1st April 2015

16. Conclusions
POSITION precisions
Galileo signals show a better precision than GPS signals
Galileo E5 AltBOC is superior to other signals
OBSERVATION precisions
The CLGE Student's Contest 2016 - C.Deprez

17. Conclusions
POSITION precisions
OBSERVATION precisions
Limited number of available Galileo satellites degrades the solution
Days with good satellite visibility allow reaching few decimetres
precision For baselines from 5 metres to 23 kilometres
When compared to reduced-GPS constellation, Galileo
results are very promising
The CLGE Student's Contest 2016 - C.Deprez

18. The CLGE Student's Contest 2016 - C.Deprez
Dissertation submitted in 2015 to
the University of Liège in partial
requirements for the degree of
Master of Geomatics and
Geometrology
Under the supervision of Pr. René Warnant, University of Liège
Contact: rene.warnant@ulg.ac.be
The CLGE Students’ Contest 2016Cécile Deprez, University of Liège
Contact: cecile.deprez@ulg.ac.be