GALILEO POSITIONING EVOLUTION - orbi.uliege.be · Galileo signals vs GPS signals • SPP : still affected by Galileo low number of satellites (higher PDOP than GPS) Quality of positioning

GALILEO: POSITIONING EVOLUTION

Deprez CécilePhD CandidateUniversity of Liège

2005 - 2008DEVELOPMENT

SYSTEM TESTED

GIOVE A – B

2013IN-ORBIT

VALIDATION PHASE

4 IOV satellitesInitial ground infrastructure

ESA imagesESA images

2016INITIAL GALILEO

SERVICES

OS, SAR, PRS, CS demonstration

GSA image

2014 - 19DEPLOYMENT PHASE

FOC system deployment

2020FULL OPERATIONAL CAPABILITY

24 operational satellites+

6 spares satellites +

Complete ground infrastructure

ESA images

ESA images

IOV FOCTEST PROTOTYPES

GIOVE-B

30

25

20

5

0

15

10

EVOLUTION OF # SATELLITES

201120082005 2012 2014 2015 2016 2017 2018

GIOVE-A

2006 2007 2009 2010 2013

4 satellites = positioning possible

24 4

6

12

18

22

26

AM/FM GIS Belux & Flagis 25/10/2018 - Cécile Deprez, ULiège [email protected]

FOC

E7 -

E3

E4 -

E5

FOC

E21

–E2

5

E27

–E3

1

Posi

tio

nin

g n

on

ava

ilab

le

FOC

E36

E1

5 –

E33


2014

Elev min: 0°

December 10, 2014

0

Observation duration: 24h

Mean # of satellites: 11

GPS

Observation duration: 1h56

Mean # of satellites: 4

Galileo

24 hours of data

16

14

12

10

8

6

4

2

0

# sa

telli

tes

5 visible satellites



Mean # of satellites: 4.2

Galileo

2015

Elev min: 0°

December 27, 2015

0



GPS

24 hours of data

16

14

12

10

8

6

4

2

0

# sa

telli

tes



2016

Elev min: 0°



December 1, 2016GPS



Galileo

024 hours of data

16

14

12

10

8

6

4

2

0

# sa

telli

tes



2017

Elev min: 0°

November 16, 2017

0



GPS



Galileo

24 hours of data

16

14

12

10

8

6

4

2

0

# sa

telli

tes



2018

Elev min: 0°

October 15, 2018



GPS



Galileo

24 hours of data

16

14

12

10

8

6

4

2

0

# sa

telli

tes



Observation duration improvement over years

Ho

urs

Summary:

1.93.4

18.9

22.224


24 visible satellites : 24h observation!

2018 conclusions :

Average # visible satellites/day : 7.4

• Min # visible satellites : 5

• Max # visible satellites : 10[GPS : 16]

[GPS : 7]

Positioning with Galileo-only possible anytime during the day

Observation durationH

ou

rs

[GPS : 11.3]


Evolution of the mean # satellites visible/day over 10 days in 2018:

Days of Year 2018

# sa

telli

tes

Mean: 7.27

Galileo = 10 days periodicity


30

25

20

5

0

15

10

EVOLUTION OF GEOMETRY [PDOP]

2014 2015 2016 2017 2018

PDOP # sat

Increase in # satellites improves geometry

Precision of positioning improved : .POS OBS DOP


Galileo E1 Galileo E5a Galileo E5b Galileo E5a+b

Galileo E6

SignalsAll users


Signal quality :

Cen

tim

etre

s

Codes

GPS

Galileo

L1 L5 L2


Short baseline (5.6 m)between two Septentrio X4connected to two choke ring Trimble antennas

Signal quality :

Mill

imet

res

GPS

Galileo

Phases

L1 L5 L2


Short baseline (5.6 m)between two Septentrio X4connected to two choke ring Trimble antennas

Positioning techniques

Codes Phases

One receiverSingle Point

Positioning (SPP)Precise Point

Positioning (PPP)

Expected 3D precision ~ 5-20 m ~ 0.01 m

Two receivers DGNSS (DGPS)Real Time Kinematic

(RTK)

Expected 3D precision ~ 1-3 m ~ 0.10 m

Values given in reference to ellipsoid WGS84


Short baseline (5.6 m)between two Trimble NetR9connected to two choke ring Trimble antennas

Positioning with Galileo SPP

Galileo E1:

Galileo E1Position 3D: 10.79 m




Satellite Galileo E24 degrades positioning with Galileo!


Galileo E1:


Satellite Galileo E24 removed !


Positioning with GPS SPP

Galileo E1:


GPS L1Position 3D: 4.33 mGPS L1:


Positioning with Galileo + GPS SPP

Galileo E1+

GPS L1 :

Galileo E1 +

GPS L1

Position 3D: 3.32 m

Satellite Galileo E24 removed !


SPP

Galileo E1 +

GPS L1

Position 3D: 6.12 m

SPP DGPS

1 m1 m


DGPSPositioning with Galileo

1 m

Galileo E1:

Galileo E1Position 2D: 0.72 mPosition 3D: 1.13 m



Galileo E1:



Satellite Galileo E24 removed


Galileo E1:

Galileo E5aPosition 2D: 0.55 mPosition 3D: 0.86 m

Galileo E5a:





Galileo E1:

Galileo E5a+bPosition 2D: 0.16 mPosition 3D: 0.25 m

Galileo E5a+b:




DGPS

Galileo E1:

GPS L1Position 2D: 0.81 mPosition 3D: 1.32 m


Positioning with GPS

GPS L1:


DGPSPositioning with Galileo + GPS

Galileo E1+

GPS L1 :

Galileo E1 +

GPS L1

Position 2D: 0.43 mPosition 3D: 0.85 m



DGPSPositioning with Galileo + GPS

Galileo E5a+

GPS L5 :

Galileo E5a +

GPS L5




RTKDGPS RTK

1 m 1 m


Positioning with Galileo RTK

1 m


Galileo E1:



Positioning with Galileo RTK

Galileo E5:Galileo E5a+bPosition 2D: 0.26 mPosition 3D: 0.33 m

Galileo E5a+b:


Galileo E1:



Positioning with GPS RTK


Galileo E1:

GPS L1Position 2D: 0.17 mPosition 3D: 0.22 m

GPS L1:


Positioning with Galileo + GPS RTK

Galileo E1+

GPS L1 :

Galileo E1 +

GPS L1




Positioning with Galileo possible all day

CONCLUSIONS

Galileo signals vs GPS signals

• SPP : still affected by Galileo low number of satellites (higher PDOP than GPS)

Quality of positioning with Galileo-only

• Similar precisions for codes and phases

• Code signal Galileo E5a+b exceptional

• DGPS : Similar values of accuracy for both GPS & Galileo

• RTK: Similar values of accuracy for both GPS & Galileo

GPS + Galileo combination improves both GPS-only and Galileo-only solutionsAM/FM GIS Belux & Flagis 25/10/2018 - Cécile Deprez, ULiège -

[email protected]

Cécile DeprezDoctorante en GNSS et géodésieUnité de Géomatique - Université de Liège

Phone : +32 4 366 58 80Email: [email protected]

CONTACT


mailto:[email protected]

https://www.linkedin.com/in/cecile-deprez/

GALILEO POSITIONING EVOLUTION - orbi.uliege.be · Galileo signals vs GPS signals • SPP : still affected by Galileo low number of satellites (higher PDOP than GPS) Quality of positioning

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