FIG 2011, Marrakech, 19 MAY 2011 1

Rui M. S. FERNANDESBarde JATAU

Ugochukwu EDOZIEDomingos ARMANDO

José JANUÁRIO

Rigorous Estimation of the Coordinates of two new National permanent GNSS networks in Africa:

NIGNET (Nigeria) and REPANGOL (Angola)

FIG 2011, Marrakech, 19 MAY 2011 2

Reasons to promote NIGNET and REPANGOL

- Adoption of a modern geodeticinfrastructure full compatible with theactual techniques of geo-referencing.

- Low quality of the existing network basedin observations carried out using oldtechniques.

- Lack of geodetic beacons with knowncoordinates in large areas of the country(destroyed or never implemented).

- Compatibility with the reference frames ofneighboring countries through thecollaboration with international projects,namely AFREF and IGS.

FIG 2011, Marrakech, 19 MAY 2011 3

NIGNET

11 stations installed until 2010 2 stations installed in 2011

FIG 2011, Marrakech, 19 MAY 2011 4

REPANGOL

18 Stationsone per capital of province

FIG 2011, Marrakech, 19 MAY 2011

Installed Systems

5

a) GNSS System –Nigeria: Trimble NetR8 and NetR9.Angola: Topcon NetG3A

b) Router –communications based on mobile networks (GPRSand 3G). Software developed by SEGAL using VPNs(Virtual Private Network).

c) Power Management –Solar panels are used to supply all the necessarypower.In Angola, the streaming of RTK corrections ispossible when there is power from the electrical grid(or using an additional battery).

FIG 2011, Marrakech, 19 MAY 2011 6

NIGNET stations – Examples

• State-of-art Receiver+Antenna

• Mobile Communications

• Powered by Panel Solars

FIG 2011, Marrakech, 19 MAY 2011 7

NIGNET stations – Examples

Toro

Exposed Rock

FIG 2011, Marrakech, 19 MAY 2011

REPANGOLOndjiva

8

FIG 2011, Marrakech, 19 MAY 2011

REPANGOLCuíto

9

FIG 2011, Marrakech, 19 MAY 2011 10

Methodology GIPSY

Processing...

GIPSY (strategy PPP)Day 1

Solution 1

Day n

Solution n

ITRF2008 Coordinates day 1

GIPSY toolsGlobal Parameters

(Dedicated Mapping)

ITRF2008 Coordinates day n

Combined Solution ITRF2008

GIPSY toolsand SEGAL applications

n=7

FIG 2011, Marrakech, 19 MAY 2011 11

NIGNET - r.m.s. repeatabilitiesWeekly Solutions

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

ABUZ (46) BKFP (43) CGGT (43) FUTY (53) GEMB (8) OSGF (51) RUST (44) ULAG (49) UNEC (43)

North

East

Vertical

mm (number of weeks used between brackets)

FIG 2011, Marrakech, 19 MAY 2011 12

r.m.s. repeatabilitiesWeekly Solutions

FIG 2011, Marrakech, 19 MAY 2011 13

r.m.s. repeatabilitiesWeekly Solutions

FIG 2011, Marrakech, 19 MAY 2011 14

r.m.s. repeatabilitiesWeekly Solutions

Weeks with more than 10 weeks selected

Weeks with all stations available

Selected week to compute thesolution wrtITRF2008

FIG 2011, Marrakech, 19 MAY 2011 15

Questions?