1. KARTDATA TIL NYTTE FOR SAMFUNNET POSITIONING DATA – FOR SOCIETY’S BENEFIT DETERMINATION OF THE GRAVITY FIELD OVER NORWEGIAN TERRITORIES

2. KARTDATA TIL NYTTE FOR SAMFUNNET GRAVNOR: DETERMINATION OF THE GRAVITY FIELD OVER NORWEGIAN TERRITORIES USING GOCE DATA AND SPACE GEODESY SOFTWARE GEOSAT E. Mysen (Norwegian Mapping Authority, NMA) P.H. Andersen (Norwegian Defence Research Establishment, NDRE) POSITIONING DATA – FOR SOCIETY’S BENEFIT

3. KARTDATA TIL NYTTE FOR SAMFUNNET SPACE GEODESY SOFTWARE GEOSAT  25 years at Norwegian Defence Research Establishment  GPS, VLBI, SLR simultaneously at observation level  Inter technique calibration  Stochastic parameter evolution between days (arcs)  Utilization of parameter statistics  Accelerometry: GOCE POSITIONING DATA – FOR SOCIETY’S BENEFIT

4. KARTDATA TIL NYTTE FOR SAMFUNNET DETERMINATION OF LOCAL GRAVITY (NORWAY)  Norwegian Mapping Authority (NMA):  Contribute to the determination of climate parameters  Determine the cm geoid  Transfer of GEOSAT competence from NDRE to NMA  Why local analysis?  ESA -> SH expansion: truncation issues (40,000 parameters)  May still be information left in accelerometer signal  Norway gravitationally “rough” POSITIONING DATA – FOR SOCIETY’S BENEFIT

5. KARTDATA TIL NYTTE FOR SAMFUNNET STRATEGY POSITIONING DATA – FOR SOCIETY’S BENEFIT

6. KARTDATA TIL NYTTE FOR SAMFUNNET SINGLE ACCELEROMETER OBSERVATIONS  Benefits:  Less susceptible to accelerometer failure  Algorithms applicable to other missions like GRACE  Disadvantage:  Non-gravitational force has to be modeled as part of gravity field determination POSITIONING DATA – FOR SOCIETY’S BENEFIT

7. KARTDATA TIL NYTTE FOR SAMFUNNET ACCELEROMETER OBSERVATION EQUATION POSITIONING DATA – FOR SOCIETY’S BENEFIT Output of accelerometer j: True acceleration:

8. KARTDATA TIL NYTTE FOR SAMFUNNET ATTITUDE CORRECTIONS POSITIONING DATA – FOR SOCIETY’S BENEFIT GRF 2 CRF rotation matrix: Indirect effect on true acceleration: :

9. KARTDATA TIL NYTTE FOR SAMFUNNET DYNAMIC ORBIT DETERMINATION/CALIBRATION POSITIONING DATA – FOR SOCIETY’S BENEFIT Computation of orbit: Expression for non-gravitational force D dependent instrument imperfections? Accelerometer orbit-GPS orbit=instrument imperfections

10. KARTDATA TIL NYTTE FOR SAMFUNNET Estimate of D for Dynamic Orbit Determination LSQ applied to accelerometer observations with D as only unknown: POSITIONING DATA – FOR SOCIETY’S BENEFIT

11. KARTDATA TIL NYTTE FOR SAMFUNNET CALIBRATION BY DOD  Issue: Along-track scale factor not well determined from DOD alone due to along-track DFC (Visser, 2009) POSITIONING DATA – FOR SOCIETY’S BENEFIT  Solution?: Simultaneous determination of orbit and local gravity field

12. KARTDATA TIL NYTTE FOR SAMFUNNET PARALLELL AND FUTURE  Altimetry: Sea level & ocean currents (NMA) POSITIONING DATA – FOR SOCIETY’S BENEFIT  GRACE  WEAKNESSES OF GRAVNOR???