Reprocessing TOPEX/Poseidon precise orbits in the GDRE standards

Hanane Aït-Lakbir (CS SI (POD CNES), France)


Alexandre Couhert (CNES, France); Sabine Houry (CNES, France); Eva Jalabert (CNES, France); Flavien Mercier (CNES, France); John Moyard (CNES, France)

Event: 2016 Ocean Surface Topography Science Team Meeting

Session: Precision Orbit Determination

Presentation type: Type Poster

The TOPEX/Poseidon (T/P) mission was launched in 1992 and lasted for 13 years. As a result, a lot of data was collected enabling to monitor the sea level over a long period of time. To this end, its orbits were precisely determined using especially DORIS and SLR measurements. This poster describes the preliminary results of a reprocessing of the T/P orbits in the GDRE standards, currently used by Centre National d’Etudes Spatiales (CNES).
Because SLR data are only used to independently validate the GDRE orbit solutions, DORIS+SLR and DORIS-only orbits were analyzed to gauge the contribution of SLR data in the T/P orbit determination performance. Both dynamic and reduced-dynamic orbits have been considered. The second objective of this study was to cope with a limitation of the gravity field model used in the GDRE standards, for which GRACE time series were not available before 2002 and thus for a long part of the T/P mission. To this purpose, solving for the degree 3 order 1 spherical harmonic terms was tested when computing dynamic orbits. The different orbit solutions were then compared to an external set of orbits, the std1504 orbits from Goddard Space Flight Center (GSFC), through in particular altimeter crossover residuals and geographically correlated orbit differences.

Poster show times:

RoomStart DateEnd Date
Grande Halle Thu, Nov 03 2016,11:00 Thu, Nov 03 2016,18:00
Hanane Aït-Lakbir