Improving the estimation of the geocenter for orbit solutions: Impact on Sea Surface Heigh estimation

Annabelle Ollivier (CLS, France)

CoAuthors

Marine Lievin (CLS, france); Alexandre Couhert (CNES, France); Flavien Mercier (CNES, France); Alejandro Blasquez (CNES, France); Nicolas Picot (CNES, France)

Event: 2016 Ocean Surface Topography Science Team Meeting

Session: Precision Orbit Determination

Presentation type: Type Oral

The comparison of orbits solutions using different geocenter positions (Pure GPS, Pure DORIS…) highlight large scale geographical patterns with a slight signature at the yearly period (North South oscillation of up to 5mm) (Cerri et al. 2013).
POD teams believe that these observations could be the signature a potential error remaining in the estimation of the geocenter position in the POD models. Indeed, recent theoretical studies showed that this error could be understood and solved (Mercier and Couhert et al. 2015).
But for these referencing problems, it is hard to determine if a solution is better or worse than another one. To answer this question, we propose in this study to check the impact of such changes on the Sea Surface Height (SSH) computed with altimetry.

Using Jason-2 CNES POD test solutions with different geocenter positioning, we show how the geographical and temporal signatures are reduced or increased. Comparisons to in situ ARGO profiles also give information about the relevance of each reference position. These studies could enable to identify the best solution and further, to better classify the terms of large scale variability for Climatic closure budget purposes (see abstract Blasquez, Meyssignac et al.).
 

Oral presentation show times:

RoomStart DateEnd Date
Auditorium Wed, Nov 02 2016,12:05 Wed, Nov 02 2016,12:20
Annabelle Ollivier
CLS
France
aollivier@cls.fr