CoAuthors

Jean-Michel Lemoine (CNES, France)

The satellites Jason-3 and Sentinel-3A were added in the DORIS processing chain of the CNES/CLS Analysis Center. The DORIS Ultra Stable Oscillators for these satellites are sensitive to the South Atlantic Anomaly (SAA) effect at a level which is lower than that of Jason-1, but still 4 to 5 times higher than that of Jason-2. So, for the POD of these 3 satellites (Jason-2&3 and Sentinel-3A), the SAA effect can be neglected but for the station position estimation, it must be taken into account. Indeed, we show here the impact on the station position estimation for some stations in the vicinity of the SAA area by comparison of the single satellite solutions.
Thanks to the extremely precise time-tagging of the T2L2 experiment on-board Jason-2, A. Belli and the GEOAZUR team managed to draw up a model that accurately represents the variations of Jason-2 USO’s frequency. This model will be evaluated by analyzing its impact on the position estimation of the SAA stations. While awaiting a DORIS data corrective model for the others satellites Jason-3 and Sentinel-3A, a solution will be proposed to minimize the SAA effect on the orbit and also and in particular on the station position estimation.