CoAuthors

Eva Jalabert (CNES, France); Alexandre Couhert (CNES, France); Hanane Ait Lakbir (CS-SI, France); Flavien Mercier (CNES, France); Sabine Houry (CNES, France)

Following an extended safe hold mode encountered since May 2017, the NASA/CNES Jason-2 spacecraft (approaching its first decade of duty) was placed into a long-repeat orbit (LRO) beginning of July 2017. In October 2016, Jason-3 had already taken over from its predecessor, as the altimeter reference mission, and is now completing its second year in orbit. Along with Jason-3, the EU Copernicus Sentinel-3A satellite complements the sea level data legacy for more than a year. With the benefit of hindsight, it is now time to consider reprocessing these three missions (Jason2, Jason3, Sentinel-3A), especially as many things (dynamic and measurement models) have improved since the last GDR-E orbit standards (2014).
Preliminary GDR-F precise orbits for Jason-2, Jason-3 and Sentinel-3A will thus be presented in this paper. The main evolutions concern the use of station coordinates from ITRF/DPOD/SLRF2014, the modeling of the non-tidal geocenter variations (DORIS-only estimation based on Jason-2) , an update to the conventional model for rotational deformation as well as time-variable gravity modelling, the improvement of instrument phase center locations, the fixing of ambiguities for the Jason-3 GPS receiver. Comparisons to the current GDR-E and available external solutions will be shown, as a complement to independent SLR validations.