Shailen Desai (JPL, country); Angie Dorsey (JPL, country); Bruce Haines (JPL, country); Felix Landerer (JPL, country); Aurore Sibois (JPL, country); Dah-Ning Yuan (JPL, country)

Time-Variable Gravity, Geocenter and Jason-2 Orbit Determination With GPS

Willy Bertiger, Shailen Desai, Angie Dorsey, Bruce Haines, Felix Landerer, Aurore Sibois, and Dah-Ning Yuan

There are several competing models for the both time variable gravity (TVG) and geocenter motion. In the presentation, we will examine TVG models from GeoForschungsZentrum (GFZ), Jet Propulsion Laboratory (JPL), and Goddard Space Flight Center (GSFC) and the effects on the Jason-2 orbit determined with GPS data. Geocenter motion affects both the dynamical model for a low Earth orbiter as well as the apparent coordinate system of the orbit. Since reference frame translations are filtered through the determination of the GPS orbits and the Jason-2 orbit the effect of a change in geocenter on the Jason-2 orbit is complex. We will examine two models of geocenter motion. One derived from Satellite Laser Ranging (SLR) and the other derived from GPS constellation dynamics and their effects on the Jason-2 orbit coordinates.