Using the Extended CODE Orbit Model

The Extended CODE Orbit Model, an empirical orbit model proposed by Beutler et al. [1994], was used for the first time in the actual parameter estimation procedures (using the Bernese GPS Software), to model the orbits of the GPS satellites at the CODE Analysis Center of the IGS. Apart from six Keplerian elements this orbit model consists of nine instead of the usual two parameters to take into account the deterministic part of the force field acting on the satellites. In this article we focus on the optimum use of this Extended CODE Orbit Model for the CODE IGS activities. Of particular interest are the generation of rapid orbits, with only 12 hour delay after the last observation, and (IGS) orbit prediction.