Abstract
The Topex/Poseidon satellite, launched in 1992, is now in its sixth year of operations and third year of extended mission. The last two years have been characterized by minimal resources, two major satellite anomalies, reduction in Satellite Laser Ranging (SLR) tracking data, and some GPS Development Receiver problems. Despite these shortcomings, the Precision orbit determination and Verification Team has improved the processing of its Medium precision Orbit Ephemerides (MOE), now provided to the science community three days after-the-track instead of the four-day baseline without loss of precision. Comparison between the previous four-day processing and the approved three-day delivery is presented, together with a performance summary of the 'quick-look' orbit determination using GPS and SLR tracking data since the beginning of the extended mission. The main feature of this process is that MOE orbits are produced with small radial position error (less than 5 cm rms), on a short prediction schedule (three days). The quick-look orbits are used in support of the Interim Geophysical Data Record production. (Author)