<h2>AAS 99-201</h2>
<h2>Reducing Selective Availability Effects on Post-Processed Orbits for Satellites with Limited GPS Telemetry                                       </h2>
<h4>D. Mickler, P. Axelra, G. Born                                                                                                                                                      </h4>
University of Colorado, Boulder                                                                                                                                           
<h2> Abstract </h2>
Many current satellite mission are using GPS for navigation solutions. The accuracy from on-board standalone GPS (about 100m RMS) is adequate for many real-time needs. In an effort to reduce the complexity of the receiver to spacecraft interface, some missions are providing only GPS receiver position and velocity solutions (and basic status information) in the telemetry stream. Lack of raw GPS code and phase observations preclude high precision post-mission orbit estimation.