COMPARISON OF GPS S/C ORBITS DETERMINED FROM GPS AND SLR TRACKING DATA

The last two Global Positioning System (GPS) spacecraft launched on August 30, 1993 and March 10, 1994 carried identical laser retroreflector arrays that allow laser ranging from ground stations. Tracking of these targets is a low priority for most of the ground stations due to the present mandatory support of missions with no alternative tracking. The available data is sparse and concentrated primarily on the first of the two spacecraft, GPS-35 (PRN 5). Despite this, analysis of this data set indicates that there is great potential for engineering and scientific experiments in a synergistic application of Satellite Laser Ranging (SLR) and radiometric GPS techniques.