APPLICATIONS OF GPS TO SPACE-VEHICLES - ANALYSIS OF SPACE ENVIRONMENTAND ERRORS

GPSbased systems become extremely competitive for space applications b ecause of their all-weather capabilities and continual information on position, velocity, precise time and even attitude to increase mission effectiveness, reduce mission cost, minimize requirements of on-board devices. In this paper, space application environment and error sourc es have been systematically analyzed, including geometric location of user with GPS satellites, dynamic state, physical environment and the effects on positioning accuracy. Several special differential GPS tech nologies to space use are proposed.