Design and predicted performance of the GPS demonstration receiver for the NASA TOPEX satellite

NASA´s ocean topography experiment (TOPEX) satellite will perform topographic ocean mapping. TOPEX will carry an experimental tracking system based on the use of GPS (global positioning system). An onboard GPS demonstration receiver (GPSDR) will be used with a network of up to ten receivers at precisely known ground sites. Following a brief overview of the TOPEX mission and its derived accuracy requirements, the authors describe the design of the GPSDR. The major hardware and software components are reviewed and discussed. Projected receiver tracking and navigation performance measures are presented and discussed