Deployment of the NAVSTAR Global Positioning System will result in a source of precise navigation data for a variety of users. Although the majority of the users will operate in the near-earth environment (e. g. , manpacks, aircraft, and ships), certain satellite configurations may also take advantage of the GPS measurements. Projected tracking performance for a class of user satellites, using GPS measurements, is presented in this paper. User satellite tracking filters, with dimensions ranging from 8 to 12, were formulated and evaluated against a truth model containing 277 sources of error. Optimal smoothing using the GPS measurements was also considered. The detailed results of the proposed satellite-to-satellite tracking concept are summarized, compared, and interpreted herein.
