Static positioning with the global positioning system (GPS): State of the art

We are now looking back at five years of practical experience with the test configuration of the GPS. This time span allowed to gain good insight into the capabilities and the problem areas of this system. Processing techniques evolved from pure baseline, session, and L1 carrier oriented to network, project, and dual frequency oriented modes. Several institutions developed software capable of orbit improvement and demonstrated that the ultimate accuracy to be obtained by GPS is close to that of VLBI for regional surveys, and, close to that of the most advanced terrestrial techniques in small size networks.