Simultaneous Orbit and Network Adjustment in Tennessee

Abstract

An application of single‐session simultaneous orbit and network adjustment of GPS carrier beat phase data is described. In a simultaneous adjustment, both station positions and satellite orbit parameters are estimated from several hours of observations. By reducing the errors in the satellite orbits, the accuracy of surveying with GPS is increased. In October 1987, the Tennessee Department of Transportation established a statewide GPS control network in conjunction with observations from a continental‐scale orbit tracking network in the U.S. and Canada. A subset of these data was reduced in the simultaneous orbit and network adjustment mode resulting in improved orbits, compared to currently available satellite ephemerides, and more precise relative station positions. The analysis was performed on a personal computer making this technique practical for engineering and surveying applications.