A Covariance Study for Orbit Accuracy Improvement of the GPS Satellites Using Fiber Optics Tracking

William S. Schreiner

Abstract:	With the use of the NAVSTAR Global Positioning System (GPS) constellation, it is possible for military and civilian users operating GPS receivers to compute accurate receiver positions in both low Earth orbit and on the surface of the Earth. This positioning accuracy is greatly dependent on the accuracy of the GPS orbits that are used in the estimation process. Unfortunately, current GPS orbit accuracy limits the amount of scientific information that can be retrieved from many geodetic applications such as oceanography and crustal dynamics where precise positioning is required. For example, the altimetric satellite TOPEX which carries a GPS receiver will need 50 to 100 centimeter accurate GPS orbits to answer many climate and global change issues such as mean sea level rise. This limitation of the current GPS orbit accuracy (i.e. 10 to 20 meters rms for USAF broadcast orbits) motivated the preliminary development of a new orbit determination system that could provide sufficient GPS orbit accuracy for the scientific community. This paper presents an alternative GPS orbit determination system that consists of a relatively closely spaced fiducial tracking network that is time and frequency synchronized by a fiber optic link. The paper describes the proposed fiber optics tracking system and presents preliminary results of a covariance study that indicate the possibility of achieving sub-meter on-orbit accuracy. The covariance analysis was completed with the Orbit Analysis Simulation Software (OASIS) which was developed at the Jet Propulsion Laboratory (JPL).
Published in:	Proceedings of the 3rd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1990) September 19 - 21, 1990 The Broadmoor Hotel Colorado Spring, CO
Pages:	563 - 568
Cite this article:	Schreiner, William S., "A Covariance Study for Orbit Accuracy Improvement of the GPS Satellites Using Fiber Optics Tracking," Proceedings of the 3rd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1990), Colorado Spring, CO, September 1990, pp. 563-568.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In