93-113

Gravity Recovery Analysis Using GPS For Step And A Low-Low Satellite Mission

Ronald J. Muellerschoen*, Willy I. Bertiger** and Sien C. Wu**

Abstract

Global Positioning System (GPS) receivers on low Earth orbiting satellites can provide three-dimensional global tracking with sub-decimeter orbit accuracy. The precise GPS data can additionally be used to refine the Earth's gravity field. STEP is a proposed European Space Agency mission which will carry a flight GPS receiver. Using a realistic scenario for processing 5 days or GPS data, a covariance analysis is performed to obtain the expected improvement in the gravity field. Additionally, a simular analysis is then repeated for two low Earth orbiting satellites, each equipped with GPS receivers and with percise ranging measurements between them.
*Member of the Technical Staff, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109.

**Technical Group Leader, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109.