New Techniques for Orbit Determination of Geosynchronous, Geosynchronous-Transfer, and Other High-Altitude Earth Orbiters

This paper explores two innovative approaches to high-altitude orbit determination. GPS-enhanced tracking (GET), which has been field-tested by JPL with two geosynchronous satellites, utilizes inexpensive ground terminals developed from commercial GPS receivers. The second approach involves tracking GPS directly onboard, soon to be tested by JPL with a new microGPS receiver, also known as the Bit Grabber GPS Space Receiver (BGGSR), requiring <0.1 watt power on average. First BGGSR launch is anticipated late summer 1997. A 1998 launch is planned for STRV1 C in geosynchronous-transfer orbit to track GPS over a wide a]titude range. The paper discusses experimental setup and positioning results from ground and space data analysis for these new techniques.