AAS 95-443

Tracking and Data Relay Satellite System (TDRSS) Support of User Spacecraft Without TDRSS Transponders

J. Jackson and G. C. Marr, NASA Goddard Space Flight Center,Greenbelt, MD, M. Maher, Allied Signal Technical Services Corp.

Abstract

NASA GSFC VNS TSG personnel have proposed the use of TDRSS to obtain telemetry and/or S-band one-way return Doppler tracking data for spacecraft which do not have TDRSS-compatible transponders and therefore were never considered candidates for TDRSS support. For spacecraft with less stable local oscillators (LOs), one-way return Doppler tracking data is typically of poor quality. It has been demonstrated using UARS, WIND, and NOAA-J tracking data that the simultaneous use of two TDRSS spacecraft can yield differenced one-way return Doppler data of high quality which is usable for orbit determination by differencing away the effects of oscillator instability.