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PCOP: A System For Long-Term Satellite Ephemeris Predictions

Kenneth E. Williams*

Abstract

This paper discusses a system for predicting orbits for near-earth satellites without drag compensation systems. This system, known as the Personal Computer Orbit Predictor (PCOP), is intended to provide orbital elements suitable for station alerting for periods of up to one year into the future. A functional overview of PCOP is provided. The performance of PCOP is compared with that of typical short-arc orbit propagators, including the Naval Space Surveillance Center's SHOWHOW and the U.S. Space Command's general perturbations model SGP4.

*The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20273-6099.