Satellite Orbit Determination Using a Single-Channel Global Positioning System Receiver

A proposed satellite orbit determination system has been analyzed, one that uses measurements from a single-channel Global Positioning System (GPS) receiver. The purpose of this study is to predict the likely efficacy of a low-power autonomous orbit determination system. The system processes the pseudo range outputs of the receiver using an extended Kalman filter. The receiver cycles through different GPS satellites, tracking a new one every 75 seconds, in order to achieve observability and reasonable accuracy. The Kalman filter uses a dynamic model of the spacecraft orbit and of the receiver clock's drift. Simulation results predict that the system can achieve peak per-axis position errors that range from 78 m to 144 m when in low Earth orbit. The accuracy depends on the level of uncertainty in the orbital dynamics model. The system can also operate in a geosynchronous orbit, but its peak per-axis error degrades to 7 km if the filter neglects Solar and Lunar gravity terms, and the geosynchronous receiver must use an ovenized crystal oscillator as its clock.