Keeping Track of Geostationary Satellites - A novel and less costly approach

摘要

The usual way to establish a satellite's orbit is based on measuring the distances between it and so-called 'ranging antennas' on the Earth at different times. These distances are determined by measuring the time needed for a radio signal to make the round trip between the ranging antenna and the spacecraft. If this distance is measured at several different times, and possibly also using several antennas at different geographical locations on the Earth's surface, the spacecraft's orbit can be uniquely identified. Parameters affecting the spacecraft's motion, such as the solar radiation pressure or imperfectly known equipment parameters like delays in the spacecraft's transponders and/or in the ranging equipment on the ground, can be identified/determined as part of this process. Determining these additional parameters makes the mathematical modelling more precise and therefore also increases the accuracy with which the spacecraft's true orbit can be established.