High Precision GPS IIR Orbit Prediction using Analytical Non-conservative Force Models

摘要

The geodesy research group at University College London has developed a suite of generalised nonconservative force modelling tools. These tools model the response of a satellite to: solar radiation pressure, anisotropic thermal re-radiation, forces due to radiation both reflected and emitted by the Earth (termed albedo/long wave infrared effects), and the force effects due to the transmission of the microwave navigation signals. In addition, the variation in the incident radiation flux as the satellites pass through the penumbra is modelled. The modelling techniques are designed to deal with realistic, complex satellite structures without any geometrical simplification required in the model computation process. The tools can be applied to any satellite. rnThe solar radiation pressure and thermal re-radiation modelling tools have been described in earlier papers. This paper gives a detailed description of the albedo/IR techniques and the signal transmission force effects. The complete suite of tools has been applied to the GPS Block IIR satellite. All these forces are shown to have a significant effect on the satellite trajectory and can be modelled successfully a priori. rnTo assess the force model accuracy the orbits of GPS Block IIR satellites are predicted and then compared to the post-processed precise orbits, which are used as a truth model.