An analysis of orbital propagators for low earth orbit rendezvous

Abstract

This thesis examines the performance of three different orbital propagators to determine which provide the best performance for use in Low Earth Orbit Rendezvous. The performance evaluation is based upon the propagator's accuracy and the amount oftime required to produce a solution. A Cowell high-fidelity propagator is used as a base line for comparison with an Encke and Clohessy-Wiltshire propagator. To further enhance the examination a Jacchia-70 atmospheric model and a GEM-9 Geopotential model are used to provide perturbing acceleration inputs to the propagators. All comparisons are performed in a Local Vertical, Local Horizontal Reference Frame with the target spacecraft at the coordinate center. Tainting of the input data set by a prior processor make the findings suspect. Findings support the prediction that while the Cowell propagator is the most accurate it also takes the most time to achieve results. Also, the Clohessy-Wiltshire, while taking the least time is the most inaccurate. The Encke propagator deliveries the most balanced result.