Investigation of the Observability of a Satellite Cluster in a Near Circular Orbit.

摘要

The relative position determination of a cluster of satellites in a nearly circular orbit was previously investigated with the use of dynamics based on the Clohessy-Wiltshire equations and an on-board estimator based on the U-D covariance factorization version of the Kalman filter. The initial performance results proved favorable, with the filter meeting the required 25 meter accuracy in all test cases. The purpose of this thesis is to validate the test results achieved by Captain Ward and to investigate the ability of the filter to determine the relative position of the satellites to a higher degree when the filter in use is not resident on that satellite. This investigation included the use of additional measurement data from other satellites in the cluster to the Kalman filter for processing in the update cycle. WHen it was determined that the measurements were not allowing satellite 1 to update, the observability of the components of the state vector were computed and the results discussed. Theses. (JHD)