Implementation of a Differential Geometric Filter for Spacecraft Formation Orbit Estimation

摘要

The differential geometric filter is implemented to estimate the absolute andrelative positions of the spacecraft in a formation. The extended Kalman Filter isalso implemented as a benchmark for the differential geometric estimation. Onlyrelative positions between the spacecraft are measured. Relative positions are measuredusing a wireless local positioning system (WLPS) installed in all spacecraft. Two different scenarios are studied: (1) the observations include WLPS measurementsonly and (2) the observations include WLPS measurements in addition tomeasurements for the absolute position of one spacecraft made by a radar thattakes measurements from the earth’s surface. Results show that the differentialgeometric estimation has better stability performance and a faster convergencerate compared to the extended Kalman filter.