Filter performance in target tracking using space-based observers

摘要

The objective of this research was to evaluate the performance of an extended Kalman filter (EKF) and an adaptive EKF in tracking a target vehicle using various measurement types from space-based observers. The adaptive EKF incorporates ridge-type estimation methods to improve the accuracy obtained by the standard EKF. The dynamical model developed for the target vehicle includes the effects of the spherical and non-spherical earth, launch vehicle thrust, and atmospheric drag. Possible observation types considered are azimuth and elevation angles, range, and range-rate data from up to three space-based observers. Comparative studies were made to evaluate the estimation accuracy as a function of observation type, number of observers, and observation rate for an observation time of up to 2 min after target vehicle burnout. In addition, comparisons were made with and without the use of initial orbit determination techniques. Results show that the performance of the adaptive EKF exceeds that of the EKF in a number of scenarios studied.