A Modified SDREF for Autonomous Navigation of Distributed Satellite Systems

Abstract

The autonomous navigation problem of distributed satellite system is studied in this paper. State-dependent Riccati equation filter (SDREF) is introduced to the autonomous system which consists of two satellites and use relative position measurements. The difference between SDREF and extended Kalman filter (EKF) is compared in computation and filtering step. It is proved that when the SDREF satisfies certain conditions, it can drastically reduce the amount of computation compared to EKF. This paper also propose a modified state-dependent Riccati filter (MSDREF) based on system observable degree by adjusting the error covariance matrix in standard SDREF on line. Numerical simulation results illustrate that the MSDREF can significantly restrains the error augmentation phenomenon in standard SDREF when the system observability is weak.