Abstract: A method of estimating the relative position and rate between a passive spacecraft and a target spacecraft during the home phase of a typical rendezvous and docking mission using a parallel extended Kalman filter (EKF) is proposed. The paper discusses the formulation of EKF for the problem. The proposed parallel square-root algorithm is designed based on the updated singular value decomposition and the Faddeev algorithm. A new systolic array acrchitecture is developed for its implementation. This architecture is more numerically stable than other square-root algorithms, and has higher efficiency and uses fewer time steps for a complete iteration.

Key words: rendezvous-docking, Kalman filters, systolic array