Integrated XNAV/Inter-Satellite Measurement Navigation Algorithm for Spacecraft Formation

Due to the increasing requirement of autonomous navigation for spacecraft formation, an integrated navigation algorithm based on XNAV and inter-satellite measurement is suggested. First, the navigation system architecture is established according to the formation flying dynamics and observed principle. Then, the navigation filter is presented. The filter has a multi-estimated architecture by virtue of the non-correlation of formation state, which can improve the navigation observability and computed efficiency. Meanwhile, a novel cubature Kalman filter is suggested which is more stable and suitable for high dimensional system. Furthermore, a covariance adaptive strategy based on recursive random weighting is developed for the deficiency of low sample rate in XNAV. Finally, simulation results validated the efficiency and effectiveness of the integrated navigation architecture and algorithm. The algorithm here is universal and can benefit researches on the autonomous navigation for spacecraft formation, especially for the vehicles flying in high earth orbit or interplanetary.