Abstract:  X -ray pulsars navigation uses the time of arrival (TOA) of the X-ray pulse radiation to resolve the position. Star sensor based navigation uses the angle between line of sight to the star and the center of earth to resolve the position. The mechanisms of the two navigation systems are different from each other. An information fusion celestial utonomous navigation method was proposed by hybriding the pulsars TOA and elevation angle of star sensor measurement. And the simulation experiments based on unscented Kalman filter (UKF) using real orbit parameters were carried out. A hard-in-loop simulation system which uses the laser quantum to emulate the X-ray quantum of pulsars was designed to test the method. The results show that, comparing to the methods based on pulsars or star sensor only, the estimation accuracy of position and velocity of the proposed method can increase 52.7%, 43.6%, 82.2% and 70.5% respectively, and its performance is better than extended Kalman filter (EKF) information fusion method.

Key words: Celestial autonomous navigation, X-ray pulsars, Star sensors, Unscented Kalman filter, Information fusion, Spacecraft