The research on X-ray pulsars/COMPASS integrated navigation for spacecraft

X-ray pulsars navigation is a newly developed celestial navigation method, but the filter cycle time is long, and it cannot provide continuous navigation information. COMPASS can provide all-weather and continuous navigation information, but it has poor dynamic performance, and is susceptible to electromagnetic interference and the satellite signal is easy to be blocked. A X-ray pulsars/COMPASS integrated navigation method was proposed in order to improve the autonomous navigation capability of spacecraft. In this case, an autonomous orbit determination method of spacecraft is proposed through federal filtering that combines COMPASS navigation with X-ray pulsar navigation system. The extended Kalman filter (EKF), unscented Kalman filter (UKF) and the square root unscented Kalman filter (SR_UKF) algorithm are applied as the sub-filter. Simulation shows that the integration of the two systems can provide a higher accuracy of orbit determination, and SR_UKF performs better than EKF and UKF in filtering precision and stability.