Application of multi-rate sensor data fusion in the X-ray pulsar navigation

Pulsars autonomous navigation is characterized by its credible performance and high navigation accuracy, which will have broad prospects for use in deep-space autonomous navigation. In our study, we find the observation time required for different pulsars to obtain the same time of arrival (TOA) accuracy is different, which means the rates of different sensors are different. However, the previous studies assume the pulsars used for navigation have the same observation time. And it will greatly influence navigational accuracy. Therefore, a new multi-rate observation model is presented and multi sensor data fusion is applied to the X-ray pulsar navigation. Combined with unscented Kalman filter (UKF) through simulation, this multi-rate observation model can improve the filtering accuracy effectively.