Multirate Observation-Based X-Ray Pulsar Navigation Technique

X-ray pulsar navigation techniques can provide the information of position and velocity for spacecraft and have proven to be an extremely promising autonomous navigation solution. Currently, one of the main problems of pulsar navigation is that the update rate of the measurement data is low. In this paper, a multirate observation pulsar navigation model is proposed to improve the update rate of measurement data. To solve the uncertainty of the measured angles in the multirate observation model of pulsar navigation, a robust extended Kalman filter (REKF) is also proposed. In order to verify the effectiveness of the model and filtering algorithm, the root-mean square (RMS) errors of the REKF for multirate observation model is compared with the extended Kalman filter (EKF) for a multirate observation model and REKF for a synchronous observation model. The simulations results show that the proposed multirate observation model and REKF are valid to improve navigation accuracy.