Autonomous Navigation Based on Pulsar in Libration Point Orbit of Sun-Earth System

The application of X-ray pulsar navigation in libration point orbit was discussed.The principle of X-ray pulsar autonomous navigation was analyzed.Difference between the real time and the estimated time of pulse arrival was regarded as the basal measurement.The system model was the full ephemeris dynamic model of Halo orbit around L_1 point of the Sun-Earth system.The Unscented Kalman Filter(UKF) based on UD factorization was applied to estimate the state of the system.Perturbation factors were discussed to analyze their influence on navigation precision.The simulation results demonstrate that this algorithm is feasible for the autonomous libration point orbit determination in the Sun-Earth system.The method that applies full ephemeris dynamic model and X-ray pulsar-based navigation principle can accomplish the autonomous navigation mission in the libration orbits.Besides,the navigation results are able to converge and the accuracy is enough to meet the navigation demand.