A Novel Celestial Aided Time-Differenced Pulsar Navigation Method Against Ephemeris Error of Jupiter for Jupiter Exploration

Subjected to the current observation technology, the planetary ephemerides which are used to predict the positions of planets are not accurately known. For .Jupiter exploration, ephemeris error of Jupiter will greatly degrade the performance of navigation system. To improve the autonomous navigation performance, a novel celestial aided time-differenced pulsar navigation method against ephemeris error is proposed. Time-differenced time-of-arrival (TDTOA) is adopted as measurement to eliminate the system bias caused by the ephemeris error of Jupiter. Because TDTOA cannot work individually, the celestial measurement adopting Jupiter as near celestial body is added to provide the position information of the spacecraft with respect to Jupiter. Unscented kinematic and static filter is used as the navigation filter. Simulations demonstrate that the proposed method can acquire similar accuracy compared with the ideal scenario when there is no ephemeris error of Jupiter, which indicates that the impact of ephemeris error of Jupiter can be eliminated effectively by the proposed method. Moreover, the proposed method can acquire better navigation performance than using celestial measurements or TDTOA measurements individually.