The X-ray pulsar based navigation (XNAV) is a new celestial navigation concept for the spacecraft. The autonomous orbit determination algorithm using pulse phase difference of X-ray pulsars is investigated for navigation satellite. The transmission time of the X-ray pulse from the satellite to the solar system barycenter is analyzed. The measurement equation of the satellite position is described with the pulse phase difference between the satellite and the solar system barycenter. The extended Kalman filter, which incorporates the navigation satellite dynamics and the pulse phase-based measurements, is developed to estimate the satellite orbit. Considering that the satellite position predicted by satellite orbit dynamics is accurate, the predicted satellite position is utilized to determine the cycle ambiguities, and this method is tested feasible. Simulation results demonstrate that this navigation algorithm can provide absolute position of the navigation satellite in the Earth centered inertial frame.
|Number of pages||6|
|Journal||Yuhang Xuebao/Journal of Astronautics|
|Publication status||Published - Jul 2009|
- Autonomous navigation
- Cycle ambiguity
- Phase difference
- X-ray pulsar