Observability analysis of satellite constellations autonomous navigation based on X-ray pulsar measurements

A novel autonomous navigation approach based on X-ray pulsar is proposed in this paper. First, the principles of the pulsar-based measurement model and the inter-satellite range model in the autonomous navigation of satellite constellations are presented. Second, the models of constellations system observability and observable degree are built. Finally, the feasibility of the proposed measurement scheme compared with an inter-satellite range scheme is illustrated by using numerical simulations. The results show that the proposed approach is observable to non-coplanar satellite constellation system, and can effectively estimate the right ascension of ascending node of the satellite orbit, which cannot be observed by the inter-satellite range measurement.