Abstract:

Observability of the single pulsar-based satellite autonomous navigation system is studied. The state equation and measurement equation of the system are presented. According to the characteristics of linearization of the extended Kalman filter, the observability analysis of piece-wise constant system (PWCS) is carried out to study the system observability. In the theoretical analysis, the observable matrix of this system is nearly singular, and the system is completely unobservable. It is demonstrated by simulation that, with measurements from only one pulsar, the estimated position and velocity propagated by satellite dynamics can be improved.Errors in position and velocity can be kept within certain limits in short time; but the satellite orbit cannot be estimated accurately over long time.

Key words: X-ray pulsar, satellite, autonomous navigation, observability analysis