X-ray Pulsar-Based Autonomous Navigation And Its Application To High Earth Orbits Satellites

X-ray pulsar-based navigation is a navigation method using celestial X-ray source observations for spacecraft attitude, position, velocity and time determinations. Normally, it is called XNAV. It is one of the hotspots in current satellite autonomous navigation involving astronomy, geosciences, spatial science .etc. This dissertation focus on the X-ray pulsars based navigation method and its application on the high earth orbits satellites autonomous navigation, which mainly consists of these following parts.The theoretical basis of the XNAV is analyzed firstly. The time transfer equation is given which shows the relationship between the TOA in the satellite and the SSB. Photon TOA transformation equations are developed . Pulse standard profile and pulse timing models are analyzed. The unique pulsar mechanism and properties are the physical premise for navigation, while the transformation equation and the pulse timing modes are the tow basic mathematical foundation.The principles and algorithm of the satellite orbit determining in Earth Centered Inertial coordinate system is presented. The geometrical orbit determination theory using the pulse TOA information is given, and the measuring equations using the pulse phase information are established. The Extend Kalman Filter (EKF) is used to blend the X-ray pulsars measurements and the orbit dynamics information. The orbit predict values are used in the quick ambiguity resolution and computing the relativistic corrections approximation in the TOA transformation equation. The simulation results demonstrate the suggested algorithms are achievable.For reducing the complexity of system and the test cost, a scheme that only using single X-ray pulsar detector in spacecraft and the integration of single X-ray pulsar and UV sensors are proposed. Piece-wise constant system is used to value observability of the single X-ray pulsar system. The simulation results in several test cases confirm the theoretical analysis. In order to improve the observability, the integration of XNAV and UV sensors are promoted. The simulation results show the integration system has a better navigation performance.In order to improve the reliability and precision of navigation system, the integration of XNAV and GNSS system are developed. Use multiple GNSS to solve the poor visibility problem when using single GNSS. An EKF based Multi-GNSS satellite navigation algorithm is designed. A federated filtering is utilized in the XNAV/GNSS integration navigation system. The integration system has multiple combination patterns in practice. Better navigation performance is obtained by integration. Moreover, the XNAV and GNSS are backup system reciprocally, which provide increased vehicle reliability.Finally, in order to test the methods and algorithms presented above for orbit determination of high attitude orbit satellite, a simulation platform has been developed to verify the proposed scheme and algorithms. This platform is composed of the professional satellite simulation software STK and MATLAB. The results of these test cases are presented. The satellite navigation system has been simulated on the platform and gained good effects. It laid a solid foundation for the practical application of algorithms.The research work in this dissertation is useful for the further developing of the high attitude orbit satellite autonomous navigation, which is valuable in theory and engineering.