Journal of Astronautics ›› 2017, Vol. 38 ›› Issue (2): 152-158.doi: 10.3873/j.issn.1000-1328.2017.02.006

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A Method of Autonomous Navigation Using the Magnetometer and Star Sensor

ZHANG Tao ,ZHENG Jian hua,GAO Dong   

  1. 1. National Space Science Centre, Chinese Academy of Sciences, Beijing 100190, China;
    2. Key Laboratory of Electronics and Information Technology for Space Systems, Chinese Academy of Sciences, Beijing 100190, China;
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-08-22 Revised:2016-12-07 Online:2017-02-15 Published:2017-02-25

Abstract:

High precision magnitude information of the geocentric vector can be obtained using a magnetometer, as the gradient of the magnetic field along the altitude direction is large. High accuracy orientation information of the geocentric vector can be obtained using a star sensor. Combining the advantages of the magnetometer and the star sensor, an integrated autonomous navigation method is proposed. To reduce the computation and improve the navigation accuracy and convergence rate, the orbit dynamics equation in the Earth-centered Earth-fixed (ECEF) reference frame is established as the navigation system state equation. The extended Kalman filter (EKF) algorithm is designed for the integrated autonomous navigation system. Numerical simulation is implemented under the real magnetic measurement data of the Alpha satellite of the Swarm constellation. Simulation results show that the proposed method can improve both the convergence rate and the navigation precision, and the position accuracy and speed accuracy are on the order of 0.52km (1σ) and 0.89m/s (1σ) respectively.

Key words: Autonomous navigation, Magnetometer, Star sensor, Swarm satellite constellation, Extended Kalman filter (EKF)

CLC Number: