Spacecraft Celestial Navigation Method Based on Laser Ranging Auxiliary

The method of pure angle observation has serious nonlinearity in celestial navigation system, the angle measurement error is converted to a large distance error, which caused navigation accuracy degradation. Aiming at the problem of celestial navigation accuracy, this paper proposes a celestial navigation method based on laser ranging auxiliary. High-precision distance measurement from satellite to ground reference beacon can be directly obtained by means of laser ranging. In the celestial navigation system which takes the starlight angular distance as the observation measurement, the introduction of laser ranging auxiliary data can not only expand the filter observation dimension, but also improve the filtering effect obviously. Meanwhile, in order to reduce the second-order truncation error due to the linearization of Taylor expansion, it is necessary to use the unscented Kalman filter (UKF) method for the data fusion of integrated navigation system. Research results show that integrated navigation system of celestial navigation and laser ranging can significantly reduce estimation error and improve the navigation accuracy.