Identification of star sensor low-frequency error parameters

A new method is proposed to identify the parameters of the low-frequency error (LFE) of the star sensor. The LFE is one of the most dominant error sources in the high-precision attitude determination system for the satellite. It is shown that the gyroscope bias estimate, which is obtained by processing the star sensor measurement in the stellar inertial attitude determination Kalman filter, represents the variation in the LFE. As the LFE is a periodic signal, the LFE parameters can be identified from the frequency spectrum of the gyroscope bias estimate. The identified parameters are used for the LFE compensation, such that the effect of the LFE to the attitude estimate is partly eliminated. The efficiency of the proposed method is illustrated through numerical simulations with the use of the real gyroscope data.