New method for attitude determination of spin satellite based on continuous star map observation

Traditional methods for spin satellite attitude determination usually utilize earth sensor and sun sensor as the measurement instruments. The generated system errors and installation error and so on will lead to large spin attitude errors. Considering this problem, a new method using continuous star map acquired by a star sensor to estimate the spin attitude parameters of the satellite was proposed. In this method, the spin axis and the angular velocity of the satellite were used as state variables, and the pixel coordinates of stars obtained through star map matching between adjacent time were used as measurements. The spin attitude parameters of the satellite were estimated by unscented Kalman filter. Simulation results show that with the star sensor accuracy of 3″, the estimation accuracy of the spin axis is less than 0.3448″ and the estimation accuracy of spin angular velocity is of 10^-4(°)/s magnitude.