Instantaneous attitude solving algorithm based on reversible linear transformation in star sensor*

Aimed at decreasing the time cost of instantaneous attitude solving in star sensors and enhancing the data updating rate of autonomous attitude determination in aero crafts which utilize star sensor, an algorithm based on reversible linear transformation is proposed. The proposed algorithm transforms the nonlinear equation group which takes the attitude quaternion as unknown values into standard quadratic form according to the characteristics of attitude quaternion, which results in the number of assignment calculation decreasing in the course of solving the equation group of attitude quaternion. The simulation result indicates that the solving time cost of instantaneous attitude is decreased obviously through this algorithm.