Abstract: Affected by the space environment, the relative installation errors among optical heads of multi head star sensor vary periodically in orbit, which directly affects the accuracy of fusion. A method is proposed to improve the attitude measurement accuracy of multi FOV star sensors. The star vector error is used as the observation to estimate and compensate the installation matrix error between two optical heads in real time. Based on star vector error characteristics, the installation error estimation parameters are corrected to improve the accuracy of matrix estimation. A multi field star selection strategy is designed and adopted to select high quality stars for fusion attitude calculation.Ground simulation and in orbit application results show that the method can achieve the same accuracy of the three axis attitude. The accuracy is improved by more than 30% compared with the single head.

Key words: star sensor, multi FOV, attitude measurement accuracy, installation error estimation