Research on Calibration System of Star Sensor Thermal Drift Based on Error Decoupling

A star sensor thermal drift calibration system based on error decoupling is proposed. According to the calibration principle and the simulation requirements of the star, a self-collimation optical calibration system and an error decoupling optical path are designed. According to the characteristics of common optical path, the installation deformation error of the star sensor and the coupling error caused by the thermal deformation and the installation deformation are obtained by the autocollimator and the CCD, removing the installation deformation error from the coupling error to obtain accurate star sensor attitude shift quaternion. The simulation results show that the maximum variation errors of the star sensor around the axes are 0.2638, 0.1317, 0.0472(″)/℃ in the environment range of-25～60 ℃, respectively, and the errors are controlled in the range of 0.02(″)/℃ with the ideal result. This provides a new idea and method to reduce the coupling error generated in the calibration of star sensors and improve the accuracy of thermal drift calibration system.

Design the basic common optical path system required for star sensor calibration based on the required field of view and error measurement requirements. Based on the principle of angular distance measurement, establish a calculation model for star sensor angle error. Simulation experiments show that this error model can improve the accuracy of thermal drift calibration and meet the system design requirements. The star sensor thermal drift calibration system studied in this article fully utilizes the optical structural space, simplifies the complexity of the system, reduces costs, and is easy to operate and implement.