Method research of multiple star sensors ground thermal drift calibration position error detection

In order to reduce the affect of the deformation offset of different installation platforms on the ground thermal drift calibration of multiple star sensors, a multiple star sensor ground thermal drift calibration position error detection method was proposed. Theoretical analysis and experimental verification were carried out. The position deviation data of the reference square prism deformation in the system under the vacuum of-25℃～60℃ was obtained. And the accuracy analysis of calibration position error was carried out.The results show that, the maximum offsets of the multi-star sensor positions around each axis are-39.341″/℃,-0.060″/℃, and-24.137″/℃, repectively. By establishing the error detection model which was established according to the method of measuring position error, the position error was removed from the offset of the attitude measurement result to obtain a more accurate star sensor attitude measurement quaternion. And the system accuracy after removing the position error was improved by at least 11%, which means it has a good application prospect in improving the accuracy of star sensor thermal drift calibration.

A study was conducted on the detection method of thermal drift calibration position error for multi star sensors. According to the working principle of the multi star sensor calibration system, a position error detection model for the multi star sensor was designed. Based on this model, the attitude offsets caused by the position error were calculated to be -24.660 ″/℃, 0.015 ″/℃, 0.159 ″/℃, and the maximum changes were -39.341 ″/℃, -0.060 ″/℃, and -24.137 ″/℃, respectively. Finally, simulation experiments and calculation results confirm that the position error detection model can effectively improve the accuracy of system thermal drift calibration and simplify the complexity of the calibration system.