Star sensor calibration with separation of intrinsic and extrinsic parameters

The calibration method based on integrated modeling with intrinsic and extrinsic parameters is widely used for star sensors. However, the unified optimization of parameters results in the coupling between intrinsic and extrinsic parameters in this method, further influencing the calibration accuracy of the intrinsic parameters and causing certain limitations for the practical applications involving precise extrinsic parameters. A novel calibration method for star sensors with separation of intrinsic and extrinsic parameters is proposed in this paper to solve the issue. Firstly, the coupling form of intrinsic and extrinsic parameters in the integrated calibration model is analyzed, and the coupling degree is analyzed through the partial correlation coefficient (PCC). Then, on the basis of the analysis results, combined with the applications of star sensors in satellites and missiles, the extrinsic parameters coupled with the intrinsic parameters are separated individually, and the intrinsic and extrinsic parameters without coupling are optimized nonlinearly as a whole. The experimental results verify the validity of the proposed method.