A Calibration Method for Star Sensors Based on the Zernike Wavefront Aberration Model

Star sensor calibration is essential for obtaining accurate intrinsic parameter values and reconstructing star vectors, thereby ensuring high-precision attitude determination. Traditional calibration methods employ different mathematical models to correct intrinsic parameter errors. However, these methods rely on fitting the observations and are constrained by ambiguous physical interpretations, failing to satisfy the requirements of high-precision applications. To address this problem, a novel star sensor calibration method is proposed in this paper. Based on the wavefront properties, a new physical model is developed to characterize the imaging coordinates of star spots as affected by intrinsic parameters. Subsequently, a corresponding parameter model is derived using Zernike polynomials to relate wavefront aberrations to intrinsic parameter errors, providing a clear physical interpretation for their sources. In addition, a multi-order sequential optimization strategy is designed for parameter calibration to obtain better calibration results. Experimental results confirmed the effectiveness and adaptability of the proposed method for different star sensors. Compared with traditional calibration methods, the proposed method achieves better calibration accuracy with fewer parameters and lower parameter orders.