星敏感器标定是基于更高精度的测量基准对光学系统内方位元素进行建模与最优化解算的过程。针对大视场星敏感器光学系统误差分布非理想轴对称的实际情况, 提出了一种采用视场网状分区域建模的内方位元素最优化解算方法。首先, 在补偿了星敏感器与标定系统初始对准误差后, 基于针孔模型计算主点和焦距; 然后, 在视场分区域建模思想的指导下, 采用多项式拟合结合双线性插值的方法修正畸变; 最后, 提出了基于测角误差的标定精度评价准则。经实验室标定与外场观星验证, x轴与y轴标定残差较全局建模法分别降低了35%和20%, 证明了该方法的有效性。

Based on the measuring benchmark of higher precision, the inner orientation elements of star tracker were modeled and optimized. Because of the fact that the error of the optical system with large FOV is not ideally axial symmetry, a calibration model based on net zone-division field of view and the corresponding optimization method was proposed to calculate inner orientation elements of star tracker. Firstly, the principle point and focal length were resolved based on pinhole model after the compensation of initial alignment error. Then, the polynomial combined with bilinear interpolation was used to correct the optical distortion under the guidance of zone-division modeling theory. Finally, measurement angle error was applied to the accuracy evaluation of calibration. A calibration experiment in lab and a real sky test validated the proposed method with the residual error of x axis decreased by 35% and y axis decreased by 20%.