为提高微型星敏感器的质心定位精度, 提出了一种利用外差式激光干涉装置标定图像传感器像素位置偏差的方法, 并就像素位置偏差对星点像质心定位精度的影响进行了仿真研究。在噪声忽略不计的情况下, 当像素位置偏差服从(-0.02, 0.02)上的均匀分布时, 补偿系统误差能够使星点定位精度从0.008 pixel提高到0.002 pixel。而如果加入服从N(0, 5.52)的高斯白噪声, 当像素位置偏差服从(-0.02, 0.02)上的均匀分布时, 补偿像素位置偏差能使定位精度从0.020 pixel提高到0.018 pixel; 当像素位置偏差服从(-0.04, 0.04)上的均匀分布时, 补偿像素位置偏差能使定位精度从0.026 pixel提高到0.018 pixel, 提高了31%。这说明标定像素位置偏差对提升质心定位精度有显著作用, 为发展高精度微型星敏感器提供了一种新的技术手段。

In order to improve the accuracy of centroiding for high precision miniature star tracker, a method to calibrate the imaging sensor pixel displacement using heterodyne laser interferometry was proposed. And the star position error due to imaging sensor pixel displacement was studied by simulation. The simulation results show that the accuracy of star position can be enhanced from 0.008 pixel to 0.002 pixel by compensating pixel displacement when pixel displacement obeys uniformly distributed over the interval (-0.02, 0.02) pixel. When the additive Gaussian noise in the star image has a normal distribution with mean 0 and standard deviation 5.5, if pixel displacement obeys uniformly distributed over the interval (-0.02, 0.02) pixel, the accuracy of star position can be enhanced from 0.020 pixel to 0.018 pixel after compensation; if pixel displacement obeys uniformly distributed over the interval(-0.04, 0.04) pixel, the accuracy of star position can be enhanced from 0.026 pixel to 0.018 pixel after compensation, which are 31% better than the accuracy without compensation. Simulation results show that calibrating pixel displacement which can significantly improves the star position accuracy can be used as a new method to develop high precision miniature star tracker.