图像传感器辐射损伤对光通信系统跟瞄精度的影响分析

The influence of image sensor irradiation damage on the tracking and pointing accuracy of optical communication system

卫星光通信系统中的图像传感器在空间辐射环境中会因辐射损伤导致成像噪声增大,从而在确定光斑质心时产生偏差,影响系统跟瞄精度。文章基于典型器件地面辐照试验数据分析结果,利用灰度质心算法对不同尺寸模拟缺陷光斑的质心偏差量进行计算,并分析质心偏差对系统跟瞄精度的影响。结果表明:光斑的质心偏移与辐射产生缺陷像素的数量和位置均相关;增大光斑尺寸可减小质心偏差。最后,从抗辐射损伤能力角度为系统光斑尺寸选取提出约束条件要求。

The image sensor in the optical communication for satellite may produce noise due to the spaceirradiation damage,which leads to the deviation in determining the light spot centroid.Based on the irradiationtest data for typical CMOS devices,different sizes of simulated defect spots are used for calculating the centroiddeviation value by a grey-level centroid algorithm,and the impact on the tracking&pointing accuracy of thesystem is analyzed.It is shown that both the amount and the position of defect pixels caused by the irradiationcontribute to the spot centroid deviation;and the larger the spots,the less the centroid deviation will be.Somesuggestions are made with regard to the constraints for the spot size selection with consideration of the spaceradiation damage.