航空光电成像系统像移补偿技术研究

Image motion compensation technology of aerial photoelectric imaging system

航空光电成像系统由于像移的存在导致成像分辨率下降,严重影响航空光电系统的整机性能。采用像移补偿技术可以提高航空光电系统成像质量。分析了移动探测器像移补偿技术原理与运动光学元件像移补偿技术原理,重点研究了基于快调反射镜(FSM)的高精度像移补偿技术。通过工程简化分析,分别推导了快调反射镜位于平行光路和会聚光路的像移补偿随动角度规律,并针对会聚光路中快调反射镜带来的离焦量进行分析,讨论了离焦量对光学系统波像差的影响。仿真结果表明,随着离焦量的增加,波像差呈线性增大趋势。通过分析光学系统波像差对其光学调制传递函数(MTF)的影响,结果表明F数等于8,在奈奎斯特频率处,当离焦量在0.1 mm以内,光学调制传递函数MTF的下降量在26.6%以内。

Due to the existence of image motion,the imaging resolution of aerial photoelectric imaging system decreases,which seriously affects the overall performance of aerial photoelectric system.The image motion compensation technology can be used to improve the imaging quality of aerial photoelectric system.The principles of image motion compensation technology for mobile detectors and moving optical elements were analyzed,with emphasis on the high-precision image motion compensation technology based on fast steering mirror(FSM).Through the simplified engineering analysis,the law of follow-up angle of image motion compensation of FSM in parallel optical path and converging optical path was deduced,respectively.In addition,the defocus distance caused by the FSM in the converging optical path were analyzed,and the influence of defocus distance on the wave aberration of the optical system was discussed.The simulation results show that the wave aberration increases linearly with the increase of defocus distance.By analyzing the influence of wave aberration of optical system on its optical modulation transfer function(MTF),the results show that the F number is equal to 8,and at the Nyquist frequency,when the defocus distance is less than 0.1 mm,the declining quantity of optical MTF is within 26.6%。