反射式光学像面拼接方法研究

Reflector Mirror Based Optical Butting

目前,电荷耦合图像传感器的像面尺寸不足以满足现代空间光学系统的需求,本文采用反射式光学系统拼接的方法来扩大光学系统的视场.针对光学拼接带来的渐晕和使调制传递函数变小的问题,研究了一种带有6个反射面的反射镜光学拼接系统,分析了反射镜拼接系统渐晕的特点,提出采用子子像面间渐晕补偿法消除子像面交界处的渐晕,并对像面边缘的渐晕进行补偿.另外,通过合成点扩散函数法来改善光学拼接系统的调制传递函数,结果表明:合成图像的调制传递函数与子图像的调制传递函数相比,虽然截止频率没有提高,但在同一频率处的值有明显的提高.

The size of a single CCD cannot meet the requirements of modern optical system. To enlarge the field of optical system, a reflector based butting system was adopted. Aiming at the problems of vignetting and decline of modulation transfer function caused by butting, a reflector based butting system which has 6 reflectors was investigated. By analyzing the feature of vignetting, a sub-image pixel overlapping method was proposed to reduce the vignetting. At the same time, vignetting at edge was restored, and the modulation transfer function was improved by compositive point spread function. The results show that though the cut-off frequency has not been increased, the value of modulation transfer function is improved obviously.