推扫式光电成像系统调制传递函数测试装置的设计

 光学遥感系统采用线阵CCD推扫成像方法获取地面景物的高分辨图像信息，调制传递函数(MTF)是评价系统成像质量的重要参数。使用矩形波板作为目标在Nyquist频率处测试光电成像系统的静态调制传递函数可以定量评价系统的成像质量。由于采用线阵CCD推扫成像的光电系统还需要测试其在像移补偿、偏流角控制状态下的动态调制传递函数(Dynamic MTF)，才可以定量评价系统在工作状态下的动态成像性能。为此，论文基于光电成像系统动静态调制传递函数的测试原理，研究了测试系统的组成与工作方法，对其中的平行光管组件与动静态目标发生装置进行了仿真设计。其中平行光管的波像差优于25 nm(RMS)，静态目标发生装置的调焦精度优于3 μm，动态目标发生装置的输出像移补偿偏差小于5/1 000，照明均匀性优于95%，可以理论上实现非相干照明。上述仿真设计结果可以满足新型光学遥感成像系统实验室内动静态调制传递函数的测试需求。

Testing device for modulation transfer function of push-broom electro-optical imaging system

The optical remote sensing system obtains a high resolution imaging of ground targets by the imaging model of linear array CCD push-broom. And the modulation transfer function (MTF) is a key parameter to evaluate the imaging quality of push-broom system. Using the black and white stripe target as a square wave signal of Nyquist frequency to test the static MTF can evaluate the imaging quality of system quantitatively. However, an electro-optical imaging system with linear array CCD push-broom model has to test its dynamic MTF under the image motion compensation and drift angle control condition, and then the imaging quality of system in the real working condition can be evaluated. Based on the theory of dynamic and static MTF testing methods, we studied the constitution and the working principle of testing device, and gave a detail designing for collimator, static and dynamic target generator. The wavefront error of collimator was better than 25 nm (RMS). The focus length adjusting accuracy was better than 3 μm. The output accuracy of image motion compensation was better than 5/1 000. And the illumination uniformity of system was better than 95%, which could realize a theoretic non-coherent illumination. The simulated designing above could satisfy the dynamic and static MTF testing requirement for the new optical remote sensing imaging system in laboratory.