光学系统结构决定了CCD相机的外形尺寸和布局，为保证相机的小型化、轻量化及稳定性,本文针对光学系统设计指标的要求，分析、比较了折射式、反射式及折反射式等光学系统的结构型式，综合考虑相机的空间环境适应性和结构布局等因素，采用像方远心光路，设计了一种兼具匹兹瓦型与对称型优点的新型光学系统结构。设计的光学系统成像质量好，在Nyquist频率为77 lp/mm时，正视相机全视场的平均传递函数为0.613，前、后视相机全视场的平均传递函数为0.578；正视相机畸变为2×10-5，前、后视相机畸变为2.4×10-5。装调完成后对光学系统成像质量进行了检测，各相机光学系统传递函数的测试值均在0.451以上,满足实验室静态传递函数＞0.2，相对畸变＜3×10-4的指标要求。

The size and structure of a three-line array stereoscopic mapping camera are mainly determined by its optical system. To realize the miniaturization, lightening and high reliability of the camera,several kinds of optical system configurations,refraction,reflection and refracting-reflecting optical systems, are analyzed and compared by the requirements of the optical system. In accordance with the environment adaptability and structure layout of the camera,a telecentric system is adopted to design a new optical system to meet the requirement of stereoscopic mapping. The MTF value of each lens in designed optical system is close to the diffraction limit at Nyquist frequency of 77 lp/mm. The distortion of each optical system is less than 2.4×10-5 for the forward and backward sight cameras and 2×10-5 for the straight-sight camera.The tested result shows the MTF of each optical system can reach 0.43 at Nyquist frequency of 77 lp/mm, which is 0.2 higher than a static MTF in laboratory and meets the requirements of the mapping camera for precision.