大视场三线阵航空测绘相机光学系统设计

针对大视场、高分辨率、低畸变和环境适应性要求高的三线阵航空测绘相机光学系统设计要求,开展新型光学系统结构形式设计:首先,根据总体方案要求以及稳定平台安装特点,确定了单镜头的技术方案;接着,分析计算了光学系统各项指标参数,光学系统拉氏不变量达到9.5;然后,对比分析了非像方远心光路、像方远心光路和准像方远心光路的结构形式;最后,设计了一种航空环境适应性良好的双高斯复杂化失对称准像方远心光学系统结构形式。设计的光学系统成像质量好,在全色谱段内的Nyquist频率为100lp/mm,全视场调制传递函数均优于0.36;分别在R、G、B谱段的Nyquist频率为50lp/mm,全视场调制传递函数均优于0.6。光学系统全视场最大相对畸变优于0.1%,在均匀温度0~40℃范围内,全色谱段调制传递函数优于0.3。实验室鉴别率板测试结果表明,相机静态分辨率达到102lp/mm;飞行验证试验结果表明,相机摄影分辨率达到0.16m@2km航高。光学系统设计完全满足大视场三线阵航空测绘相机环境适应性和分辨率的要求。

Optical-system design for large field-of-view three-line array airborne mapping camera

In order to meet the design requirements of the optical system of a three-line array airborne mapping camera with large field-of-view, high resolution, low distortion, and high environmental adaptability, the structural design of a new optical system was developed. First, according to the overall requirements and the characteristics of stable platform installation, a single-lens technical solution was determined. Then, various parameters of the optical system were analyzed and calculated; the Lagrange Helmholtz invariant of the optical system reached 9.5. Then, the structural parameters of the non-telecentric, telecentric, and semi-telecentric optical system light paths were analyzed and compared. Finally, the structure of a complex semi-symmetrical double-Gaussian optical system with good airborne environment adaptability was designed. The designed optical system has good imaging quality. The full field-of-view modulation transfer function is better than 0.36 at a Nyquist frequency of 100 lp/mm in the VIS-spectrum and better than 0.6 at a Nyquist frequency of 50 lp/mm in the RGB-spectrum. The maximum relative distortion of the full field-of-view of the optical system is better than 0.1%. In the uniform temperature range of 0 to 40℃, the full field-of-view modulation transfer function is better than 0.3. The test results of the laboratory gradient resolution board show that the static resolution of the camera reaches 102 lp/mm. The flight verification test results show that the camera photography resolution reaches 0.16 m at 2 km. The design completely satisfies the requirements of environmental adaptability and resolution of the large field-of-view three-line array airborne mapping camera.