轻小型立体相机光学系统研制

Minitype optical system development of stereo camera

针对民用低成本立体成像的应用需求,设计了一种轻小型立体成像相机光学系统,旨在于在250 km轨道高度地面实现像元分辨率为50 m的立体成像,该光学系统在焦面探测器配合下,既可实现立体成像,又可实现大画幅面阵成像。该系统焦距f′=32 mm,视场角2ω=66°,相对孔径D/f′=1：6.8,工作谱段450～750 nm。光学系统设计中,采用反远距系统与消色差显微物镜两种光学结构组合的形式,最终全视场光学传递设计值优于0.49@78 lp/mm,几何畸变小于0.1%,边缘视场与中心视场照度比0.83,边缘视场与主光线入射角小于15°。光学系统采用精密定心装配,并对成像质量进行了检测,装调后相机光学系统传递函数的测试值均优于0.4@80 lp/mm,满足实验室静态传递函数优于0.2的指标。该光学系统在成像幅宽、几何畸变数值等方面的指标均优于国内外典型立体相机。

A minitype optical system used in stereo camera was designed based on civilian low cost stereo imaging requirement, the optical system aimed to achieve 50 m ground sampling distance at 250 km orbit altitude. This optical system can both achieve stereo imaging function and large format array imaging function combined with a CMOS. The system has a focal length of 32 mm, a field of view of 66~, an F-number of 6.8 and a working wavelength range of 450-750 nm. The optical system consists of two parts of optical configurations-retrofocus lens and apochromatic microscope. The system design value of MTF achieves 0.49@78 lp/mm, distortion value less than 0.1%, the relative illumination of marginal field of view achieves 0.83, principal ray incoming angle in image plane of marginal field less than 15%, The testing result after optical mounting centering alignment shows that the MTF of each field of view all achieve 0.4@80 lp/mm,which meets the static MTF requirement in laboratory. This optical system has better performances in imaging width and distortion value compared with other international famous stereo cameras.