星载超广角气溶胶探测仪均匀像面性光学设计

Optical Design of Spaceborne Low-distortion and Super-wide-angle Aerosol Imager

为满足空间遥感的迫切需求,设计了星载低畸变超广角气溶胶探测仪系统.系统中多光谱成像仪的光谱范围为0.860～0.965μm,全视场角为94°,相对孔径为1∶4,采用反远距结构,系统后工作距离为42mm.根据反远距结构的像差特点,提出了合理选用易于加工的二次曲面校正畸变,并利用光阑像差产生的有效像差渐晕改善像面照度分布设计方法.运用光学设计软件CODE V和ZEMAX对气溶胶探测仪光学系统进行了光线追迹和优化并对设计结果进行了分析.结果表明,最大畸变为-1.6%,像面上边缘视场的照度大于中心视场照度的46%,光学系统在奈奎斯特频率38.5lp/mm处的光学传递函数均达到0.59以上,完全满足设计指标要求;体积小,适合空间遥感应用;同时证明了设计方法是可行的.

In order to meet the urgent requirements of space remote sensing,a spaceborne low-distortion and super-wide-angle aerosol imager system is designed.The system is a multi-spectral imager with the working wavelength band from 0.860 μm to 0.965 μm,and its full field of view is 94° and the relative aperture is 1∶4.By using a retrofocus structure,its back working is 42 mm in the optical system.Based on the aberration characteristics of retrofocus structure,methods for correcting distortion and improving the illuminance distribution are proposed.Its distortion is corrected by choosing suitable quadric surface,and the illuminance distribution on image plane is improved by using effective aberration vignetting resulted from stop aberration.Ray tracing,optimization and analysis are performed by CODE V and ZEMAX software.The analysis results demonstrate that the maximum distortion is less than-1.6%,and the illuminance at edge field of view is higher than that of 46.9% of central field of view and the MTF is higher than 0.59 at Nyquist frequency 38.5 lp/mm,which satisfies the requirement.Its structure is compact and feasible for space remote sensing.The design method is proved to be feasible.