为了降低多波段全天空成像仪的复杂度和研制成本, 提出了一种免调焦、高鲁棒性的多波段全天空成像光学系统方案.采用像方远心鱼眼镜头加物方远心像方准远心的有限共轭距成像镜组成二次成像系统, 货架级的窄带滤光片置于一次像面处, 使用H-FK61和KF2两种玻璃实现全系统复消色差.设计结果表明：系统F数为2.8, 波段范围427.8~865 nm, 色焦移小于0.048 mm, 系统8个观测通道的光学传递函数都在0.46以上, 满足使用要求, 且滤光片公差容限非常宽松, 面形公差PV≤λ/2、折射率公差±0.003、厚度公差±0.05, 货架级产品即可满足使用要求.相比传统方案, 该系统省去了探测器调焦机构、且不需要使用定制的窄带滤光片, 达到了简化系统降低成本的目的.

In order to reduce the complexity and development cost of the multi-band all-sky imager, a multi-band all-sky imaging optical system with no focusing and high robustness is proposed. A secondary imaging system is composed of a telecentric fisheye lens and a finite conjugate distance imaging lens of the telecentric image. The shelf-level narrow-band filter is placed at the image plane, using H-FK61 and KF2 glasses achieve full system apochromatic. The design results show that the system F number is 2.8, the band range is 427.8~865 nm, the chromatic focal shift is less than 0.048 mm, and the optical transfer functions of the eight observation channels of the system are all above 0.46, which meets the application requirements. The tolerance of filter is very loose. The surface tolerance PV is less than λ/2, the refractive index tolerance is ±0.003, the thickness tolerance is ±0.05, and the shelf-level products can meet the application requirements. Compared with the traditional scheme, the system eliminates the detector focusing mechanism and does not need to use a customized narrow-band filter, which simplifies the system and reduces the cost.