多波段空间推扫相机光学系统设计

Optical system design for multi-band push-broom space camera

空间推扫相机的光学系统要求具有大视场、大口径、低F数等特点,据此设计了一种3波段光学系统。在参考国内外各种扫描或推扫相机结构的基础上,根据像差理论和系统要求,采用有效的分光方式和紧凑的光路结构,对不同的波段采用不同的像差校正方法,以及对系统优化组合后,最终得到了一个实用的光学系统。该系统包括可见、中波红外和长波红外波段,视场达到2.93°×0.3,°可见波段的F数为3.8,中波和长波波段的F数为1.9。从设计结果可以看出,系统3个波段的光学调制传递函数(MTF)都接近衍射极限。

A multi-band optical system was designed for the push-broom space camera covering visible,medium infrared and far infrared wavebands. The system has large aperture and low F number due to the requirement of large FOV. With the reference to various scanning and pushbroom cameras at home and abroad, an optimized compact optical system was achieved by an effective beam-splitting approach, in which the aberrations of three channels were corrected respectively according to the aberration theory and system requirement. The field-of-view of the optical system is 2.93°×0.3°, and F number for the visible light is 3.8 while F number for both of medium infrared and far infrared is 1.9. The design result indicates that the optical modulation transfer functions of the three bands within the cut-off frequency are all close to the diffraction limitation.