摘要
在空间调制型哈达玛变换光谱成像仪(Space Hadamard Transforms Spectral Imager,SHTSI)中采用数字微镜阵列(Digital Mirror Devices,DMD)作为编码器件,能够使系统实现小型化、轻量化、高分辨率、高帧频成像。但由于DMD的翻转特性,经过DMD编码后的光学成像面发生12°倾斜,导致SHTSI成像光路和制冷型探测器冷光阑不匹配,造成视场缺失和图像降质。针对这一问题,本文提出一种像面预补偿的新型哈达玛编码光谱成像系统设计方法,在前置成像镜组中采用倾斜和偏心的设计,使得一次像面实现24°倾斜,对DMD在调制过程中产生的像面倾斜进行预补偿,从而消除倾斜成像面造成的图像降质问题。基于该方法设计了SHTSI光学系统,系统全视场点列图RMS小于5μm,保证系统在全视场范围内能够均匀成像。根据该设计方案研制SHTSI原理样机,试验结果表明,SHTSI系统满足设计指标,对成像数据进行复原,得到复原光谱角距离评价因子优于0.052。
In a space Hadamard transform spectral imager(SHTSI)system,encoding the template using digital mirror devices(DMDs)can ensure that the system is miniaturized and lightweight,and has high resolution and high frame rate. However,modulation using DMD causes the focus plane of SHTSI to tilt;consequently,the resultant image obtained from the spectrometer does not match the cooled shield of the detector. This causes image degradation and field of view loss. In this paper,a novel SHTSI system design is proposed to improve the quality of the final image. The design also addresses the issues of cold stop aperture mismatch and field of view accuracy. In this scheme,the design of the front lens contains a tilted and off-center lens,which tilts the image of the object by 24° with respect to the primary focus plane. Based on this method,a SHTSI optical system is designed,and the spot diagram RMS of the full field of the system was calculated to be less than 5 μm. This ensures that the system generates an even image. According to this design scheme,a SHTSI principle model machine is developed. The experiment results show that the evaluation of the restored spectral angular distance of the SHTSI system is better than 0. 052.
作者
杨莹
胡炳樑
李立波
王爽
严强强
YANG Ying;HU Bingliang;LI Libo;WANG Shuang;YAN Qiangqiang(CAS Key Laboratory of Spectral Imaging Technology,Xi′an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences,Xi′an 710119,China)
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2022年第6期641-650,共10页
Optics and Precision Engineering
基金
陕西省自然科学基金青年项目(No.2021JQ-323)。
