星载多光谱相机成像系统设计与实现  

Design and Implementation of Spaceborne Multispectral Camera Imaging System

作　　者：叶松[1] 于新宇 甘戈 李扬 邹征宇 路美娜 骆冬根 裘桢炜 Ye Song;Yu Xinyu;Gan Ge;Li Yang;Zou Zhengyu;Lu Meina;Luo Donggen;Qiu Zhenwei(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Sciences,Chinese Academy of Sciences,Hefei 230031,Anhui,China;Key Laboratory of Optical Calibration and Characterization,Chinese Academy of Sciences,Hefei 230031,Anhui,China)

机构地区：[1]桂林电子科技大学电子工程与自动化学院,广西桂林541004 [2]中国科学院合肥物质科学研究院安徽光学精密机械研究所,安徽合肥230031 [3]中国科学院通用光学定标与表征技术重点实验室,安徽合肥230031

出　　处：《光学学报》2023年第24期192-203,共12页Acta Optica Sinica

基　　金：高分辨率对地观测系统重大专项(民用部分)(30-Y20A19-9007-15/17)。

摘　　要：针对卫星上相机对高信噪比、抗辐照等特殊要求,提出一种基于长光辰芯公司的科学级CMOS探测器HR400的多光谱相机成像电子学系统设计,采用FPGA加SRAM缓存的系统架构,重点讨论了CMOS探测器的驱动设计和图像采集技术。首先,针对滤光片轮式多光谱相机曝光时间变化会导致成像偏振方位角差异的问题,提出一种能够根据曝光时间动态调整的延时成像方法,将通道通光中心作为成像的采集中心,保证不同曝光时间下采集的图像中心位置一致且处于最佳采样位置;然后,针对该延时成像方法的成像中心位置误差进行分析;最后,对相机成像性能和不同曝光时间的偏振方位角进行测试验证。测试结果表明:成像系统的时域暗噪声为71.6(等效电子数),当系统光强为饱和光强的80%时,信噪比为588.1,满足载荷成像要求;延时成像方法对由曝光时间导致的偏振方位角差异有明显改善。Objective The components such as water vapor and aerosol in the atmosphere can lead to the blurring of high-resolution satellite remote sensing images,and the image quality will be seriously undermined.By means of multispectral imaging technology,an atmospheric correction instrument and the satellite main camera can obtain the atmospheric parameters in the same region at the same time,and the atmospheric correction for remote sensing images is carried out to improve the image quality.In the field of spectral imaging,CCD detectors are applied by most traditional cameras.However,with the rapid development of technology,CMOS detectors have been able to compete with CCD in terms of quantum efficiency,noise level,dynamic range and other key performance parameters,and have the tendency to gradually replace CCD detectors.To fill the gap of domestic scientific CMOS detectors in the field of space spectral imaging,we design a set of CMOS imaging electronics systems with high reliability and signal-to-noise ratio based on the scientific CMOS detector HR400 of Gpixel for the multispectral imaging requirements of a correction instrument project.Besides,a dynamic time-delay imaging method is proposed according to the characteristics of its filter wheel imaging,which solves the problem of polarization azimuth deviation caused by the variation of exposure time and provides a reference for the design of similar instruments.Methods The system architecture is based on field programmable gate array(FPGA)and static random access memory(SRAM)buffer.The driver design and image acquisition technology of CMOS detectors is discussed in detail.To address the problem that the variation of the exposure time of the filter wheel multispectral cameras will lead to the difference in the polarization azimuth,the influence of the imaging position on the polarization azimuth is analyzed first.Then,combined with the working principles of the rolling shutter CMOS detectors,a time-delay imaging method is proposed,which can be dynamically adjusted acc

关 键 词：成像系统 多光谱相机 CMOS 卫星成像 信噪比 

分 类 号：TP73[自动化与计算机技术—检测技术与自动化装置]