畸变对TDI成像相机的像移影响研究  

Influence of image motion on TDI imaging camera by distortion effect

作　　者：任秉文[1,2,3] 金光[1] 张元[1] 钟兴[1] 孔林[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所小卫星技术国家地方联合工程研究中心,吉林长春130033 [2]中国科学院大学,北京100049 [3]上海卫星工程研究所,上海200240

出　　处：《红外与激光工程》2014年第12期3951-3957,共7页Infrared and Laser Engineering

基　　金：国家863计划(2012AA121102);国家863计划军口部分(2011AA7026051)

摘　　要：随着时间延迟积分技术(Time Delayed and Integration,TDI)的不断成熟,具有TDI功能的电荷耦合器件(Charge Coupled Devices,CCD)已经广泛应用到高分辨率对地成像系统。然而,采用TDI功能的成像系统在推扫成像过程中必然会受到像移的影响,导致最终成像模糊。主要分析了TDI成像过程中光学系统畸变引起像移的原因,推导了畸变产生像移的数值计算公式,分析了光学系统畸变对TDI成像相机调制传递函数的影响,研究了畸变和像移导致的TDI成像相机图像退化的关系,针对焦距为9 000 mm、积分级次96级、地面像元分辨率GSD=0.6 m,λF/p=1、信噪比为50:1的TDI成像相机,计算了在畸变产生的像移影响下导致的NIIRS(National Imagery Interpretability Rating Scale,美国国家图像解译度分级标准)的变化值ΔNIIRS,计算结果表明在畸变导数值D′(θ)=6.493时引起的ΔNIIRS达到-0.162 4将影响图像的解译需求,最后分析给出了对于该空间相机不影响解译需求的D′(θ)限制条件。可为光学遥感TDI成像系统的设计提供参考。With the Time Delayed and Integration（TDI） technology continues to evolve,Charge Coupled Devices（CCD） with TDI feature has been widely applied to high-resolution earth imaging system.However,in the push-broom imaging process,imaging system using TDI technology would inevitably be affected by the image motion,finally leading to blur image.The reason of image motion caused by optical system distortion in the process of TDI imaging was analyzed,formula of the image motion value was derived,the influence of optical system distortion on Modulation Transfer Function was analyzed,and the relationship between image quality deterioration caused by image motion and distortion was studied.Degradation of National Imagery Interpretability Rating Scale（NIIRS） parameters ΔNIIRS caused by image motion that generated by distortion was calculated for the TDI imaging system of which focal length was 9 000 mm,integral stage was 96,grounding sample distance was 0.6 m,λF/p was 1,SNR was 50 ：1.The results showed when the derivative value of distortion was 6.493,ΔNIIRS would reach-0.162 4,and would affect the image interpretation requirements.Finally,for this space camera,the restriction value of D′（θ） without affecting interpretation requirements was given.This research could provide a reference for optical TDI remote sensing system design.

关 键 词：光学系统 时间延迟积分 畸变 像移 调制传递函数 NIIRS 

分 类 号：TH703[机械工程—仪器科学与技术]