航天高速TDICCD相机视频信号采样技术  

Sampling Technology on Video Signal of Spaceborne High Speed TDICCD Camera

作　　者：石俊霞[1,2] 郭永飞[1] 司国良[1] 朱宏殷[1,2] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]中国科学院研究生院,北京100049

出　　处：《光电工程》2011年第9期13-18,共6页Opto-Electronic Engineering

基　　金：中科院重大科研装备研制项目

摘　　要：针对航天高速TDICCD相机,为了提高其成像质量,提出了对相关双采样信号进行纳秒级延时的精确采样方法和对驱动芯片的温度漂移进行自适应补偿的方法。首先介绍了相关双采样(CDS)的原理,分析了采样位置对TDICCD相机的影响,然后提出了利用FPGA内部进位链资源实现纳秒级延时从而对采样信号进行精确调整的方法,同时分析了驱动芯片的温度漂移效应导致对CCD输出信号的影响,提出了一种针对温度漂移对采样信号进行自适应调整的方法,来满足采样时序关系。利用实际工程中的成像系统对采样位置精度及高低温环境分别进行了实验。实验结果表明,提出的方法能实现采样信号的精确调整,有效的提高图像的动态范围,同时能对驱动芯片温度漂移进行自适应补偿。未补偿前,在低温度-36℃时图像的信噪比为37.4dB,补偿后图像的信噪比为51dB。In order to improve the image quality of a high speed airborne Time Delay and Integration Charge Coupled Device（TDICCD） camera,a method to precisely adjust the Correlated Double Sample（CDS） signals is proposed.Moreover,a method to compensate the temperature excursion of the driver is proposed.First,the principle of CDS is introduced,and the influence of sample position on a TDICCD camera is analyzed.Then,a method is proposed to adjust the sample signals precisely,which is based on the MUXCY in FPGA.At the same time,the effect of temperature excursion of the driver on TDICCD signal is analyzed,and an adaptive method is proposed to compensate the temperature excursion,which could satisfy the sample timing relationship.Experiments were made from two aspects,which were based on the TDICCD imaging system in our project.One is aimed to the effect of the precision of sample position on imaging quality,and the other is aimed to temperature.Experiment results show that the methods proposed can adjust the sample position precisely,which can improve the dynamic range of an image,and adapt the temperature excursion of the driver.Before compensation,the signal and noise ratio of the image acquired at-36℃ is 37.4 dB.After compensation,the signal and noise ratio of the image acquired at-36℃ is 51 dB.

关 键 词：航天相机 TDICCD 精确采样 温度补偿 

分 类 号：V445.8[航空宇航科学与技术—飞行器设计]