针对暗目标的帧转移面阵CCD成像系统设计  

Design of Frame Transfer Area CCD Imaging System for Dark Objects

作　　者：张玉衡[1,2] 颜毅华[1] 

机构地区：[1]中国科学院国家天文台太阳活动重点实验室,北京100012 [2]中国科学院大学,北京100049

出　　处：《天文学报》2015年第3期295-304,共10页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11221063)资助

摘　　要：为了实现在深空探测中对暗弱天体目标的低噪声观测要求,提出了一种稳定简单的空间相机成像系统的设计方法.基于英国E2V公司的背照式帧转移面阵CCD(CCD47-20AIMO),给出了系统各组成部分的电路设计原理.其中相关双采样型模拟-数字转换器(AD)和动态存储器(SDRAM)的运用可以有效抑制图像信号中的相关噪声.此外,还提出了便于调整曝光时间的驱动控制方法,将感光阶段的曝光时间独立出一个可调延时,使成像系统更适于长曝光时间的调整要求.成像系统采用Altera公司的CycloneⅢ系列的EP3C25Q240C8型现场可编程门阵列(FPGA)作为核心控制器件,驱动的编写按照各器件功能进行模块化设计,具有很强的可移植性.对成像系统的各时序端进行的仿真和实测结果表明驱动电路工作正常,系统设计符合预期要求.TO realize the requirement of low-noise observation of the dark objects in deep-space missions~ a simple and stable design method for the imaging system of space camera is proposed in this paper, and it is performed for the schematic circuit diagram design of each part of the CCD47-20 back illuminated AIMO produced by E2V company. The long exposure for the dark object observation can be realized by adjust- ing the delay time. The imaging system circuit uses the synchronous dynamic random access memory （SDRAM） and correlated double sampling （CDS） analog-to-digital con- verter （AD） which can remove the noise in the image signal. The Altera＇s CycloneIII EP3C25Q240C8 field programmable gate array （FPGA） is adopted as the core con- trol device in the imaging system to write the driver, which is modularly designed and portable as well. The simulation and measurement show that the drive circuit works normally to satisfy the requirement of systematic design.

关 键 词：航天器 仪器 

分 类 号：P111[天文地球—天文学]