摘要
空间太阳望远镜太阳磁场测量要求图象的信噪比为104.受CCD满阱电荷的限制,必须对CCD采集到的图象,在预处理单元进行图象积分以提高信噪比;为了减小CCD引入的噪声,还采用了CCD图象改正技术;对于宁静态的长时间太阳观测,为了克服图象漂移导致无法进行图象积分的难题,提出了图象相关内插累加技术,来进一步提高信噪比;预处理单元还担负着偏振测量中的Stokes参数归一计算、CCD控制、调焦控制和图象格式化等任务.文中分析了预处理系统的处理功能需求,确定了系统设计方案;采用FPGA加DSP的硬件结构,制作了地面原理样机,开发了系统软件.在地面支持设备上对系统功能进行了仿真和测试.
Signal-to-Noise Ratio （SNR） requirement of Space Solar Telescope is 10^4. At the limits of CCD full well electron numbers,in order to improve SNR, the images collected by CCD must be accumulated in pre-processing unit; CCD image correcting technique was adopted to decrease CCD self-noise;In order to solve image drift,images correlative interpolation accumulation method was brought forward to further improve SNR and to meet design requirement. Pre-processing unit also undertakes tasks as following： Stokes parameter calculation during polarization measurement, CCD control, focusing control and image formattiong. The requirements of pre-processing unit were analyzed,and system design solution was estabhshed. A ground functional prototype was completed according to above scheme with DSP and FPGA as the main chips,and system software was developed. The system function was simulated and testing under ground support equipment.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2005年第7期1291-1294,共4页
Acta Electronica Sinica
基金
国家高技术研究发展计划(863计划)课题(No.863-2.5.1.25)
