为获得高信噪比的航天遥感图像, 针对CCD成像系统链路分析了影响图像信噪比的主要因素。结合CCD成像系统的响应模型, 明确了系统信噪比的表达式, 并摆脱了具体CCD型号的束缚, 提出了一种"总-分-总"的高信噪比成像电路系统通用设计方法。描述了系统从顶层总体设计、底层各电路模块设计以及全系统联试的完整研制方法。将该方法应用于吉林一号卫星高分辨率多光谱CCD成像电路系统的设计中, 并对成像系统进行了辐射定标试验, 获得了高信噪比的图像数据。结果显示: 在灰度为80%饱和输出时, 获得的全色图像信噪比达到了53.9 dB, 多光谱图像的最高信噪比达到了56.3 dB, 且图像数据经融合后色彩真实、绚丽。本文的CCD成像电路系统设计方法能够为其他航天遥感载荷的电路系统设计提供参考。

To capture the space-borne remote sensing image with a high Signal-to-noise Ratio(SNR), this paper analyses the main factors effect on the SNR of images according to the chain of the CCD imaging system. The expression of SNR in the system was indicated in terms of the response model of CCD imaging system. By avoiding the independency of specific CCD model, a design method of “overall-division-overall” was proposed to implement the CCD imaging circuit with higher SNRs. A completion development method including a top-level design, a module-level design and a total-system test was described. The method was applied in design of the high-resolution CCD imaging circuit system of the Jilin-1 satellite. The radiation calibration experiments for the imaging system was performed and the idea image dada with higher SNRs were obtained. The experimental results indicate that the SNR of panchromatic image is 53.9 dB and that of multispectral image is 56.3 dB when their gray outputs are in the saturation of 80% . Moreover, the fused image shows a real color and magnificent. The proposed method provides references for design of other space-borne CCD imaging circuit systems in remote sensing fields.