SAA区对CCD相机探测性能的影响

摘要

我国于2013年7月发射的天基空间碎片探测技术科学试验卫星，其在经过南大西洋异常区(SAA)时，所获取的图像数据出现异常。本文对星上CCD相机分别在非SAA区和SAA区时所拍摄图像的噪声，特别是其中的活像素点噪声和热像素点噪声的变化情况进行了统计分析，并对CCD相机的探测性能受SAA影响程度进行了评估。结果表明，在SAA区所拍摄的图像噪声值较非SAA区增加了5个电子，噪声中包含大量的活像素点和热像素点噪声，由于热像素点的长期存在性，对CCD相机的探测性能产生永久性的损伤。%Our country’s space-based science experiment satellite for debris monitoring was launched in July, 2013. The acquired image data was abnormal when this satellite flying across SAA (South Atlantic Abnormally) region. In this paper, image noise, especially live pixel noise and hot pixel noise in the image obtained by this satellite when flying across non-SAA region and SAA region, was statistically analyzed. Then influence on the CCD detection performance was evaluated. The results show that image noise generated in SAA region is 5 electrons more than non-SAA region. The SAA’s image noise includes plenty of live pixels and hot pixels, and for hot pixels’ longevity, it will generate long term influence on the CCD detection performance.