基于天基光学探测图像初析南大西洋异常区影响

文章针对目前在轨运行的高灵敏度探测类可见光遥感器经过南大西洋异常区（SouthAtlanticAnomaly，SAA）时出现的探测能力降低、目标无法识别等现象，通过卫星在轨获取的SAA天基探测图像研究图像中出现的异常现象机理；提出了基于CCD探测器固有暗像元区的图像特征变化开展SAA影响评估的方法，根据在轨图像暗像元区的均值和标准差、图像区的热像素及活像元等特征参数的统计分析，判断经过SAA过程中连续获取的图像中出现显著影响时的拐点，通过曲线拟合估算出该轨道高度的SAA空间分布特征和边界，依此进一步提出利用在轨天基探测图像给出测量影响该轨道高度卫星SAA区域边界的简单方法；最后，基于SAA对天基探测器件的影响分析结果和认识，给出了高灵敏度探测类卫星避免或消除SAA影响的改进措施和建议。文章采用的数据分析和评估方法为提升SAA对天基探测影响的认识，以及下一步有效开展空间碎片探测工作提供参考。

Analysis of Influence of South Atlantic Anomaly Based on Space-based Visible Detection Images

When the in-orbit high sensitivity detection visible sensor passes through the south Atlantic anomaly（SAA）region，its detection capability is weaken and unable to identify the target. Based on the space-based visible detection images collected by the satellites in SAA，the principle of anomalies was analyzed. And a evaluation method of SAA area influence was developed，based on the image character change of CCD detector in dark pixel areas. According to the statistics and analysis of the dark pixel areas image character parameters，such as mean，standard deviation，hot pixel and living pixel number，et al. The inflexion of continuous images occurring significant influence was estimated. The multiplication curve fitting was used to compute the spatial distribution and border of SAA area. Then a simple method was proposed to measure the SAA border, which has a significant influence on the operating satellites in this orbit altitude. Finally, to avoid the SAA area influence on high sensitivity detection satellite, the improvement measures and recommendations were given according to the analysis results. The data analysis and evaluation method will provide the foundation for future work on space debris detection.