中国激光, 2019, 46 (1): 0110001, 网络出版: 2019-01-27  

TG-2/MAI CCD暗电流特征及其通道依赖性分析与校正 下载: 687次

TG-2/MAI CCD Dark Current Characteristics and Its ChannelDependence Analysis and Correction
作者单位
1 国防科技大学气象海洋学院, 江苏 南京 211101
2 地理信息工程国家重点实验室, 陕西 西安 710054
3 北京应用气象研究所, 北京 100029
摘要
多角度偏振成像仪(MAI)采用背照式面阵CCD探测器, 用于定量获取云与气溶胶参数。暗电流是影响面阵CCD探测器数据质量及其定量应用的主要因素之一。为了分析CCD暗电流特征及其通道依赖性, 并改进CCD成像质量, 在分析MAI 0级数据特征的基础上, 提出基于夜间场景对MAI各通道暗电流特征进行分析的方法, 并于2018年2月2日—16日开展了MAI夜间场景观测实验。通过对比MAI挡光通道白天和夜间的观测结果可知, 白天和夜间观测到的暗电流特征无明显差异。故基于夜间观测数据对MAI 13个通道的暗电流特征开展分析, 结果表明:各通道暗电流分布均存在一定程度的非均匀性及“坏点”, 且单个通道的分布具有较好的稳定性, 但各通道之间存在显著差异。基于图像法对“坏点”进行校正, 基于线性、非性线关系对像元间的不均匀分布进行校正后, 暗电流图像的标准差由12.1%降至6.9%。以晴空洋面观测值为参考, 暗电流及“坏点”对像元观测的最大相对误差由9.1%降至3.0%。分析结果表明:相对于设置暗电流监测通道, 基于夜间观测的暗电流监测不仅可以监测各通道的暗电流特征, 还可以处理暗电流的通道依赖性问题。因此, 在后续的星载观测仪器设计中, 无需单独设置暗电流监测通道就可以直接利用CCD夜间观测对各通道暗电流进行在轨监测与校正。
Abstract
Multi-angle Polarization Imager (MAI) uses a back-illuminated area array CCD detector to quantitatively acquire cloud and aerosol parameters. Dark current is one of the main factors affecting the data quality of the area detector CCD and its quantitative application. In order to analyze the characteristics of CCD dark current and its channel dependence and improve the imaging quality of CCD, based on the analysis of the characteristics of MAI level 0 data, we propose a method for analyzing the dark current characteristics of each channel of MAI based on the nighttime scene. The period from February 2 to 16, 2018, MAI nighttime scene observation experiment is accomplished. Comparing the observations during daytime and nighttime of the MAI light blocking channels, the result shows that there is no significant difference in dark current characteristics observed in daytime and nighttime. Therefore, based on the night observation data, the dark current characteristics of 13 channels of MAI are analyzed. The results show that the distribution of dark current for each channel has some degree of non-uniformity and “bad points”, and the distribution within each channel has good stability, but it is significant difference for each channel. Based on the image method to correct “bad spots”, after correcting the non-uniformity distribution of pixels based on linear, non-linear relationship, the standard deviation of dark current images decrease from 12.1% to 6.9%. Taking the observation of the clear-air ocean as reference, the maximum possible impact of dark current and “bad points” on pixel observations decreased from 9.1% to 3.0%. The analysis results show that dark current monitoring based on nighttime observation can not only monitor the dark current characteristics of each channel, but also handle the channel dependence of dark current relative to setting dark current monitoring channel. Therefore, in the subsequent design of satellite-borne observation instruments, the dark current of each channel can be directly monitored and corrected by nocturnal observation, and there is not necessary to set a dark current monitoring channel separately, which will reduce the design weight of the load.

郭俊杰, 姚志刚, 韩志刚, 赵增亮, 严卫. TG-2/MAI CCD暗电流特征及其通道依赖性分析与校正[J]. 中国激光, 2019, 46(1): 0110001. Guo Junjie, Yao Zhigang, Han Zhigang, Zhao Zengliang, Yan Wei. TG-2/MAI CCD Dark Current Characteristics and Its ChannelDependence Analysis and Correction[J]. Chinese Journal of Lasers, 2019, 46(1): 0110001.

引用该论文: TXT   |   EndNote

相关论文

加载中...

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!