嫦娥三号月基光学望远镜图像中的宇宙线识别  

Identification of cosmic rays in Chang’e’s lunar-based ultraviolet telescope images

作　　者：刘奇[1,2] 王竞 黄茂海[1,2] 魏建彦 LIU Qi;WANG Jing;HUANG Mao-hai;WEI Jian-yan(Key Laboratory of Space Astronomy and Technology,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;Guangxi Key Laboratory for Relativistic Astrophysics,School of Physical Science and Technology,Guangxi University,Nanning 530004,China)

机构地区：[1]中国科学院国家天文台空间天文与技术重点实验室,北京100101 [2]中国科学院大学,北京100049 [3]广西大学物理科学与技术学院广西相对论天体物理重点实验室,广西南宁530004

出　　处：《光学精密工程》2021年第10期2330-2339,共10页Optics and Precision Engineering

基　　金：国家重点研发计划资助项目(No.2020YFE0202100);中国科学院战略性先导科技专项,空间科学基金资助项目(No.XDA15052600,No.XDA15016500)。

摘　　要：宇宙线事件是CCD和CMOS空间探测图像中普遍存在的现象,对目标的识别和提取造成了干扰。对于空间天文观测图像,提出了一种基于天文位置定标的识别算法,并在230帧嫦娥三号月基光学望远镜的CCD图像中,共检测到29731例宇宙线事件。与传统的拉普拉斯算法相比,本算法检测到的宇宙线事件总数多11.14%,多出的部分主要是形态与星像类似的宇宙线事件;在拉普拉斯算法检测到的样本中,98.07%可被本算法检测到;对本算法没有检测到的1.93%样本进行了检查,发现其中48.64%为恒星星像,是错误识别。分析统计了宇宙线事件在月基光学望远镜CCD靶面上的电子沉积分布,和哈勃太空望远镜的两个CCD探测器的结果对比,发现两者形态类似,但前者的峰值略高;进一步分析了宇宙线事件入射角度在CCD靶面上的二维分布,发现在两个方向上有明显超出,可以理解为探测器在嫦娥三号着陆器内部等效铝厚度较小。最后,本文提取出所有识别出的宇宙线事件的形态,建立了“CCD探测器宇宙线实体样本库”,可为空间天文望远镜图像仿真系统提供依据。Cosmic rays interfere with target recognition and extraction and this is a common phenomenon detected in charge-coupled device(CCD)and complimentary metal-oxide semiconductor images taken in space.In this study,we proposed a recognition algorithm based on stellar astrometry for space astronomical images,enabling us to extract a total of 29731 cosmic-ray events in the 230 CCD images taken by the Chang'e-3 Lunar-based Ultraviolet telescope(LUT).On the one hand,this number was 11.14% more than the one detected by traditional Laplace algorithm,which was primarily because of events detected with a shape similar to a star.On the other hand,our algorithm failed for only 1.93% of the cases detected by the Laplace algorithm.Among these failed cases,48.64% were stars,indicating misidentification by the Laplace algorithm.In addition,although peaks appeared at a higher value,the distribution of the electron deposition on the LUT CCD was comparable with those reported for the two Hubble Space Telescope CCDs.With a two-dimensional distribution of the incident angle of cosmic rays on the CCD surface,we identified significant excesses in two directions,which could be understood by a smaller equivalent aluminum thickness of the Chang'e-3 lander.Finally,we built a public library of cosmic rays recorded by the LUT CCD by extracting the patterns of all the detected cosmic rays,which might be useful for future space telescope image simulation systems.

关 键 词：月基光学望远镜 电荷耦合器件 宇宙线 天文位置定标 天光背景拟合 

分 类 号：TP751.5[自动化与计算机技术—检测技术与自动化装置] P184.5[自动化与计算机技术—控制科学与工程]