帮助 关于我们

返回检索结果

基于毛玻璃的全日面太阳像平场测量和改正方法
Flat-field measuring and correction method for full-disk solar image based on ground glass

查看参考文献17篇

王怡然 1   白先勇 1 *   刘四清 1   邓元勇 2   孙越强 1  
文摘 全日面太阳光球像和色球像是监测太阳活动的主要数据,对望远镜观测的原始图像进行平场改正是数据处理过程中的基础工作.本文尝试利用毛玻璃测量全日面太阳光球和色球像的平场,通过理论模拟和实地测量验证了该方法的有效性.首先,模拟计算了太阳经毛玻璃扩散后在观测视场内形成的面光源的均匀性,其均匀度为99%,可以用来测量平场.其次,在全日面太阳光球和色球望远镜上的实验结果表明,本方法获得的平场像能够改正原始观测像中高频的脏点和光路不均匀性,因平场观测和常规观测图像中杂散光影响不同,导致平场改正像存在低频失真,但可通过理论临边昏暗图像对平场改正像进行低频信息修正.修正后的平场改正像与理论临边昏暗像相关系数达到0.99以上.最后,以HMI发布的光球像和GONG发布的色球像作为参考像,选取活动区所在小视场和宁静区大视场,分别与利用本方法实验改正后的光球像和色球像进行了结构相似度等方面的量化对比.对比结果表明,改正像的各项指标均优于原始像.本文提出的平场测量和改正方法简便易行,且容易实现自动化测量,为全日面太阳望远镜的平场测量和改正提供了新方法.
其他语种文摘 Full-disk solar chromosphere and photosphere images are mainly used for monitoring solar activities. Flat-field correction of observation image is a basic work during data processing. In history, it is difficult to obtain uniform area light whose intensity is similar as sun. So flat-field measurement and correction of full-disk solar image usually depend on moving images and mathematical calculation. In order to overcome some disadvantages of traditional methods, such as large calculating quantity, complicated algorithms and difficult to realize automation, we research and design a new flat-field correction method based on ground glass. In this text, sunlight diffused by ground glass in field of view is used as uniform area light for flat-field measuring. We simulated the area light that sun diffused by ground glass, calculated the uniformity of area light in field of view. The uniformity of area light is more than 99%, so it can be used as uniform area light for flat-field measurement directly. We designed flat-field measurement device and formulate steps and methods for flat-field correction. After numerical stimulation and calculation, experiments carried out on solar chromospheres telescope and photosphere telescope separately. The result shows that the flat field obtained in this text could correct high-frequency information such as spots and non-uniformity of light path. Subjected to telescopes limited ability to eliminate stray light, flat-field measurement and correction also causes low-frequency information anamorphous because the angle of diffused light is much larger than normal observation. In order to amend low-frequency information distortion, we use multi-scale morphology filtering and median filtering to extract the low-frequency image from flat-field corrected image. Then the extracted low-frequency image is amended on the basis of theoretical limb darkening image. After flat-field correction and amendment, the correlation coefficient between corrected image and theoretical image is more than 0.99. At last, photosphere image of HMI and chromospheres image of GONG are used as reference images to quantitatively evaluate corresponding result in various field of view. The preprocessing of reference images includes three steps: (1) Centralization and geometric correction of experiment images and reference images; (2) unify reference images' pixel resolution based on experiment images; (3) according to fitting intensity attenuation of experiment images' margin, convolve the same Gaussian profile to unify the atmosphere effect on reference images and experiment images. The evaluation result shows that all indexes of corrected image are better than that of origin images. The flat-field measurement and correction method in this text is simple and convenient, and it is easy to realize automation. We suggest that the above mentioned method can be considered as a new method for full-disk solar telescope flat-field measurement and correction. In the future, we need to use diffuser which output angle is smaller during flat-field measurement to shorten exposure time and narrow the exposure time difference between flat-field measurement and normal observation. If a full-disk solar telescope wants to use this method to measure and correct flat-field, the ability of stray light elimination must be considered and optimized during design stage, and the data processing would be more simple and easy.
来源 科学通报 ,2017,62(26):3057-3066 【核心库】
DOI 10.1360/N972016-01477
关键词 毛玻璃 ; 太阳望远镜 ; 平场测量 ; 图像处理 ; 空间环境
地址

1. 中国科学院国家空间科学中心, 北京, 100190  

2. 中国科学院国家天文台, 北京, 100012

语种 中文
文献类型 研究性论文
ISSN 0023-074X
学科 天文学
基金 国家自然科学基金
文献收藏号 CSCD:6087234

参考文献 共 17 共1页

1.  总装备部电子信息基础部. 太阳风暴揭秘,2012:5-6 被引 1 次    
2.  Deng Y. Reports on test observations with the multi-channel solar telescope. Sol Phys,1997,173:207-221 被引 3 次    
3.  刘煜. 国内首架日冕仪落户云南丽江. 天文爱好者,2014,1:60-63 被引 3 次    
4.  Haldeman B J. Lambert: A novel compact calibration solution for superior telescope flat fielding. Proc SPIE. 7014,2008:701420 被引 1 次    
5.  Marshall J L. Flattening scientific CCD imaging data with a dome flat-field system. arXiv: astro-ph/0510233,2005 被引 1 次    
6.  Stetson P B. CCD photometry of the globular cluster M92. Astron J,1988,96:909-975 被引 1 次    
7.  Kuhn J R. Gain calibrating nonuniform image-array data using only the image data. Publ Astron Soc Pacific,1991,103:1097-1108 被引 16 次    
8.  Chae J. Flat-fielding of solar magnetograph observations using relatively shifted images. Sol Phys,2004,221:15-21 被引 6 次    
9.  Xu G G. Flat-fielding of solar Hα observations based on the maximum correntropy criterion. Astron J,2016,827:137 被引 1 次    
10.  Denker C. Synoptic Hα full-disk observations of the sun from big bear solar observatory-I. Instrumentation, image processing, data products, and first results. Sol Phys,1999,184:87-102 被引 5 次    
11.  周海宪(译). 现代光学工程,2011:185-186 被引 1 次    
12.  . Quantities and Units GB3100-3102-93. National Standardization Technical Committee,1994 被引 1 次    
13.  Coughlin M. A collimated beam projector for precise telescope calibration. Proc SPIE. 9910,2016:99100V 被引 1 次    
14.  Yang Y. Detection and restoration of non-radial variation over full-disk solar images. J Korean Astron Soc,2013,46:191-200 被引 2 次    
15.  Feng S. Automated detecting and removing cloud shadows in full-disk solar images. New Astron,2014,32:24-30 被引 5 次    
16.  Neckel H. Solar limb darkening 1986-1990 (λλ303 to 1099 nm). Sol Phys,1994,153:91-114 被引 3 次    
17.  Wang Z. Image quality assessment: From error visibility to structural similarity. IEEE Trans Image Process,2004,13:600-612 被引 2018 次    
引证文献 2 篇

1 白先勇 利用太阳自转提取全日面太阳望远镜的平场和偏振本底 科学通报,2018,63(3):301-310
被引 2 次

2 白先勇 利用工程散射片测量太阳光谱观测设备的平场 中国科学. 技术科学,2019,49(8):910-918
被引 0 次

显示所有2篇文献

论文科学数据集
PlumX Metrics
相关文献

 作者相关
 关键词相关
 参考文献相关

版权所有 ©2008 中国科学院文献情报中心 制作维护：中国科学院文献情报中心
地址：北京中关村北四环西路33号 邮政编码：100190 联系电话：(010)82627496 E-mail:cscd@mail.las.ac.cn 京ICP备05002861号-4 | 京公网安备11010802043238号