一种地基太阳望远镜焦点探测方法

	一种地基太阳望远镜焦点探测方法
	方玉亮1,2 ; 柳光乾1 ; 金振宇1 ; 李鹏飞1,2 ; 刘忠1
刊名	光学学报(Acta Optica Sinica)
	2017-07
卷号	37 期号:7 页码:133-139
关键词	地基太阳望远镜焦点探测能谱分析大气湍流
ISSN号	0253-2239
其他题名	A Focus Detection Method for Ground-Based Solar Telescope
产权排序	第1完成单位
中文摘要	太阳强热辐射导致太阳望远镜光机系统热形变，引发较明显的时变焦点位置漂移。离焦像差影响高分辨观测，降低观测图像的空间分辨率，因此需要探测并补偿望远镜的离焦像差。由于大气湍流的影响，一般的基于图像处理的焦点探测方法不能有效地运用于地基太阳望远镜。而天文望远镜常用的基于Shack-Hartman 波前探测的方法，在观测太阳边缘和低对比度的太阳米粒结构时无法工作。本文提出了一种基于图像能谱分析的焦点探测方法，该方法以图像能谱比的低频分量的平均值作为焦点探测评价函数，该方法能够消除目标信息的影响和平滑大气湍流的影响。实验证明，该方法的探测精度和探测时间分辨率能满足地基太阳望远镜不同观测目标的高分辨观测的需要。
英文摘要	Intense solar radiation leads to thermal deformation of the solar telescope opto-mechanical system, triggering obvious time-varying focus shifts. Defocus aberration has adverse effect on high-resolution observation, it will reduce the spatial resolution of the image, therefore, it is necessary to be detected and compensated. Considering the effects of atmospheric turbulence, focusing method based on general image processing could not be applied well on ground based solar telescopes. When observing the solar limb and thelow contrast solar granulation, the focusing method based on Shack-Hartmann wavefront sensing that commonly used in astronomical telescopes is invalid. In this paper, a focus detecting method based on power spectrum analysis of images is provided. This method uses the average value of the low-frequency components of the spectrum ratio of the image as the cost function for focus detection, which can effectively eliminate the impaction of object structure and atmospheric turbulence. Experiments show that the sensing accuracy and frequency of this method can meet the requirement of high-resolution observations for different objects on ground-based solar telescope.
学科主题	天文学
分类号	P111
收录类别	EI ; 核心
语种	中文
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/9942]
专题	云南天文台_抚仙湖太阳观测站
作者单位	1.中国科学院云南天文台，云南，昆明，650216 2.中国科学院大学，北京，100049
推荐引用方式 GB/T 7714	方玉亮,柳光乾,金振宇,等. 一种地基太阳望远镜焦点探测方法[J]. 光学学报(Acta Optica Sinica),2017,37(7):133-139.
APA	方玉亮,柳光乾,金振宇,李鹏飞,&刘忠.(2017).一种地基太阳望远镜焦点探测方法.光学学报(Acta Optica Sinica),37(7),133-139.
MLA	方玉亮,et al."一种地基太阳望远镜焦点探测方法".光学学报(Acta Optica Sinica) 37.7(2017):133-139.