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题名	太阳多通道高分辨重建方法研究
作者	姚绘玲
学位类别	硕士
答辩日期	2014-04
授予单位	中国科学院研究生院（云南天文台）
授予地点	北京
导师	金振宇
关键词	多通道重建 PSF修正 波前探测 退卷积 大气色散
其他题名	The study of the Solar Multi-channel High Resolution Reconstruction Method
学位专业	天文技术与方法
中文摘要	研究太阳光球和色球上更精细的结构，需要获得高空间分辨率的图像，大气湍流的存在使得大型地面望远镜无法实现衍射极限成像。为克服湍流获取高分辨率的图像，NVST选用应用较广泛的高分辨统计重建技术。高分辨统计重建技术简单易实现，但是计算量大，尤其是对多通道进行同步采集的太阳望远镜，数据量庞大给后期数据处理造成很大压力，同时Halpha通道由于带宽较窄等原因信噪比较低，会影响高频重建效果，其次其曝光时间（20ms）较长，高频信息被平滑，同样影响重建精度。多通道重建利用单一通道的点扩展函数对其他通道进行重建，能有效缩短数据处理时间，如果我们用信噪比较高的通道去重建信噪比低的通道，也将会在一定程度上提高图像的重建精度。 图像重建的关键是获得精确的点扩展函数（PSF），高分辨统计重建术利用估算的视宁度模拟估算PSF，没有考虑望远镜像差并且高频信息被截止。本文介绍了基于波前探测快速得到PSF的方法，但是由于很难实现对大视场的波前探测等原因，没有采用这种方法。本文提出了一种基于统计重建的结果退卷积得到PSF的方法，此法包含了望远镜的像差和高频信息。获得某一通道的精确PSF后，对其进行波长的修正得到其他波段的PSF，进而实现多通道的重建。文章对多通道的高分辨重建做了模拟实验，并用数值模拟的方法分析了噪声和通道间像差对重建结果的影响。多通道高分辨重建是在所有通道走过相同的大气路径的假设基础上进行的，然而大气色散会使不同波长的光线穿过不同的大气路径，从而使它们受到的大气影响不同。色散引起的这种通道间的波前畸变差异不可避免的会对多通道的重建造成影响，故本文最后对不同观测天顶角下色散对多通道重建的影响做了模拟分析。
英文摘要	In order to study the fine structure of solar photosphere and chromosphere, we need to obtain high-resolution images. But the existence of the atmospheric turbulence makes the large ground-based telescope can’t realize the diffraction limited imaging. NVST(New Vacuum Solar Telescope) choose the widely used High-resolution Statistical Reconstruction Method to overcome the influence of atmospheric turbulence, to obtain high-resolution solar images. High-resolution Statistical Reconstruction Technology is easy to implement, but have large amount of calculation, especially for synchronous collection of multi-channel solar telescope, large data quantity gives great pressure on later data processing. For reasons such as narrow bandwidth and so on, halpha channels’ SNR is a little low, this will affect the reconstruction accuracy of high frequency. Simultaneously, its exposure time is long, about 20 ms, and this will smooth high frequency information, thus affect the reconstruction accuracy. Multi-channel reconstruction using the point spread function of a single channel to rebuild other channels, can effectively shorten the data processing time, if we use the high SNR channel to reconstruct the low SNR channel, will also to a certain extent, improve the image reconstruction accuracy. The key of image reconstruction is to obtain the precise point spread function. High-resolution Statistical Reconstruction Method using the estimated seeing parameter to estimate PSF, haven’t consider the aberration of telescopic and have cut-off high frequency information. In the paper we presented a method based on wavefront detection to achive the PSF, but it is difficult to realize in wide field of wavefront detection, then, we proposed another method based on the results of the statistical reconstruction, which containing the telescope aberration and high frequency information. After getting the accurate PSF of a channel, make some correction on the wavelength, and then realize the reconstruction of the multi-channel. We have successfully done the simulation experiment of multi-channel high resolution reconstruction, in addition, analyzed the impact of the noise and the aberration between channels on the reconstruction result. Multi-channel High-resolution Reconstruction was done on the hypothesis that rays of all channels have passed through the same atmospheric path, however, the atmospheric dispersion will make light of different wavelengths pass through different atmospheric paths, so that they are affected by different atmosphere. The differences of the wavefront aberration between these channels caused by dispersion will inevitably affect the result of the multi-channel reconstruction, so, at the last part of this paper, simulation analysis has been done for the impact on multichannel reconstruction under different observation zenith Angle dispersion.
语种	中文
学科主题	天文学
页码	45
内容类型	学位论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/4910]
专题	云南天文台_抚仙湖太阳观测站
推荐引用方式 GB/T 7714	姚绘玲. 太阳多通道高分辨重建方法研究[D]. 北京. 中国科学院研究生院（云南天文台）. 2014.

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