Precise Proper Motion Measurement of Solar Granulation
Precise Proper Motion Measurement of Solar Granulation
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DOI：
10.1086/166758
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发表时间：
1986-03
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影响因子：
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通讯作者：
L. November;G. Simon;T. Tarbell;A. Title
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文献类型：
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作者：
L. November;G. Simon;T. Tarbell;A. Title
摘要：我们描述了一个强大的互相关技术，用于精确测量的示踪剂上看到的连续图像的太阳颗粒的时间序列的自行。互相关被定义为在图像中的位置的函数，在空间局部化变迹窗口内。空间局部互相关的时间平均值给出了不受大气视宁度偏置的位移的度量。窗口大小和视宁度定义了矢量位移确定的有效分辨率。我们使用这种互相关技术来分析一个80分钟的运行白色光观测在萨克拉门托峰真空塔望远镜。尽管大气视宁度引起的几何畸变比观测到的大尺度太阳位移（100-1000 m/s）瞬间至少大10-20倍，但它对自行80分钟平均值的净贡献是RMS < 20 m/s。测得的矢量位移清楚地显示太阳能mesogranulation和超颗粒流的空间尺度从10分钟到40分钟。这些流量的测量振幅显着大于RMS 100米/秒的噪音，我们主要归因于太阳能颗粒的演变。关键词：太阳大气运动再版。
Abstract : We describe a powerful cross-correlation technique for the precise measurement of the proper motion of tracers seen on successive images of a time series of solar granulation. The cross correlation is defined as a function of position in the image, within a spatially localized apodization window. The time average of the spatially localized cross correlation gives a measure of the displacement that is not biased by atmospheric seeing. The window size and the seeing define the effective resolution of the vector displacement determination. We use this cross-correlation technique to analyze an 80 minute run of white- light observations made at the Sacramento Peak Vacuum Tower Telescope. Even though geometric distortion due to atmospheric seeing is instantaneously at least 10-20 times larger than the observed scale of the large-scale solar displacements, 100-1000 m/s , its net contribution to the 80 minute average of proper motions is RMS < 20 m/s. The measured vector displacement clearly show solar mesogranulation and super-granulation flows having spatial scales from 10 min to 40 min. The measured amplitude of these flows is significantly larger than the RMS 100 m/s noise which we attribute principally to solar granulation evolution. Keywords: Solar atmospheric motion. Reprints.