论文标题
一种改进的方法，用于估计冠状动脉传播干扰的速度场
An improved method for estimating the velocity field of coronal propagating disturbances
论文作者
论文摘要
太阳能电晕寄托着连续的传播干扰（PD）。这些在电晕的广阔地区，包括安静的太阳。本文的目的是提出一种改进的，有效的方法，以创建速度向量场图，基于PD的方向和大小，如PD的方向和大小，如极端紫外线（EUV）图像的时间序列中所观察到的那样。此处介绍了该方法，用于与大气成像组件（AIA）/太阳能动力学观测站（SDO）EUV通道一起使用，并在最高12S节奏下作为输入\ App2小时的图像。提取了来自磁盘中心附近区域的数据，并将一个称为时间归一化的过程应用于共对准数据。使用\ trous \分解降低噪声后，有效地揭示了PD。然后，使用修改的Lucas Kanade算法来绘制速度字段。此处描述的方法在几分钟内在台式计算机上舒适地运行，与先前的实施相比，效率的数量级提高了。应用于安静的太阳区域，我们发现速度场描述了典型的50至100 \ arcsec \（36至72mm）的典型尺寸为50至100 \ arcsec \典型的外向PD流的镶嵌物。流量来自细胞中心的点和狭窄的走廊，并以细胞之间的狭窄边界结束。与紫外线AIA图像的视觉比较表明，流源与明亮的光滑超晶体网络边界相关。假设PD遵循局部磁场，则速度流场是冠状磁场平面分布的代理，因此地图为电晕拓扑提供了独特的见解。这些对于安静的太阳区域特别有价值，在EUV图像中的结构出现很难解释。
The solar corona is host to a continuous flow of propagating disturbances (PD). These are continuous and ubiquitous across broad regions of the corona, including the quiet Sun. The aim of this paper is to present an improved, efficient method to create velocity vector field maps, based on the direction and magnitude of the PD as observed in time series of extreme ultraviolet (EUV) images. The method is presented here for use with the Atmospheric Imaging Assembly (AIA)/Solar Dynamics Observatory (SDO) EUV channels, and takes as input \app2 hours of images at the highest 12s cadence. Data from a region near disk center is extracted, and a process called time normalization applied to the co-aligned data. Following noise reduction using \atrous\ decomposition, the PD are effectively revealed. A modified Lucas Kanade algorithm is then used to map the velocity field. The method described here runs comfortably on a desktop computer in a few minutes, and offers an order of magnitude improvement in efficiency compared to a previous implementation. Applied to a region of the quiet Sun, we find that the velocity field describes a mosaic of cells of coherent outwardly-diverging PD flows, of typical size 50 to 100\arcsec\ (36 to 72Mm). The flows originate from points and narrow corridors in the cell centres, and end in the narrow boundaries between cells. Visual comparison with ultraviolet AIA images shows that the flow sources are correlated with the bright photospheric supergranular network boundaries. Assuming that the PD follow the local magnetic field, the velocity flow field is a proxy for the plane-of-sky distribution of the coronal magnetic field, and therefore the maps offer a unique insight into the topology of the corona. These are particularly valuable for quiet Sun regions where the appearance of structures in EUV images is hard to interpret.
