Ice velocities of Hagen Glacier, Greenland derived from Landsat feature tracking

Ice velocities from Hagen Glacier derived from Landsat using the ImGRAFT feature tracker. ----------------------------------------------------------------------------------------- Processed by Aslak Grinsted 2018 For a project lead by Anne Solgaard The folder contains a matlab file for each image pair. The filenames has the form: V_Hagen_[Ayear][Ajulianday]-[Byear][Bjulianday]_[path][row] Each file has these variables: tA: A matlab datenum for sceneA tB: A matlab datenum for sceneB fA: filename of scene A fB: filename of scene B px: [98×168 double] Grid of Easting coordinates py: [98×168 double] Grid of Northing coordinates Ia: geotiffinfo of sceneA - contains projection information Ib: geotiffinfo of sceneA - contains projection information dt: days between scene A and B C: Simililarity score of templatematch (see help on imgraft templatematch function) Cnoise: Background similiarity score of templatematch snr: C/Cnoise options: Options for ImGRAFT templatematch function (see help on imgraft templatematch function) dx: Easting displacement (already divided by dt) dy: Northing displacement (already divided by dt) lat: Geographical coords for px,py lon: Geographical coords for px,py The displacements have not been corrected for bad georeferencing. The ice velocities has been extracted along a flowline and corrected for bare rock displacement. These data can be found in the file: hagen-aslakVs.mat. This file contains these variables: AnneLine: definition of flowline Vextract: Velocities along flowline. The first two columns hold the datenums of scene A and scene B. dist: distance along line xline: projected coordinates of line

基于Landsat卫星影像、使用ImGRAFT特征追踪器（ImGRAFT feature tracker）提取的哈根冰川（Hagen Glacier）冰流速数据。
-----------------------------------------------------------------------------------------
该数据集由Aslak Grinsted于2018年完成处理，项目由Anne Solgaard牵头。文件夹内包含每一组影像对对应的MATLAB文件，文件名格式为：`V_Hagen_[A年][A儒略日]-[B年][B儒略日]_[轨道号][行号]`。每个文件包含以下变量：
`tA`：场景A的MATLAB日期序号
`tB`：场景B的MATLAB日期序号
`fA`：场景A的影像文件名
`fB`：场景B的影像文件名
`px`：[98×168 double] 东向坐标网格
`py`：[98×168 double] 北向坐标网格
`Ia`：场景A的GeoTIFF元信息，包含投影参数
`Ib`：场景A的GeoTIFF元信息，包含投影参数
`dt`：场景A与场景B之间的天数间隔
`C`：模板匹配相似度得分（详见ImGRAFT特征追踪器模板匹配函数帮助文档）
`Cnoise`：模板匹配的背景相似度得分
`snr`：信噪比，即`C`与`Cnoise`的比值
`options`：ImGRAFT特征追踪器模板匹配函数的参数设置（详见对应帮助文档）
`dx`：东向位移（已除以时间间隔`dt`）
`dy`：北向位移（已除以时间间隔`dt`）
`lat`：对应`px`、`py`网格的地理纬度坐标
`lon`：对应`px`、`py`网格的地理经度坐标

上述位移数据未针对不良地理配准进行校正。冰流速数据已沿冰流流线提取，并针对裸岩位移进行了校正，相关数据存储于文件`hagen-aslakVs.mat`中。该文件包含以下变量：
`AnneLine`：冰流流线的定义
`Vextract`：沿冰流流线提取的流速数据，其前两列分别为场景A与场景B的日期序号
`dist`：沿流线的累计距离
`xline`：流线的投影坐标