This data set is aimed at Gangri Gabu area in the eastern section of nyainqentanglala. The data content includes the glacier surface elevation changes in gangrigab area from 1980 to 2000 and from 2000 to 2014, including two data files, and the data format is GeoTIFF format. The data set contains two GeoTIFF files, i.e., 1980-2000 glacier surface elevation change and 2000-2014 glacier surface elevation change. Each GeoTIFF file is a single band file, which contains the change of glacier surface elevation in gangrigab area in corresponding period. The spatial reference of data files is utm-47 / WGS-84 coordinate system, with spatial resolution of: elevationchange1980-2000.tif, spatial resolution: 25m; elevationchange2000-2014.tif, spatial resolution: 10M.
|collect time||1980/01/01 - 2014/12/31|
|collect place||Gangri Gabu|
|data size||20.1 MB|
1980 to 2000 Data sources: 1:50000 aerial topographic map digitization results of Gangri Gabu area in 1985, and SRTM data (resolution of 30m) in 2000. 2000-2014 Data sources: SRTM data in 2000 (resolution of 30m), and DEM generated by TanDEM-X / TerraSAR-X radar interferometry in 2014 (resolution of 10m).
Before the calculation of glacier surface elevation change, the multi-functional DEM corrector is used to repeatedly register and correct the DEM of the two periods involved in the calculation, so as to ensure that the two have the unified elevation datum and the lowest coordinate deviation, and then obtain the optimal glacier surface elevation change results. The resolution of the data set is selected according to the highest resolution of the DEM in the two periods involved in the difference. The difference between the lower resolution DEM and the higher resolution DEM is determined by bilinear interpolation method, and then the interpolation calculation is carried out to ensure that the difference results can reflect the changes of glacier surface elevation in two periods more precisely and accurately.
After checking the accuracy of DEM in different periods, we use the cosine relationship between slope aspect and elevation difference to carry out plane and elevation correction; then we use the relationship between maximum curvature and elevation difference to reduce the error caused by different resolutions, carry out registration and relative accuracy evaluation on the two periods of DEM, and get the glacier elevation changes in different periods.
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