Data sources from 1969 to 2000: 1:100000 aerial topographic map of yuzhufeng area in 1969 (resolution of 50m), and SRTM data of 2000 (resolution of 30m). Data sources for 2000-2012: SRTM data in 2000 (resolution of 30m), and DEM generated by TanDEM-X / TerraSAR-X radar interferometry in 2012 (resolution of 10m).

Before the calculation of glacier surface elevation changes, 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, the plane and elevation are corrected by using the cosine relationship between slope aspect and elevation difference. Then, the relationship between the maximum curvature and elevation difference is used to reduce the error caused by different resolutions. The DEM registration and relative accuracy evaluation of the two periods are carried out, and the glacier elevation changes in different periods are obtained