Global Digital Elevation Models (DEMs) have been utilized in various geomatics\nactivities worldwide. Recently, there exist several available DEMs vary significantly\nin terms of spatial resolution and release dates. This paper examines\nthe reliability of eight recent global DEMs, namely the EarthEnv-D90, SRTM\n1, SRTM 3, ASTER, GMTED2010, GLOBE, GTOPO30, and AW3D30, in two\nstudy areas in Egypt and Saudi Arabia representing different topography patterns.\nKnown ground control points with measured accurate coordinates and\nprecise elevations have been utilized in evaluating the performance of those\nDEMs. It has been concluded that such a judgment procedure should not be\ncarried based on a single statistical measure. First, five statistical measures,\nspecifically the range, standard deviation, correlation, kurtosis, and skewness,\nhave been evaluated separately for each DEM�s errors. Then, a new reliability\nindex is introduced based on the weighted average concept. The accomplished\nresults show that global DEMs perform differently in different topography patterns.\nIt has been concluded that the EarthEnv-D90 and SRTM1 models attain\nhigh reliability indexes in the Nile delta region that represents a flat topography,\nwhile the GMTED2010 and EarthEnv-DEM90 models came in the first\nplaces for the second study area, Makkah, which represents mountainous topography.
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