The details of the peaks and valleys in the terrain will be better modeled with small grid spacing than when the grid intervals are very large. For more detailed the information in DEM data file, it is necessary that grid points are closer together. The intervals between each of the grid points will always be referenced to some geographical coordinate system (latitude and longitude or UTM (Universal Transverse Mercator) coordinate systems (Easting and Northing). DEM data files contain the elevation of the terrain over a specified area, usually at a fixed grid interval over the “Bare Earth”. In a DEM, each cell of raster GIS layer has a value corresponding to its elevation (z-values at regularly spaced intervals). Digital Elevation Model (DEM)ĭigital Elevation Models (DEMs) are a type of raster GIS layer. Down the line you fill find out what is DEM, DTM and DSM and difference among DEM, DTM and DSM. In this article I am trying to provide a clear understanding about DEM, DTM and DSM. The term Digital Elevation Model (DEM), Digital Terrain Model (DTM) and Digital Surface Model (DSM) has several meanings and are not always understood properly, correctly or misinterpreted.
