What is Digital Elevation Model（DEM）？

Apr 07, 2023

A digital elevation model (DEM) is a digital representation of the topography of a geographic area. It is a type of geographic data that encodes the height and slope of terrain on a raster at regular intervals, usually using a raster data format. DEM are commonly used to create digital maps and to perform spatial analysis of terrain and other geographic features.

There are several different types of DEM based on the resolution and accuracy of the data.Some common types of DEM include:

● Digital Terrain Model (DTM): This digital elevation model represents bare earth terrain without vegetation or other surface features.

● Digital Surface Model (DSM): This DEM represents the top of the Earth's surface, including vegetation, buildings, and other objects.

● Digital Terrain Elevation Data (DTED): A DTED is a DEM created using elevation data from satellite imagery or other sources.

We can create DEM using a variety of methods, such as interpolating contour lines from topographic maps, digitizing elevation data from aerial photographs or satellite imagery, or direct measurements using lasers or other sensors. DEM have resolutions ranging from millimeters to hundreds of meters, depending on the data source and intended application.