A digital elevation model, also known as a DEM, refers to a geospatial dataset that represents the three-dimensional surface of the Earth or any other celestial body in digital form. It provides information about the elevation or height of the terrain at different locations or points within a specific geographic area.
A DEM consists of a grid or matrix of regularly spaced elevation values, typically represented as a raster dataset, where each cell or pixel contains a numerical value representing the elevation. These values can be either absolute heights above sea level or relative heights with respect to a reference point.
DEM data is derived from various sources, such as satellite sensors, LiDAR (Light Detection and Ranging) technology, or radar systems. These data sources use different techniques to measure the elevation, including bouncing laser beams or radar signals off the Earth's surface and recording the time it takes for the signal to return.
DEM datasets have numerous applications in various fields, including cartography, hydrology, geology, environmental science, urban planning, and engineering. They play a crucial role in creating accurate maps, analyzing terrain characteristics, modeling water flow and drainage patterns, identifying potential landslide or flood-prone areas, designing infrastructure, and conducting topographic analysis. DEM data can also be combined with other remote sensing data layers, such as satellite imagery, to create comprehensive geospatial models for further analysis and visualization.
