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Digital elevation models
Definitions
Elevation models are digital representations of the Earth’s surface. They are used in many applications such as topographic mapping, hydrology, and environmental modeling.
Digital elevation models can be divided into two categories:
- Digital Terrain Model (DTM)
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are bare-earth models that represent the bare ground surface without any objects like buildings and vegetation.
- Digital Surface Model (DSM)
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are models that represent the surface including all objects on it.
Digital elevation models are raster data that cannot be directly represented as triangular meshes. Therefore, they are often converted to triangular meshes using a process called triangulation. The resulting triangular mesh is called a TIN (triangular irregular network).