Digital elevation model¶

A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid.

Version: v1 · 2026-09-28 · History
Domain-specific #: 8970
Domain group: Natural Sciences
Origin domain: Geology & Earth Sciences
Subdomains: Geomatics, Terrain Modeling → Geology & Earth Sciences

Core Idea¶

Digital elevation model is treated here as the recurring formal models and representations identity summarized by this source-grounded definition: A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid.

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The Height Number Grid

A digital elevation model is like a giant grid of numbers where each number tells how high the ground is at that spot. A computer can turn those numbers into a 3D picture of mountains and valleys. People even make them for the Moon and other planets.

Land Heights in a Computer

A digital elevation model, or DEM, is a way of storing the height of land in a computer. It is really a big table of numbers, one height for each spot, and computers turn it into pictures like shaded relief maps. Some versions show the bare ground, called a terrain model, while others include the tops of trees and roofs of buildings, called a surface model. DEMs are made for Earth and also for other planets, moons, and asteroids. People use them for maps, flood planning, and studying the land.

Gridded Elevation Model

A digital elevation model (DEM) is a digital representation of elevation data for terrain or objects on it, commonly for a planet, moon, or asteroid. The model itself is a matrix of numbers, but it is often displayed visually, for example as a relief map, so people can understand it. Terms vary: a digital terrain model (DTM) represents only the bare ground, while a DEM or digital surface model (DSM) may include tree canopy and building roofs. Surface models suit city modeling and visualization, while bare-ground models are needed for flood and drainage modeling, geology, and land-use studies. DEMs are widely used in geographic information systems and are the most common basis for digitally produced relief maps.

A digital elevation model (DEM), or digital surface model (DSM), is a digital, 3D-renderable representation of elevation data for terrain or overlying objects, commonly of a planet, moon, or asteroid. Structurally it is a matrix of elevation values over a spatial grid; a global DEM refers to a discrete global grid. The numbers are typically rendered visually, for example as shaded relief, to make them interpretable. DEMs are standard in geographic information systems and form the most common basis for digitally produced relief maps. Usage distinguishes a digital terrain model (DTM), representing the bare ground surface, from DEMs and DSMs, which may include tree canopy or building roofs. DSMs serve landscape and city modeling and visualization, whereas DTMs are generally required for flood or drainage modeling, land-use studies, geological applications, and planetary science.

Scope of Application¶

Production. This method is still used in mountain areas, where interferometry is not always satisfactory.
Terminology. DEM is often used as a generic term for DSMs and DTMs, only representing height information without any further definition about the surface.
Terminology. In the following, the term DEM is used as a generic term for DSMs and DTMs.
Production. Older methods of generating DEMs often involve interpolating digital contour maps that may have been produced by direct survey of the land surface.
Planetary mapping. A tool of increasing value in planetary science has been use of orbital altimetry used to make digital elevation map of planets.

Clarity¶

A clear use of Digital elevation model names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid.

Manages Complexity¶

Digital elevation model compresses multiple formal models and representations details into a stable diagnostic relation. The source shows both the central mechanism—dTMs are created from high resolution DSM datasets using complex algorithms to filter out buildings and other objects, a process known as "bare-earth extraction".—and the practical consequence—older methods of generating DEMs often involve interpolating digital contour maps that may have been produced by direct survey of.

Abstract Reasoning¶

Type the carrier. Identify the formal models and representations entities to which the claim applies.
State the relation. Use the source-grounded identity: A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid.
Check operation and conditions. The TIN DEM dataset is also referred to as a primary (measured) DEM, whereas the Raster DEM is referred to as a secondary (computed) DEM. 4.

Knowledge Transfer¶

Within the home domain. Knowledge about Digital elevation model transfers literally when a new case preserves the same carrier type, relation, and recognition test. This method is still used in mountain areas, where interferometry is not always satisfactory. DEM is often used as a generic term for DSMs and DTMs, only representing height information without any further definition about the surface. Beyond the home domain. No canonical parent is asserted for Digital elevation model.

Relationships to Other Abstractions¶

Current abstraction Digital elevation model Domain-specific

Parents (1) — more general patterns this builds on

Digital elevation model is a kind of Representation Prime

Digital elevation model is a domain-specific kind of representation under its frozen identity and differentia.

Hierarchy path (1) — routes to 1 parentless root

Digital elevation model → Representation → Abstraction

Neighborhood in Abstraction Space¶

Digital elevation model sits in a sparse region of the domain-specific corpus (88^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (2551 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08