(n) A 3-D computer model of a land form generated from survey data. Such models are often used by civil engineers and land planners to explore possible placements of structures or changes to the terrain before actual construction begins.

Digitally encoded information about the elevation (or variation of relief) of a given area. This gives a quantitative model of landform. Often the terms DEM (Digital Elevation Model) and DTM (Digital Terrain Model) are used interchangeably, although many prefer to use the term DEM to describe a model containing only discrete data on elevation.

A topographic surface or computer representation of terrain stored in a digital data file as a set of 3-dimensional ("x,y,z") coordinates. The image may be displayed on a computer monitor or portrayed on a map. Also called a digital elevation model (DEM).

A data model that attempts to provide a three dimensional representation of a continuous surface. Often used to represent relief.

a digital representation of part of the earth's surface

a grid of height measurements showing the elevation of the land surface above sea level, shown as a brightness image on the far left, where bright areas represent higher land

a mathematical representation of the shape of the surface of the Earth, its topography

a means of storing data which collectively defines the form of a portion of the earth's surface

land surface representation in digital form by an elevation grid or list of three-dimensional coordinates.

Digital Terrain Model is a sample of terrain elevations points used to model a land surface. It is a required element in the processing of digital orthoimagery based on the accurate identification of control points in the images whose ground positions are accurately known.

A more rigorous 3-D model of the Earth's surface than a DEM. A DTM can be used for accurate contour modeling and can also be used for orthorectification.

A digital model of the terrain surface - similar to a DEM but often enhanced by planimetric information

Gridded representation of terrain height above sea level.

a numerical model of the Earth's surface.

A computer graphics software technique for converting point elevation data into a terrain model displaced as a contour map, sometimes as a three-dimensional "hill and valley" grid view pf the ground surface.5

A three-dimensional model of the Earth's surface, provided in digital form.

a land surface represented in digital form by an elevation grid or lists of three-dimensional coordinates.

See digital elevation model.

a Three-dimensional model of digital elevation data (DEM - see previous definition) for cartographic representation. Terrain models are often displayed as grids, superimposed over topography maps to illustrate peaks and valleys.

A digital terrain model (DTM) is a topographic model of the bare earth that can be manipulated by computer programs.