- For other senses of this word, see elevation (disambiguation).
The elevation of a geographic location is its height above a fixed reference point, often the mean sea level. Elevation is mainly used when referring to points on the Earth's surface, while altitude is used for points in the air, such as an aircraft. Less commonly, elevation is measured, using the center of the Earth as the reference point. Due to equatorial bulge, there is debate whether the summits of Mt. Everest or Mt. Chimborazo are at the higher elevation, as Mt. Chimborazo is further from the Earth's center while Mt. Everest is higher above mean sea level.
Maps and GIS
A topographical map is the main type of map used to depict elevation, often through use of contour lines.
In a Geographic Information System (GIS), digital elevation models (DEM) are commonly used to represent the surface (topography) of a place, through a raster (grid) dataset of elevations. Digital terrain models are another way to represent terrain in GIS.
To determine elevation of a place, it must be surveyed, in reference to a ground control point.
Topography
The elevation of a mountain usually refers to its summit. The elevation of a hill also refers to the summit. A valley's elevation is usually taken from the lowest point but is often taken all over the valley.
Angle
The elevation (alternately, altitude) angle is the angle above or below the local horizon. Zero elevation is the horizon, straight overhead (zenith) is +90º elevation, and straight down (nadir) is -90º elevation.
See also
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