altitude
The height of a point above or below the sea-level reference, expressed in meters with negative values below it.
The altitude of any point represents its exact location above or below the internationally recognized sea level in meters, expressed in decimals. Numbers below sea level are negative (down to the center of the earth), and numbers above sea level are positive.
Altitude is used in connection with the two geocoordinates (latitude and longitude) to identify each point on earth in three dimensions with respect to the equator, the Greenwich Line, and sea level.
The altitude of a structure is the ground altitude at its precise base, i.e. the point where its height is measured from. This is normally defined as the sidewalk or ground level in front of its lowest exposed perimeter point, not counting points exposed to a surrounding ditch, moat, or trough.
Related definitions
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boundary
The outline of a region or the footprint of a structure, stored as a polygon of geographic coordinates. -
latitude
The distance of any point north or south of the equator, measured in degrees. -
longitude
The distance of any point east or west of the Greenwich line, measured in degrees. -
pinpoint location
The most central balancing point within a boundary or footprint outline. For buildings, use a 'city' field if coordinates are unknown or unclear. -
zoom level
The scale at which an object should ideally appear on a map for optimal viewing.