altitude datum

The arbitrary level from which vertical displacement is measured. The datum for height measurement is the terrain directly below the aircraft or some specified datum; for pressure altitude, the level at which the atmospheric pressure is 29.92 inches of mercury (1013.2 m.bs); and for true altitude, mean sea level. See also altitude.

Dictionary of Military and Associated Terms. US Department of Defense 2005.

Mentioned in

altitude height
height datum

All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.