(from the article `altimeter`) ...surface or any object such as an airplane. The two main types are the pressure altimeter, or aneroid barometer, which approximates altitude above ...
Found on
http://www.britannica.com/eb/a-z/r/4
equipment, on board an aircraft or spacecraft, used to determine the height of the aircraft or the spacecraft above the ground, by emission and reception of radio waves NOTE - The term 'ground' means usually the solid or liquid surface of the Earth or the surface of another celestial body.
Found on
http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=713-04-24
No exact match found.
