Altimeter

Science / Weather / Altimeter: An instrument used to determine the altitude of an object with respect to a fixed level. The type normally used by meteorologists measures the altitude with respect to sea level pressure.
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Radar Altimeter

Technology / Radar / Radar Altimeter: A radar altimeter is used by an aircraft to determine its height above terrain. MORE

Pressure Altimeter

Science / Weather / Pressure Altimeter: An aneroid barometer calibrated to indicate altitude in feet instead of units of pressure. It is read accurately only in a standard atmosphere and when the correct altimeter setting is used. MORE

Altimeter Setting

Technology / Aviation / Altimeter Setting: A reference setting on the altimeter so that the instrument indicates an accurate altitude. MORE