Science glossary film: Altitude

Height above sea level or other reference point on the Earth's surface. Altitude is usually measured with GPS equipment, which can give a very accurate position in three dimensions, or with pressure-based altimeters that can use the steady drop in air pressure as altitude increases.

Altitude is usually measured with GPS equipment, which can give a very accurate position in three dimensions, or with pressure-based altimeters that can use the steady drop in air pressure as altitude increases.