An "absolute altimeter" is also commonly known as a "radar altimeter" as it measures an aircraft's altitude relative to the ground by emitting and receiving radio waves. Another synonym for an absolute altimeter is a "height finder," which is used by the military to determine enemy aircraft altitude. An "electronic altimeter," also known as a "radio altimeter," is commonly used in helicopters and other aircraft. A "laser altimeter" is a type of altimeter that uses lasers to measure the distance between the ground and an object. Lastly, a "barometric altimeter" is a device that measures altitude based on changes in atmospheric pressure. These synonyms for "absolute altimeter" are often used interchangeably in aviation and other industries.