radar altimeter

A radar altimeter is an instrument used on aircraft to measure the distance between the plane and the ground directly beneath it. It works by emitting radio waves downward, which reflect off the terrain and return to the device. By calculating the time it takes for the signals to come back, the altimeter precisely determines the aircraft's altitude above the ground, especially at low altitudes or during landing. This information helps pilots maintain safe heights, avoid obstacles, and ensure smooth flight operations, especially in conditions of low visibility or complex terrain.