What is a radio altimeter used for?

Definition. A radio altimeter is an airborne electronic device capable of measuring the height of the aircraft above terrain immediately below the aircraft.

What does altimeter indicate?

The altimeter measures the height of an aircraft above a fixed level. The instrument senses this by taking the ambient air pressure from the static port. That air is plumbed through the back of the panel and into the back case of the altimeter. Inside the altimeter is a sealed disc called an aneroid, or bellows.

Does radio altimeter work over water?

Yes. Radio waves reflect particularly well off seawater. The best modern radar altimeters employ computers that can read and compute the difference between outgoing and incoming ( reflected) signals fast enough to compensate for the fact that ocean and lake water usually has ever-changing wave heights.

Why is it important to have the correct altimeter setting?

You need the correct setting before you land. In this case, the altimeter setting amounts to what a barometer at that location would read at sea level at that time. As the air pressure changes the observer would adjust the altimeter to station elevation and read the setting from the Kollsman window.

Why is the radio altimeter placed in the tail of aircraft?

Why is the radio altimeter placed in the tail of aircraft? Radio altimeter measures precise distance from the ground and since the tail is closer to the ground than the nose, to measure the minimum distance it is placed in the tail.

Is radar altimeter same as radio altimeter?

A radar altimeter (RA), radio altimeter (RALT), electronic altimeter, or reflection altimeter measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground, reflect, and return to the craft.

How does watch altimeter work?

The altimeter works on the relation between the atmospheric pressure and altimeter. The atmospheric pressure decreases as the altitude increases. Basically, the altimeter watch converts biometric pressure into altitude. The barometer is built inside the watch itself.