Definition
The radio energy reflected back to a radar antenna by an object such as an aircraft, terrain feature, or area of precipitation, producing a detectable return that is displayed on the radar screen.
Plain English
A radar sends out a radio pulse. When that pulse hits something solid or dense enough, part of it bounces back. That bounce-back is the radar echo, and it is what shows up as a target on the screen.
Context Anchor
Seen in radar navigation, ATC radar discussions, and weather radar descriptions when something is detected by radar.
Derivation
Echo comes from the Greek 'ēchō,' meaning a returning sound. Radar borrows the word because the principle is the same: a signal goes out, hits something, and comes back. The sound-to-radio shift is just a change in the type of wave.
Why Pilots Care
It is how radar systems detect and display the location and movement of aircraft.
Grounding Statement
A radar site sends out energy, and a radar echo is the part that comes back after hitting something.
Intuition Check
A radar echo is not a sound echo. It is reflected radio energy received by a radar system.
Example Sentence 1
The controller identified the aircraft by its radar echo on the approach scope.
Example Sentence 2
The pilot requested vectors after losing the radar echo due to terrain masking.