Technology
How does radar work?
Radar works by sending out radio waves and listening for the echoes that bounce off objects. By timing how long the echo takes to return it calculates distance, and shifts in the echo reveal speed — letting it 'see' planes, storms, and ships.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how radar works.
Step by step
- 1A transmitter sends out pulses of radio waves.
- 2The waves reflect off objects like aircraft or rain.
- 3The time for the echo to return gives the object's distance.
- 4A frequency shift in the echo (Doppler) reveals its speed.
- 5It works day or night and through clouds, unlike the eye.
Frequently asked questions
- How does radar measure distance?
- Radio waves travel at a known speed, so the time an echo takes to return directly gives how far away the object is.
- How does radar measure speed?
- Movement shifts the echo's frequency (the Doppler effect); the size of the shift reveals how fast the object is approaching or receding.
- What does radar stand for?
- RAdio Detection And Ranging — detecting objects and measuring their range using radio waves.