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How does radar work?

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Quick answer

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.

Step by step

  1. A transmitter sends out pulses of radio waves.
  2. The waves reflect off objects like aircraft or rain.
  3. The time for the echo to return gives the object's distance.
  4. A frequency shift in the echo (Doppler) reveals its speed.
  5. It works day or night and through clouds, unlike the eye.

People also ask

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.