How Does Radar Work?

RADAR (Radio Detection And Ranging) works by emitting short pulses of radio waves from a transmitter/antenna. When these waves encounter an object (aircraft, ship, rain cloud), some energy is reflected back. A receiver (often the same antenna) detects this echo. By measuring the time between transmission and reception, and knowing radio waves travel at the speed of light (about 300,000 km/s), the system calculates the distance to the object. The antenna direction reveals the object bearing, and the Doppler shift of the returned frequency indicates whether the object is moving toward or away, and how fast. Radar was developed independently by several nations in the 1930s-40s and was crucial in the Battle of Britain.