The Valour and the Horror

Radar: (Radio detection and ranging) locates an object by bombarding it with radio waves and measuring the time taken for the waves to go out and bounce back to the transmitter. As radio waves travel at a constant speed of 186,000 mps, a targets position can fixed. Radar was used by both sides during the war.

Radar was tested for the first time in action during the Battle of Britain. A chain of costal radar stations provided early warning of German planes crossing the Channel and North Sea and gave the RCAF vital time to send up fighters to intercept the German bombers.

Radar worked by the the antenna (A) above, sending out radio waves in short pulses. When a plane flew into the beam it reflected some of the waves back to the antenna. The transmitter/receiver ,( left), amplified the signal and displayed it on a cathode ray tube. There it was shows as a blip of light on the screen marked off in miles. The blip, (left) shows the target is ten miles away.

Radar also allowed the operator to estimate the number of targets and gave their bearing and height.