Radar - or radio detecting and ranging - was one of the most important factors in the success of Britain’s air defences during the Battle of Britain.

Radar could be used to detect and locate incoming enemy aircraft. It worked by sending out radio waves which would bounce off solid objects at a distance, enabling operators to estimate four important things about approaching raids: the range (distance), bearing (direction), strength and height.

Radar was a crucial part of the Dowding System, Britain's highly effective and sophisticated air defence network. This system allowed Royal Air Force (RAF) Fighter Command to respond to incoming German attacks and use its precious resources of pilots and aircraft to the best possible effect.

Radar gave early warning of approaching raids. This information filtered through Fighter Command HQ and was then communicated throughout the defence network. This gave fighter defences vital time to prepare for and intercept the attacks.

Radar wasn't always accurate and didn't produce a complete picture of the incoming threat - additional intelligence was provided by the Observer Corps. Its effectiveness also depended on the skills and judgment of the operators employed to interpret the signals.  


A CH (Chain Home) Radar Station on the East Coast

A CH (Chain Home) Radar Station on the East Coast, 1946, William Thomas Rawlinson.

CH Stations were radar stations covering the east and south coasts of Britain. By 1940 the chain was completed with the addition of Chain Home Low (CHL) stations, which could detect low-flying aircraft.

Britain wasn’t alone in its use of radar; it had actually been invented in Germany. What really gave Britain the edge was that Germany failed to recognise how vital radar was to the country’s defence. Although they did attack some stations, only Ventnor on the Isle of Wight was put out of action for any significant period. The Germans never concentrated their efforts on destroying radar stations and so this crucial element of Britain’s air defence remained generally intact throughout the Battle of Britain.

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