In February 1935, following a query about the possibility of producing a death ray, Robert Watson-Watt submitted a memorandum on ‘Detection of Aircraft by Radio Methods’. In it, he foresaw what were to become the ‘Three Steps to Victory’ in a possible future conflagration - Radar (or RAdio Direction And Ranging), the cathode ray oscilloscope indicator and operational research. Following successful trials, he was appointed Superintendent of the Air Ministry’s Research Station at Bawdsley.
The outcome of this appointment was Watson-Watt's proposal that a chain of radio direction finding (RDF) or 'Chain Home' (CH) stations be built around the British coast. By the time war was declared, there were 18 operational Chain Home stations round the south and east coast of England, capable of detecting enemy aircraft 100 miles away. By 1944, there were 208 stations ringing the entire UK coast, forming a highly efficient early warning system. The Chain Home system successfully detected the approach of enemy aircraft, enabling the Royal Air Force to deploy its resources effectively, which resulted in victory in the Battle of Britain.
Fighter Aircraft Radar - A Scottish Success Story
The English Electric Lightning, a supersonic fighter aircraft developed in the early 1950s, required high-quality Radar to fulfil its role as an interceptor. The Radar work was contracted to Ferranti Ltd in Edinburgh, to a plant that had been established during the war to manufacture gyro-stabilised gun-sights and therefore knew something about fire-control. The Ferranti engineers used a great deal of innovation to produce the Airpass family of fire-control radars, achieving a new level of sophistication at a low weight level.
The Lightning radar, designated A.I. 23, performed fire-control computation for the Red-Top infra-red missile and for air-to-air gunnery. Detection range was typically 40 miles against the Russian 'Bear' bomber which was a primary target over the North Sea during many cold-war interceptions. The radar would guide the Interceptor to close range, often at night, where a floodlit tail photograph could be taken and a token diplomatic protest lodged. Later developments of the Airpass series Radars included ground-mapping and air-to-surface depressed-sightline weapon delivery.
Ferranti went on to develop terrain-following radar (TFR) technology for the British TSR-2 tactical strike and reconaissance aircraft. Although the TSR-2 project was cancelled in 1965, TFR technology continued to develop. TFR allowed a very low-flying aircraft to maintain a relatively constant altitude above ground level automatically. This was significant due to the development of effective surface-to-air missiles, which an enemy could launch as soon as an incoming air attack was detected by ground-based radar.TFR technology thus allowed attacking aircraft to fly at very low altitude, where it was harder for ground-based radar to dectect them. The next generation of fighter aircraft, including the General Dynamics F-111, Blackburn Buccaneer, McDonnell F4 Phantom and Panavia Tornado, all made use of this technology.