Watson-Watt, Robert Alexander (1892–1973)

Scottish physicist who developed a forerunner of radar and was in charge of the radar development programme in the UK from the 1930s onwards. In 1935 he proposed a method of radiolocation of aircraft – a key factor in the Allied victory over German aircraft in World War II. He was knighted in 1942.

Watson-Watt was born in Brechin, Angus, and educated at the University of St Andrews. He spent a long career in government service (1915–52).

Watson-Watt patented in 1919 a device concerned with radiolocation by means of short-wave radio waves. By 1935 he had made it possible to follow an aeroplane by the radio-wave reflections it sent back. By 1938, radar stations were in operation, and during the Battle of Britain in 1940 radar made it possible for the British to detect incoming German aircraft as easily by night as by day, and in all weathers including fog. Early in 1943 microwave aircraft-interceptor radars were operational, ending night-bombing raids on Britain.

The first radar sets specifically designed for airborne surface-vessel detection were flown in 1943. Before the USA joined the war, Watson-Watt went there to advise on the setting-up of radar systems.