Birth of radar memorial. On 26th February 1935 in the field opposite Robert Watson-Watt and Arnold Wilkins showed for the first time in Britain that aircraft could be detected by bouncing radio waves off them. By 1939 there were 20 stations tracking aircraft at distances up to more than 100 miles. Later known as radar, it was this invention. more than any other, that saved the RAF from defeat in the 1940 Battle Of Britain.