Pulse Doppler Radar Development, 1940–1945

Pulse Doppler radar techniques are widely used in modern radars to distinguish moving targets from clutter, often with complex adaptive signal processing. Research into the exploitation of the Doppler shift from moving targets started very soon after the first radars entered service, in about 1940. Over the course of the next five years, pulse Doppler techniques evolved from simple A-scope displays of fluctuating signals through to the first MTI systems, using delay line cancellers. This article reviews the evolution of pulse Doppler techniques from 1940 to 1945, outlining the research and development undertaken in France, Britain, USA, and Germany.