What is the history of the Doppler RADAR?

Doppler RADAR measures the speed of objects using the Doppler effect (discovered by the Austrian mathematician and physicist Christian Andreas Doppler in 1842 at the Prague Polytechnic) in addition to the position measured by ordinary RADAR.

The earliest version of Doppler RADAR was introduced by the U.S. Navy during WW2 on night fighters.

Doppler RADARs are used now in aviation, sounding satellites, meteorology, police speed guns, radiology and healthcare (fall detection and risk assessment, nursing or clinic purpose), and bistatic radar (surface-to-air missile).