H2S was the first airborne, ground scanning radar system. It was developed in Britain during World War II for the Royal Air Force, and was used in various RAF bomber aircraft from 1943 through to the 1990s. It was designed to identify targets on the ground for night and all-weather bombing. The early variants of the transmitter/receiver equipment were officially known as TR3159 (H2S Mk I/ASV VIB) or TR3191 (H2S Mk II).
On January 30, 1943, H2S radar was used by RAF bombers for navigation for the first time, and so became the first ground mapping radar to be used in combat. Initially it was fitted to Stirling and Halifax bombers and provided ground mapping for navigation and night bombing.
This development using ten-centimeter radar, (actually 9.1 cm) was possible thanks to the development of the cavity magnetron. Later versions of H2S reduced the wavelength, first to 3 cm and then 1.5 cm at which wavelength the system was capable of detecting rain clouds.
On a raid to Cologne on 2/3 February 1943, a Stirling Pathfinder was shot down over the Netherlands. The H2S set it was carrying was damaged but not beyond repair (fortunately for the Germans it was only the second operational use of H2S), and, known as the Rotterdam Gerät, Telefunken was able to reassemble it, with the exception of the PPI display that had been destroyed. Eventually this led to the development of the Funkgerät (FuG) 350 Naxos radar detector, which enabled Luftwaffe night fighters to home on the transmissions of H2S.
The United States later adapted the X-Band version of H2S (H2S Mk III) as the H2X radar which they regarded as a significant improvement. H2X was tested by RAF Bomber Command in 1945.
Famous quotes containing the word radar:
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—Melinda M. Marshall (20th century)