Radar is a acronym for Radio Detection and Ranging
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The story of detection and ranging on metallic objects by means of reflected high-frequency radio impulses dates back to 30 April 1904,
when the German engineer Christian Hülsmeyer registered German and foreign patents
for an apparatus the called the Telemobiloscope.
German Naval Radar
In Germany, it was the Reichsmarine which showed interest in the development of this new ranging device,
which could 'see behind the clouds", although they entered the field of electromagnetic echo-ranging from
a totally different direction. As early as 1929 the Nachrichten-Versuchsabteilung (NVA: Communication trials department) at
Kiel were working on a horizontal sound-plummet capable of detecting submerged targets by measuring returning sound echoes;
this was the German forerunner of sonar.
World War Two - The Chain Home Low Radar
In the 1930s the government were growing more worried about the situation developing in Europe and decided that some form of warning system
was needed as part of the defence of this country. Fortunately, as a result of some pioneering work by Hülsmeyer (Germany), and Marconi
(Italy) the idea of using the reflection of radio waves to determine the location of distant objects was already being investigated.
Appleton had used radio echoes to determine the height of the ionosphere in 1924 and Hülsmeyer had actually proposed a system for ships
to use radio waves as a collision avoidance system. Many other scientists were carrying out similar experiments around the world so radar,
as such, had many independent births.
BIRTH OF RADAR (UK) MEMORIAL STONE
It is rare for an inventor to produce something entirely new and original on his own. It will be inspired by something that everyone earlier has failed to notice,
but more usually it results from achieving a successful application of the work of earlier pioneers.
Heinrich Hertz (1857-1894) showed that electromagnetic waves in what we term the "radio frequency" band can be reflected, refracted, and focused just like light.
In 1904 Christian Huelsmeyer successfully set up his anti-collision Telemobilskop on the Hohenzollern Bridge in Cologne to detect ships passing below.
In the 1930's the French liner Normandie was fitted with an iceberg detector in the form of a radio transmitter and receiver.
Description of various Radar types
World War Two Nomenclature Systems by Ray Mote, 6 January 1994
Development of Radar
Radar was developed (c.1935–40) independently in several countries as a military instrument for detecting aircraft and ships. One of the earliest
practical radar systems was devised (1934–35) by Sir Robert Watson-Watt, a Scots physicist. Although the technology evolved rapidly during World War II,
radar improved immensely following the war, the principal advances being higher power outputs, greater receiver sensitivity, and improved timing and
signal-processing circuits. In 1946 radar beams from the earth were reflected back from the moon. Radar contact was established with Venus in
1958 and with the sun in 1959, thereby opening a new field of astronomy - radar astronomy.
Alan Blumlein and Radar Development
EMI and Alan Blumlein were not directly responsible for the invention of Radio Direction Finding (RDF) or Radar (RAdio Detection And Ranging),
as it would eventually be known. They did however, play an increasingly important role in the development and application of certain elements that
were used in the original form of the invention, as well as the improvement and refinement of H2S, one the most widely used forms of the device.
Blumlein's association with the assembly and testing of what became the most effective of all the radar systems used during the Second World War,
would ultimately cost him his life.
THE EARLIEST RADAR DEVELOPMENT
Radar was a development rather than an invention and occurred in a number of countries around the same time. The earliest proposed application for radiolocation,
as it was called before being given the acronym of radar during the Second World War, was to prevent collisions between ships and the first apparatus was patented by
Christian Hülsmeyer in 1904. His 'telemobiloscope' was capable of detecting ships at ranges up to 3,000 metres but aroused no major interest.
Radar Technical Overview
By W.E. Knowles Middleton and Alex Mair
The General Principles of Radar
In 1888 Heinrich Hertz showed that the invisible electromagnetic waves radiated by suitable electrical circuits travel with the speed of light, and that they are
reflected in a similar way. From time to time in the succeeding decades it was suggested that these properties might be used to detect obstacles to navigation, but
the first successful experiments that made use of them were in an entirely different context, namely, to determine the height of the reflecting layers in the upper
atmosphere. One of these experiments, that of Tuve and Breit, made use of short repeated pulses of radiation, and this technique was employed in most of the developments of radar.
prepared by Emmanuel Gustin
FMG 41G (gU) Seetakt
FuMO 29 Seetakt
The original version of the Seetakt radar was developed by Gema (Gesellschaft fu"r Elektroakustische Mechanische Apparate. A Navy-sponsored firm
set up by admiral Mertens, by coincidence a WWI U-boat commander.) in 1935 as one of the first operational German radars. It operated on 82cm,
and its antenna was an array of horizontal or vertical dipoles. Versions of Seetakt were used on land or carried by surface ships, such as the 'Graf Spee' and 'Bismarck'.
U-boat Radar Detectors
prepared by Emmanuel Gustin
FuMB 1 Metox 600A
Installed in U-boats from August 1942 onwards, this was a receiver, tuned to pick up 1.5 meter ASV radar at a safe distance. It was named after its (French!) manufacturer. A Wellington equipped with
ASV Mk.I fell into German hands in the summer of 1941, in North Africa, and this revealed the secrets of the radar.
Timeline 1895 X-rays discovered by Wilhelm Roentgen. 1900 Intensifying screens developed by Thomas Edison. 1901 German physicist Christian Helsmeyer discovers that radio echoes can prevent collisions.
1913 "Hot cathode" X-ray tube, W. D. Coolidge. 1915 French professor P. Langevin develops sonar. 1927 Radioactive tracers, de Hevesy. 1930 Rotating anode X-ray tube. 1937 Electron microscope. 1939 Henry Boot
and John Randall develop resonant-cavity magnetron. 1940 Radar development begins. 1942 Demonstration of the detection of ships from the air.
The Development of Radar
During World War I, the German zeppelin and Gotha biplane bombing raids on Britain were usually spotted by observers on the ground and fighter patrols in the air. But in the period between world wars,
a specialized type of aircraft known as the bomber was evolving in Europe. As the speed and bomb load of the bomber increased, British politicians of the 1930s became increasingly worried. With Britain being
so close to countries on the Continent, they envisioned a scenario where fast bombers would fly the short distance to one of Britain's major cities, and attack without being detected. With a shortage of planes
and pilots, keeping round-the-clock fighter patrols airborne was next to impossible. Something else had to be done.
In the period before World War II, all the major powers were developing radio location systems. The British concentrated on aircraft detection and location while the Germans developed aircraft
navigation systems. These devices operated at meter wave lengths.
British researchers also developed the most useful version of a vacuum tube called the cavity magnetron. This tube generated hundreds of watts of power at microwave frequencies, enough to produce
echoes from objects many miles away. Britain lacked the large-scale manufacturing facilities to mass-produce the magnetron, so one was shipped in secrecy across the Atlantic in 1940 to the U. S.,
where researchers at the MIT Radiation Laboratory and elsewhere developed many production versions for a wide variety of radar sets used in the war.
Some pics and data about German WW II radar systems
Radar and the Observation of UFOs by Roy H. Blackmer, Jr.
Although stressing the detectability of UFOs by radar, this article give a good background knowledge about how radar systems are operating.