Differences

This shows you the differences between two versions of the page.

--- radar:history [2018/06/10 21:22] – galkina
+++ radar:history [2026/04/28 15:13] (current) – external edit 127.0.0.1
@@ Line 3: / Line 3: @@
 During the 1930s, efforts to use radio echoes for aircraft detection were initiated independently and almost simultaneously in eight countries that were concerned with the prevailing military situation and that already had practical experience with radio technology. The United States, Great Britain, Germany, France, the Soviet Union, Italy, the Netherlands, and Japan all began experimenting with radar within about two years of one another and embarked, with varying degrees of motivation and success, on its development for military purposes. Several of these countries had some form of operational radar equipment in military service at the start of World War II.
@@ Line 183: / Line 184: @@
   - Наземные американские и английские радиолокационные станции. — Москва: Военное издательство министерства вооружённых сил союза ССР, 1947.
   - http://wiki.wargaming.net/ru/Navy:Радары_США
+=== German Radars development history ===
+==Summary==
+Germany is a pioneer of using electromagnetic waves to detect objects. In 1888, Henry Hertz, who first proved the existence of electromagnetic waves, discovered that these waves, like light, can be reflected from metal surfaces.
+The radio engineering device for detecting ships was created in Germany by Christian Hulsmeyer in 1904. Often referred to as the first radar system, this did not directly measure the range (distance) to the target, and thus did not meet the criteria to be given this name.
+Over the following three decades in Germany, a number of radio-based detection systems were developed but none were true radars. This situation changed before World War II. Developments in three leading industries are described
+----
+==GEMA==
+In the early 1930s, physicist Rudolf Kühnhold, Scientific Director at the Kriegsmarine (German navy) Nachrichtenmittel-Versuchsanstalt (NVA—Experimental Institute of Communication Systems) in Kiel, was attempting to improve the acoustical methods of underwater detection of ships. He concluded that the desired accuracy in measuring distance to targets could be attained only by using pulsed electromagnetic waves.
+During 1933, Kühnhold first attempted to test this concept with a transmitting and receiving set that operated in the microwave region at 13.5 cm (2.22 GHz). The transmitter used a Barkhausen-Kurz tube (the first microwave generator) that produced only 0.1 watt. Unsuccessful with this, he asked for assistance from Paul-Günther Erbslöh and Hans-Karl Freiherr von Willisen, amateur radio operators who were developing a VHF system for communications. They enthusiastically agreed, and in January 1934, formed a company, Gesellschaft für Elektroakustische und Mechanische Apparate (GEMA), for the effort. From the start, the firm was always called simply GEMA.
+Work on a Funkmessgerät für Untersuchung (radio measuring device for research) began in earnest at GEMA. Hans Hollmann and Theodor Schultes, both affiliated with the prestigious Heinrich Hertz Institute in Berlin, were added as consultants. The first apparatus used a split-anode magnetron purchased from Philips in the Netherlands. This provided about 70 W at 50 cm (600 MHz), but suffered from frequency instability. Hollmann built a regenerative receiver and Schultes developed Yagi antennas for transmitting and receiving. In June 1934, large vessels passing through the Kiel Harbor were detected by Doppler-beat interference at a distance of about 2 km (1.2 mi). In October, strong reflections were observed from an aircraft that happened to fly through the beam; this opened consideration of targets other than ships.
+Kühnhold then shifted the GEMA work to a pulse-modulated system. A new 50 cm (600 MHz) Philips magnetron with better frequency stability was used. It was modulated with 2- μs pulses at a PRF of 2000 Hz. The transmitting antenna was an array of 10 pairs of dipoles with a reflecting mesh. The wide-band regenerative receiver used Acorn tubes from RCA, and the receiving antenna had three pairs of dipoles and incorporated lobe switching. A blocking device (a duplexer), shut the receiver input when the transmitter pulsed. A Braun tube (a CRT) was used for displaying the range.
+The equipment was first tested at a NVA site at the Lübecker Bay near Pelzerhaken. During May 1935, it detected returns from woods across the bay at a range of 15 km (9.3 mi). It had limited success, however, in detecting a research ship, Welle, only a short distance away. The receiver was then rebuilt, becoming a super-regenerative set with two intermediate-frequency stages. With this improved receiver, the system readily tracked vessels at up to 8 km (5.0 mi) range.
+In September 1935, a demonstration was given to the Commander-in-Chief of the Kriegsmarine. The system performance was excellent; the range was read off the Braun tube with a tolerance of 50 meters (less than 1 percent variance), and the lobe switching allowed a directional accuracy of 0.1 degree. Historically, this marked the first naval vessel equipped with radar. Although this apparatus was not put into production, GEMA was funded to develop similar systems operating around 50 cm (500 MHz). These became the Seetakt for the Kriegsmarine and the [[https://en.wikipedia.org/wiki/Freya_radar|Freya]] for the Luftwaffe (German Air Force).
+{{https://upload.wikimedia.org/wikipedia/commons/d/d0/Auderville_Freyas.jpg?200}}
+Low-level aerial reconnaissance photograph of the Freya radar installations at Auderville, France
+{{https://upload.wikimedia.org/wikipedia/commons/8/8d/Bundesarchiv_Bild_141-2732%2C_Radarger%C3%A4te_%22W%C3%BCrzburg-Riese%22_und_%22Freya%22.jpg?200}}
+ Würzburg-Riese and Freya
+Kühnhold remained with the NVA, but also consulted with GEMA. He is considered by many in Germany as the Father of Radar. During 1933–6, Hollmann wrote the first comprehensive treatise on microwaves, Physik und Technik der ultrakurzen Wellen (Physics and Technique of Ultrashort Waves), Springer 1938
+----
+==Telefunken==
+In 1933, when Kühnhold at the NVA was first experimenting with microwaves, he had sought information from Telefunken on microwave tubes. (Telefunken was the largest supplier of radio products in Germany) There, Wilhelm Tolmé Runge had told him that no vacuum tubes were available for these frequencies. In fact, Runge was already experimenting with high-frequency transmitters and had Telefunken’s tube department working on cm-wavelength devices.
+In the summer of 1935, Runge, now Director of Telefunken’s Radio Research Laboratory, initiated an internally funded project in radio-based detection. Using Barkhausen-Kurz tubes, a 50 cm (600 MHz) receiver and 0.5-W transmitter were built. With the antennas placed flat on the ground some distance apart, Runge arranged for an aircraft to fly overhead and found that the receiver gave a strong Doppler-beat interference signal.
+Runge, now with Hans Hollmann as a consultant, continued in developing a 1.8 m (170 MHz) system using pulse-modulation. Wilhelm Stepp developed a transmit-receive device (a duplexer) for allowing a common antenna. Stepp also code-named the system Darmstadt after his home town, starting the practice in Telefunken of giving the systems names of cities. The system, with only a few watts transmitter power, was first tested in February 1936, detecting an aircraft at about 5 km (3.1 mi) distance. This led the Luftwaffe to fund the development of a 50 cm (600 MHz) gun-laying system, the [[https://en.wikipedia.org/wiki/W%C3%BCrzburg_radar|Würzburg]].
+{{https://upload.wikimedia.org/wikipedia/commons/3/3b/Bundesarchiv_Bild_101I-662-6660-27A%2C_Frankreich%2C_Radarger%C3%A4t_%22W%C3%BCrzburg%22.jpg?200}}
+Würzburg D in use. The quirl conical scanning antenna is prominent.
+==Lorenz==
+Since before the First World War, Standard Elektrik Lorenz had been the main supplier of communication equipment for the German military and was the main rival of Telefunken. In late 1935, when Lorenz found that Runge at Telefunken was doing research in radio-based detection equipment, they started a similar activity under Gottfried Müller. A pulse-modulated set called Einheit für Abfragung (DFA – Device for Detection) was built. It used a type DS-310 tube (similar to the Acorn) operating at 70 cm (430 MHz) and about 1 kW power, it had identical transmitting and receiving antennas made with rows of half-wavelength dipoles backed by a reflecting screen.
+In early 1936, initial experiments gave reflections from large buildings at up to about 7 km (4.3 mi). The power was doubled by using two tubes, and in mid-1936, the equipment was set up on cliffs near Kiel, and good detections of ships at 7 km (4.3 mi) and aircraft at 4 km (2.5 mi) were attained.
+The success of this experimental set was reported to the Kriegsmarine, but they showed no interest; they were already fully engaged with GEMA for similar equipment. Also, because of extensive agreements between Lorenz and many foreign countries, the naval authorities had reservations concerning the company handling classified work. The DFA was then demonstrated to the Heer (German Army), and they contracted with Lorenz for developing Kurfürst (Elector), a system for supporting Flugzeugabwehrkanone (Flak, anti-aircraft guns).
+==Bibliography==
+  -https://en.wikipedia.org/wiki/History_of_radar
+----
+===UK Radar development history ===
+[[https://en.wikipedia.org/wiki/Robert_Watson-Watt||Robert Watson Watt]], an employee of the Meteorological Service, for a long time worked on the development of a radio instrument that captures the parameters of atmospheric electrical discharges. The need to identify the direction of the source of short-time signals led him in 1927 to create a system of directed rotating antennas, the signal from which was fed to the oscilloscope. In fact, this device was__ the prototype of the radio direction finder__.
+In 1934, the UK created the Committee for Scientific Survey of Air Defense (CSSAD), of which Watson-Watt was one of the employees.
+The course of further research was largely predetermined by the article of one of the tabloid newspapers about the huge radio emitters [[https://en.wikipedia.org/wiki/Death_ray|"death rays"]] allegedly developed in Germany. Members of the committee reacted to this news with a certain amount of skepticism, but nevertheless decided to contact one of the experts in the field of radio engineering, Arnold Wilkins, to receive substantiated comments on the mysterious rays.
+In January 1935, theoretical calculations were carried out which led to the conclusion that the statements about the "rays of death" were fantastic, but the calculations themselves showed that in the case of the reflection of radio waves from various objects that are at a considerable distance, the reflected signal will have a sufficient level for its reception and display on the oscilloscope screen. Within a few weeks Wilkins prepared a report in which he outlined the general idea of receiving reflected radio waves.
+He also gave detailed calculations of the required transmitter power, the signal reflection characteristics of the aircraft and the sensitivity parameters of the receiver. Wilkins suggested using a directional receiver based on the idea of detecting lightning by Watson-Watt. The delay time of the reflected signal made it possible to measure the distance to the aircraft that reflected the signal. On February 12, 1935, Watson-Watt sent this information to the Ministry of Aviation in a secret report entitled "Detection of aircraft by radio communication methods".
+The Ministry of Aviation was skeptical of the idea of Wilkins, since the reflection of radio signals at that time was not confirmed by practical experiments. To prove his idea, Wilkins conducted a scientific experiment. On February 26, 1935, the Handley Page Heyford bomber flew between the receiving station in Northamptonshire and the BBC broadcasting station in Daventry. The signal reflected by the aircraft was received by Wilkins' receiver.
+The proof of reflection of the signal was the occurrence of a Doppler frequency shift , which occurs when the radio waves are reflected from moving objects. Thus, the experiment allowed not only to determine that the aircraft is at a distance of 13 km from the receiver, but also to calculate its speed. This convincing test, known as the Deventry experiment, was presented to the Ministry of Aviation and it decided to build a full-fledged demonstration system.
+The construction was carried out at the military range Orford Ness in Suffole on the coast of the North Sea. In mid-May 1935, six transmitting and four receiving towers were built. In June, general testing began. On June 17, the Supermarine Scapa flying boat was discovered at a distance of 27 km. Thus, this day can be considered __the day of origin of the British radar__. Watson-Watt, Wilkins and transmitter designer Edward Bowen proposed to name their radar installation - from RAdio Detection And Ranging (RADAR) - radio detection and range detection.
+In December 1935, the British Minister of Finance allocated 60,000 pounds sterling to build a system of five stations called [[https://en.wikipedia.org/wiki/Chain_Home|Chain Home (CH)]], covering approaches to the Thames estuary.
+{{https://upload.wikimedia.org/wikipedia/commons/d/de/Chain_home_coverage.jpg?200}}
+Chain home coverage
+At the end of 1935, Bowen suggested using a bistatic radar, the transmitters of which would be installed on the ground, and the receivers would be placed on airplanes. Thus, the beginning of the development of radars for the interception of air targets (AI) was started, and later, when the possibility of detecting ships - ASVs was discovered by chance.
+In 1940, [[https://en.wikipedia.org/wiki/John_Randall_(physicist)|John Randall]] and Harry Booth finalized the electron tube - a magnetron, which allowed using a 10-cm range of waves in radars. This compact device made it possible to make a real breakthrough in radar, as it was able to generate radio pulses in the range of 10 cm, which required compact radar antennas freely placed on airplanes, and the waves themselves made it possible to detect submarines moving at periscope depth.
+----
+==Bibliography==
+  -https://en.wikipedia.org/wiki/History_of_radar
@@ Line 528: / Line 617: @@
 ==Bibliography==
   -Bibliography and links
   -http://home.e01.itscom.net/ikasas/radar/jprdf06.htm
@@ Line 537: / Line 625: @@
+----
+===Netherlands===
+Early radio-based detection in the Netherlands was along two independent lines: one a microwave system at the firm Philips and the other a VHF system at a laboratory of the Armed Forces.[52]
+The Philips Company in Eindhoven, Netherlands, operated Natuurkundig Laboratorium (NatLab) for fundamental research related to its products. NatLab researcher Klaas Posthumus developed a magnetron split into four elements.[53] In developing a communication system using this magnetron, C.H.J.A. Staal was testing the transmission by using parabolic transmitting and receiving antennas set side-by-side, both aimed at a large plate some distance away. To overcome frequency instability of the magnetron, pulse modulation was used. It was found that the plate reflected a strong signal.
+Recognizing the potential importance of this as a detection device, NatLab arranged a demonstration for the Koninklijke Marine (Royal Netherlands Navy). This was conducted in 1937 across the entrance to the main naval port at Marsdiep. Reflections from sea waves obscured the return from the target ship, but the Navy was sufficiently impressed to initiate sponsorship of the research. In 1939, an improved set was demonstrated at Wijk aan Zee, detecting a vessel at a distance of 3.2 km (2.0 mi).
+A prototype system was built by Philips, and plans were started by the firm Nederlandse Seintoestellen Fabriek (a Philips subsidiary) for building a chain of warning stations to protect the primary ports. Some field testing of the prototype was conducted, but the project was discontinued when Germany invaded the Netherlands on May 10, 1940.
+==Bibliography==
+  -https://en.wikipedia.org/wiki/History_of_radar
+----
+===France===
+In 1927, French physicists [[https://en.wikipedia.org/wiki/Camille_Gutton|Camille Gutton]] and Emile Pierret experimented with magnetrons and other devices generating wavelengths going down to 16 cm. Camille's son, Henri Gutton, was with the Compagnie générale de la télégraphie sans fil (CSF) where he and Robert Warneck improved his father's magnetrons.
+In 1934, following systematic studies on the magnetron, the research branch of the CSF, headed by Maurice Ponte, submitted a patent application for a device designed to detect obstacles using continuous radiation of ultra-short wavelengths produced by a magnetron.[57] These were still CW systems and depended on Doppler interference for detection. However, as most modern radars, antennas were collocated. The device was measuring distance and azimuth but not directly as in the later "radar" on a screen (1939). Still, this was the first patent of an operational radio-detection apparatus using centimetric wavelengths.
+The system was tested in late 1934 aboard the cargo ship Oregon, with two transmitters working at 80 cm and 16 cm wavelengths. Coastlines and boats were detected from a range of 10–12 nautical miles. The shortest wavelength was chosen for the final design, which equipped the liner SS Normandie as early as mid-1935 for operational use.
+In late 1937, Maurice Elie at SFR developed a means of pulse-modulating transmitter tubes. This led to a new 16-cm system with a peak power near 500 W and a pulse width of 6 μs. French and U.S. patents were filed in December 1939. The system was planned to be sea-tested aboard the Normandie, but this was cancelled at the outbreak of war.
+At the same time, Pierre David at the Laboratoire National de Radioélectricité (National Laboratory of Radioelectricity, LNR) experimented with reflected radio signals at about a meter wavelength. Starting in 1931, he observed that aircraft caused interference to the signals. The LNR then initiated research on a detection technique called barrage électromagnétique (electromagnetic curtain). While this could indicate the general location of penetration, precise determination of direction and speed was not possible.
+In 1936, the Défense Aérienne du Territoire (Defence of Air Territory), ran tests on David’s electromagnetic curtain. In the tests, the system detected most of the entering aircraft, but too many were missed. As the war grew closer, the need for an aircraft detection was critical. David realized the advantages of a pulsed system, and in October 1938 he designed a 50 MHz, pulse-modulated system with a peak-pulse power of 12 kW. This was built by the firm SADIR.
+France declared war on Germany on September 1, 1939, and there was a great need for an early-warning detection system. The SADIR system was taken to near Toulon, and detected and measured the range of invading aircraft as far as 55 km (34 mi). The SFR pulsed system was set up near Paris where it detected aircraft at ranges up to 130 km (81 mi). However, the German advance was overwhelming and emergency measures had to be taken; it was too late for France to develop radars alone and it was decided that her breakthroughs would be shared with her allies.
+==Bibliography==
+  -https://en.wikipedia.org/wiki/History_of_radar