SAMPSON is derived from the Multi-function Electronically Scanned Adaptive Radar (MESAR) programme. MESAR 1 development commenced in 1982 as a partnership between Plessey, Roke Manor Research and the Defence Evaluation and Research Agency. Plessey was acquired by Siemens in 1989 to become Siemens-Plessey, itself acquired by British Aerospace in 1998. British Aerospace became BAE Systems in November 1999. MESAR 1 trials occurred between 1989 and 1994. MESAR 2 development began in August 1995, of which SAMPSON is a derivative. The Royal Navy intended to deploy the SAMPSON MFR on its version of the Horizon CNGF - a collaboration with France and Italy to produce anti-air warfare frigates.
History
SAMPSON
SAMPSON | History
It was developed in a partnership between Plessey, Roke Manor Research and the Defence Evaluation and Research Agency BAE Systems Maritime BAE Systems Maritime. The S1850M is produced by BAE Systems Integrated System Technologies (formerly AMS UK) and Thales.
what was one of the provisions of the petition of right (1628)
user
No person should be forced to provide a gift, loan or tax without an Act of Parliament.
assistant
what does the term "petition of right" refer to?
user
It is an English constitutional document setting out specific individual protections against the state.
assistant
who formulated it?
user
Charles I
assistant
what kinds of provisions does it have?
user
No person should be forced to provide a gift, loan or tax without an Act of Parliament. No free individual should be imprisoned or detained unless a cause has been shown. Soldiers or members of the Royal Navy should not be billeted in private houses without the free consent of the owner.
assistant
which period marked the age of sail for the navy mentioned above?
user
During the reign of Henry VIII.
assistant
do they have an escort fleet?
user
Yes, there are six Type 45 destroyers and 13 Type 23 frigates in active service.
assistant
what is type 45?
user
It is also known as the D or "Daring" class. It is a class of six guided missile destroyers built for the United Kingdom's Royal Navy.
assistant
did its engine face any trouble?
user
On occasion there have been near-complete power generation failures, temporarily disabling propulsion, power generation for weapons, navigational systems and other purposes, leaving the ships vulnerable to "total electric failure".
assistant
how strong was their air defense?
user
The Royal Navy describes the destroyers' mission as being "to shield the Fleet from air attack". It is equipped with the Sea Viper air-defence system utilizing the SAMPSON active electronically scanned array multi-function radar and the S1850M long-range radar. PAAMS is able to track over 2,000 targets and simultaneously control and coordinate multiple missiles in the air at once, allowing a large number of tracks to be intercepted and destroyed at any given time.
assistant
how does the first mentioned radar function?
user
The SAMPSON multi function radar can detect all types of targets out to a distance of 400 km, and is capable of tracking hundreds of targets at any one time.
assistant
who developed it?
user
Robert Morris Page was assigned by Taylor to implement Young's suggestion. Page designed a transmitter operating at 60 MHz and pulsed 10 μs in duration and 90 μs between pulses. In December 1934, the apparatus was used to detect a plane at a distance of one mile (1.6 km) flying up and down the Potomac. Although the detection range was small and the indications on the oscilloscope monitor were almost indistinct, it demonstrated the basic concept of a pulsed radar system. Based on this, Page, Taylor, and Young are usually credited with building and demonstrating the world's first true radar.
History of radar | United States Navy
The SAMPSON is a multi-function dual-face active electronically scanned array radar produced by BAE Systems Maritime. It is made out of high-carbon steel and is covered with an anti-radar paint. It is the fire control radar component of the Sea Viper naval air defence system. It was previously designated PAAMS(S) to distinguish it from the PAAMS system on the Franco-Italian Horizon Class. The SAMPSON multi function radar can detect all types of targets out to a distance of 400 km, and is capable of tracking hundreds of targets at any one time. Sea Viper uses this information to assess and command target priorities, and calculate the optimum launch time for its Aster missiles.
SAMPSON | Introduction
SAMPSON is derived from the Multi-function Electronically Scanned Adaptive Radar (MESAR) programme. MESAR 1 development commenced in 1982 as a partnership between Plessey, Roke Manor Research and the Defence Evaluation and Research Agency. Plessey was acquired by Siemens in 1989 to become Siemens-Plessey, itself acquired by British Aerospace in 1998. British Aerospace became BAE Systems in November 1999. MESAR 1 trials occurred between 1989 and 1994. MESAR 2 development began in August 1995, of which SAMPSON is a derivative. The Royal Navy intended to deploy the SAMPSON MFR on its version of the Horizon CNGF - a collaboration with France and Italy to produce anti-air warfare frigates.
SAMPSON | History
This detection and location method known today as radar, combined with a command and control system would act as a Force multiplier by allowing friendly fighters to know the exact location of enemy bombers and converge on them. On 26 February a successful demonstration of radar was given at Daventry, Northamptonshire. By the end of 1935 a system with a detection and location range of 100 km had been established, and plans were made in December to set up five fixed radar stations covering London airspace. One of these stations was to be located on the coast near Orford Ness, and Bawdsey Manor Research Station was set up there to become the main centre for all radar research.
Leonard George Chapman | Context of Chapman's work
Following delays and complications the UK withdrew and started its own Type 45 programme. The Type 45 destroyers use the SAMPSON radar with the PAAMS missile system, which was also developed for the Horizon frigates (French and Italian ships are to be fitted with the EMPAR MFR). The SAMPSON Radar is made in Cowes, Isle of Wight.
SAMPSON | History
Conventional radars, consisting of a rotating transmitter and sensor, have limited power, are vulnerable to enemy jamming and perform only one function - with separate units therefore required for surveillance, tracking and targeting. As an active array, SAMPSON uses software to shape and direct its beam allowing several functions to be carried out at once and, through adaptive waveform control, is virtually immune to enemy jamming. Active arrays have both longer range and higher accuracy than conventional radars. The beam-directing software uses sophisticated algorithms to schedule looks so that the potentially hundreds of active tracks are maintained with maximum accuracy.
SAMPSON | Operation
Bowen's job was to assemble a transmitter, managing quickly to raise the pulse-power to over 100 kilowatts. The first detection of an aircraft was made on 17 June 1935 at a range of 17 miles. By early 1936 after many improvements, aircraft were being detected at ranges of up to 100 miles. This caused work to be started on a chain of radar stations (Chain Home or CH), initially just covering the approaches to London. The team at Orfordness was enlarged as a result, and in March 1936 a new headquarters was acquired at Bawdsey Manor.
Edward George Bowen | Ground-based radar
Requiring a suitable receiver for such studies, he told the "new boy" Arnold Frederic Wilkins to conduct an extensive review of available shortwave units. Wilkins would select a General Post Office model after noting its manual's description of a "fading" effect (the common term for interference at the time) when aircraft flew overhead.
Radar | First experiments
This was the moment the British team had been waiting for. Edward George Bowen produced one of the earliest cavity magnetrons from a box and showed it to the other researchers. He explained that it also worked at 10 cm wavelength, but offered higher power - not just than the Navy klystrons, but even the US's existing long-wave radars. One US historian later described it as the "most valuable cargo ever brought to our shores".
SCR-584 radar | Background
By July 1940, samples of all of these devices had arrived at the TRE's experimental shops, along with more powerful magnetrons working between 5 and 10 kW. Herbert Skinner cobbled together the various parts on a table to produce the first working microwave radar. This used the updated NT98 magnetron that produced 5 kW of power. They demonstrated it by having someone ride a bicycle in front of the device while holding a metal plate acting as a reflector. This test demonstrated the new radar's ability to pick up targets even when they were very close to the horizon, something previous designs could not do.
Type 271 radar | Magnetron
In August 1937, the RDF development at HMSS changed, with many of their best researchers brought into the activity. John D. S. Rawlinson was made responsible for improving the Type 79X. To increase the efficiency, he decreased the frequency to 43 MHz ( 7 metre wavelength ). Designated Type 79Y, it had separate, stationary transmitting and receiving antennas.
History of radar | Royal Navy
After discussing this with his scientific assistant, Arnold F. 'Skip' Wilkins, Wilkins quickly produced a back-of-the-envelope calculation that showed the energy required would be enormous. Watt wrote back that this was unlikely, but added the following comment: "Attention is being turned to the still difficult, but less unpromising, problem of radio detection and numerical considerations on the method of detection by reflected radio waves will be submitted when required".
History of radar | United Kingdom
In 1931, at the Woolwich Research Station of the Army's Signals Experimental Establishment (SEE), W. A. S. Butement and P. E. Pollard had examined pulsed 600 MHz (50-cm) signals for detection of ships. Although they prepared a memorandum on this subject and performed preliminary experiments, for undefined reasons the War Office did not give it consideration. As the Air Ministry's work on RDF progressed, Colonel Peter Worlledge of the Royal Engineer and Signals Board met with Watson Watt and was briefed on the RDF equipment and techniques being developed at Orfordness. His report, “The Proposed Method of Aeroplane Detection and Its Prospects”, led the SEE to set up an “Army Cell” at Bawdsey in October 1936.
History of radar | British Army
Radio pioneer Guglielmo Marconi noticed radio waves were being reflected back to the transmitter by objects in radio beacon experiments he conducted on March 3, 1899 on Salisbury Plain. In 1916 he and British engineer Charles Samuel Franklin used short-waves in their experiments, critical to the practical development of radar. He would relate his findings 6 years later in a 1922 paper delivered before the Institution of Electrical Engineers in London:
History of radar | Guglielmo Marconi
The first development was a continuous-wave apparatus using Doppler-beat interference for detection. Kühnhold then shifted the GEMA work to a pulse-modulated system. Using a 50 cm (600 MHz) magnetron from Philips, their first transmitter was modulated with 2-μs pulses at a pulse repetition frequency (PRF) of 2000 Hz. The transmitting antenna was an array of 10 pairs of dipoles with a reflecting mesh, and the receiving antenna had three pairs of dipoles and incorporated lobe switching. The wide-band regenerative receiver used an RCA 955 acorn triode. A blocking device (a duplexer), shut the receiver input when the transmitter pulsed. A Braun tube was used for displaying the range.
Radar in World War II | Germany
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 distance.
History of radar | Telefunken
In February 1937, a developmental unit detected an aircraft at a range of 60 miles (96 km). The Air Ministry also adopted this system as a mobile auxiliary to the CH system.
History of radar | British Army
Newer techniques of VHF radio communications and direction-finding might also be used, but all of these methods were highly vulnerable to enemy interception. At the NTRI, Yoji Ito proposed that the UHF signal from a magnetron might be used to generate a very narrow beam that would have a greatly reduced chance of enemy detection. Development of microwave system for collision avoidance started in 1939, when funding was provided by the Imperial Navy to JRC for preliminary experiments. In a cooperative effort involving Yoji Ito of the NTRI and Shigeru Nakajima of JRC, an apparatus using a 3-cm (10-GHz) magnetron with frequency modulation was designed and built.
History of radar | Imperial Navy
In 1938, John F. Coales began the development of 600-MHz (50-cm) equipment. The higher frequency allowed narrower beams (needed for air search) and antennas more suitable for shipboard use. The first 50-cm set was Type 282. With 25-kW output and a pair of Yagi antennas incorporating lobe switching, it was trialed in June 1939. This set detected low-flying aircraft at 2.5 miles and ships at 5 miles. In early 1940, 200 sets were manufactured. To use the Type 282 as a rangefinder for the main armament, an antenna with a large cylindrical parabolic reflector and 12 dipoles was used. This set was designated Type 285 and had a range of 15 miles.
Radar in World War II | Air Search/Gunnery Director
The German inventor Christian Hülsmeyer was the first to use radio waves to detect "the presence of distant metallic objects". In 1904, he demonstrated the feasibility of detecting a ship in dense fog, but not its distance from the transmitter. He obtained a patent for his detection device in April 1904 and later a patent for a related amendment for estimating the distance to the ship. He also obtained a British patent on September 23, 1904 for a full radar system, that he called a "telemobiloscope". It operated on a 50 cm wavelength and the pulsed radar signal was created via a spark-gap.
Radar | First experiments
In February 1940, John Randall and Harry Boot at Birmingham University successfully ran the first cavity magnetron, eventually generating 1 kW at 9.8 cm (3,060 MHz). Supported by GEC, the device quickly developed into a practical 10 kW system, and several test units were available by May 1940. Microwave wavelengths are so much shorter than the Mk. IV's 1.5 m, fifteen times, that the dipole antennas required for reasonable gain were only a few inches long. This dramatically reduced the size of the system, allowing it to fit entirely in the nose of the aircraft. While a team under Herbert Skinner developed the electronics, Bernard Lovell was put in charge of examining the use of a parabolic dish to improve the directionality of the signal.
Airborne Interception radar | Mk. VIII
In 1946, Shearman began his career with the Admiralty Signal Establishment with a focus on high frequency communications following which he worked alongside Sir Robert Watson-Watt and Arnold Wilkins, considered to be the first radar pioneers in the UK. His early discoveries in short-wave radio (high-frequency radio waves) were able to accurately assess sea conditions. In 1957, Shearman tracked the satellite "Sputnik 1" and was able to greatly assist in the understanding of the ionosphere. He subsequently worked with the Royal Air Force and US Air Force before joining NASA for two years to help design the Alouette satellite which made further important advances in the understanding of the upper half of the ionosphere.
Ramsay Shearman | Career
Dee's 13 June description notes: Skinner also gave Dee fits with his unusual method of testing that the klystron was working properly, by using the output lead to light his cigarettes. GEC was working on producing a fully sealed version of the magnetron, as opposed to one that used an external vacuum pump. After inventing a new sealing method using gold wire and adapting the chamber of a Colt revolver as a drilling template, they produced the E1188 in early July 1940. This produced the same amount of power as the original Randall-Boot model, about 1 kW at around 10 cm.
AI Mk. VIII radar | First magnetron radar
However, during World War 2 John Randall and Harry Boot built on Hull's concept to develop the modern cavity magnetron, the first device which could produce high power at microwave frequencies, and the resulting centimeter-band radar proved a crucial advantage for the Allies in aerial warfare.
Albert W. Hull | Magnetron
Samuel of Bell Telephone Laboratories. However, the first truly successful example was developed by Aleksereff and Malearoff in USSR in 1936, which achieved 300 watts at 3 GHz (10 cm wavelength). The cavity magnetron was radically improved by John Randall and Harry Boot at the University of Birmingham, England in 1940. They invented a valve that could produce multi-kilowatt pulses at 10 cm wavelength, an unprecedented achievement. The high power of pulses from the device made centimeter-band radar practical for the Allies of World War II, with shorter wavelength radars allowing detection of smaller objects from smaller antennas. The compact cavity magnetron tube drastically reduced the size of radar sets so that they could be more easily installed in night-fighter aircraft, anti-submarine aircraft and escort ships.
Cavity magnetron | Introduction
They took over Oshchepkov's laboratory and were made responsible for all existing and future agreements for research and factory production. Writing later about the Purge and subsequent effects, General Lobanov commented that it led to the development being placed under a single organization, and the rapid reorganization of the work. At Oshchepkov's former laboratory, work with the 4 m (75 MHz) pulsed-transmission system was continued by A. I. Shestako. Through pulsing, the transmitter produced a peak power of 1 kW, the highest level thus far generated. In July 1938, a fixed-position, bi-static experimental system detected an aircraft at about 30 km range at heights of 500 m, and at 95 km range, for high-flying targets at 7.5 km altitude.
History of radar | Pre-war radio location systems
This was under E. Talbot Paris and the staff included Butement and Pollard. The Cell's work emphasize two general types of RDF equipment: gun-laying (GL) systems for assisting anti-aircraft guns and searchlights, and coastal- defense (CD) systems for directing coastal artillery and defense of Army bases overseas. Pollard led the first project, a gun-laying RDF code-named Mobile Radio Unit (MRU). This truck-mounted system was designed as a small version of a CH station. It operated at 23 MHz (13 m) with a power of 300 kW. A single tower supported a transmitting antenna, as well as two receiving antennas set orthogonally for estimating the signal bearing.
History of radar | British Army
Francis James Macdonald Farley FRS (13 October 1920 - 16 July 2018) was a British scientist. He was a Fellow of the Institute of Physics and an honorary fellow of Trinity College Dublin. He was educated at Clifton College and at Clare College, Cambridge. Farley obtained his PhD from Cambridge in 1950. During World War II he designed and made the first X-band microwave radar with 100 ns pulse and a one degree beam which directed the 15" guns at Dover. It showed shells splashing around the target. He invented clutter reference Doppler radar which could see vehicles on land and was used in Italy.
Francis Farley | Introduction
As early as 1937, Jones had suggested that a piece of metal foil falling through the air might create radar echoes. He, together with Joan Curran, was later instrumental in the deployment of "Window": strips of metal foil, cut to a length appropriate to the radar's wavelength, and dropped in bundles from aircraft, which then appeared on enemy radar screens as "false bombers". This technology is now known as chaff and contrary to the popular belief, was also known to the Germans at the time. Both parties were reluctant to use it out of fear that their enemy would do the same: This delayed its deployment for almost two years.
Reginald Victor Jones | Window
NEC assigned Kinji Satake of their Research Institute to develop a system called the Bi-static Doppler Interference Detector (BDID). For testing the prototype system, it was set up on an area recently occupied by Japan along the coast of China. The system operated between 4.0–7.5 MHz (75–40 m) and involved a number of widely spaced stations; this formed a radio screen that could detect the presence (but nothing more) of an aircraft at distances up to . The BDID was the Imperial Army's first deployed radio-based detection system, placed into operation in early 1941. A similar system was developed by Satake for the Japanese homeland.
History of radar | Imperial Army
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.
History of radar | Lorenz
They say the radar has a range of 6,000 km with targets between 0.1–0.12m. It can track 20 objects at the same time and can cope with four jamming sources. The designer, Viktor Ivantsov, was awarded the title "Hero of Labour" for his work on the Daryal. The first Daryal type radar was an active electronically scanned array built at Olenegorsk in 1977. It was the receiver building only and was called a Daugava rather than a Daryal. It used the transmitter of the adjacent Dnestr-M radar. Following this two Daryal radars were constructed in Pechora (1983) and Qabala (1985).
Daryal radar | Introduction
Appleton at King's College London. As part of his research, Bowen spent a large part of 1933 and 1934 working with a cathode-ray direction finder at the Radio Research Station at Slough, and it was there that he was noticed by Robert Watson-Watt and so came to play a part in the early history of radar. In 1935 he was recruited by Watson-Watt to work in the Radar Development Team as a Junior Scientific Officer.
Edward George Bowen | Early years
Even the earliest radar systems included a system to highlight a single selected target for further analysis. For instance, 1939's Gun-Laying Mark I, the British Army's first operational radar, used an on-screen cursor known as the "strobe" to highlight a single target. This worked by filtering out, or "gating", signals that were not within the strobe's short time period, typically a few microseconds, corresponding to a range of a few hundred meters. The signal within the strobe's window was then sent to secondary displays where two operators would determine the azimuth and elevation of that single target, by keeping its "blip" centered in their displays.
Range gate pull-off | Range gates and strobing
E. G. Bowen was responsible for developing the pulsed transmitter. On 17 June 1935, the research apparatus successfully detected an aircraft at a distance of 17 miles. In August, A. P. Rowe, representing the Tizard Committee, suggested the technology be code-named RDF, meaning Range and Direction Finding.
Radar in World War II | United Kingdom
In 1904, Christian Hülsmeyer gave public demonstrations in Germany and the Netherlands of the use of radio echoes to detect ships so that collisions could be avoided. His device consisted of a simple spark gap used to generate a signal that was aimed using a dipole antenna with a cylindrical parabolic reflector. When a signal reflected from a ship was picked up by a similar antenna attached to the separate coherer receiver, a bell sounded. During bad weather or fog, the device would be periodically spun to check for nearby ships. The apparatus detected the presence of ships up to , and Hülsmeyer planned to extend its capability to .
History of radar | Christian Hülsmeyer
In 1927, French physicists 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. These were still CW systems and depended on Doppler interference for detection. However, as most modern radars, antennas were collocated.
History of radar | France
Elkins was part of a team of Rome Air Development Center (RADC) engineers that developed and constructed components for frequency modulation/continuous wave (FM/CW) radars capable of detecting and tracking objects at over-the-horizon ranges. A prototype radar was installed and evaluated on 15 September 1970. The system incorporated a Beverage array receive antenna (located at Columbia Air Force Station), a high-power transmitter array (located at Moscow Air Force Station), and an operations center (located at Bangor Airport). This prototype became operational on 30 October of that year. Experimental transmissions from the Maine site covered a 60° sector from 16.5° to 76.5° azimuth and from 900 to 3,300 km in range from the radar.
Terence James Elkins | Development of the over-the-horizon air defence radar system
This system functioned as an early version of the modern anti-ballistic missile defence model. Statistical analysis was also employed to aid in the computation of the exact position of the enemy aircraft and to smooth the data acquired from the target due to signal fluctuations and noise effects.
Hendrik Wade Bode | First wireless feedback loop and robot weapons
The AI Mk. IV radar was the first operational airborne interception radar, first used experimentally in April 1940, and entering widespread service in early 1941. These systems used a set of four receiver antennas that were arranged so they were most sensitive in different directions; two were sensitive above or below the aircraft, and the other two to the left and right. The output from these antennas was rapidly switched back and forth on the display, producing two "blips" for any given target, with the length of the blip indicating the strength of the signal in that direction. By comparing the length of the blips from, say, the upper and lower antennas, the operator could determine if the target was above or below their fighter.
Serrate radar detector | Basic concept
It did not provide range (distance) information, only warning of a nearby object. He patented the device, called the "telemobiloscope", but due to lack of interest by the naval authorities the invention was not put into production. Hülsmeyer also received a patent amendment for estimating the range to the ship. Using a vertical scan of the horizon with the "telemobiloscope" mounted on a tower, the operator would find the angle at which the return was the most intense and deduce, by simple triangulation, the approximate distance. This is in contrast to the later development of pulsed radar, which determines distance via two-way transit time of the pulse.
History of radar | Christian Hülsmeyer
Sure enough, Metrovick returned a design based on this model, which proved useless. The team also contacted Cossor and provided complete details of the required design, but when they returned their first attempt six months later it was completely unusable. When they asked for improvements, Cossor never responded, too busy with other work. While waiting for the Metrovick and Cossor receivers to arrive, there was a chance encounter between Bowen and his former professor at King's College, Nobel prize winner Edward Appleton. In early 1939, Appleton mentioned to Bowen that Pye Electronics had also been interested in the BBC's experimental 45 MHz television service and had built receivers that they still might have on-hand.
ASV Mark II radar | New tubes
Within a short time, he was authorized to set up a development laboratory for this in the NRC Radio Section. Its first project was the development of s surface-warning radar system for the Royal Canadian Navy. Using commercial components and with essentially no further assistance from Great Britain, a system was developed to protect the entrance to the Halifax Harbour, called Night Watchman, tested in June 1940. This was followed by a ship-borne system designated Surface Warning 1st Canadian (SW1C) completed in May 1941. In the summer of 1940, Great Britain was at the limit of production capability and desperately needed allies for her war effort.
John Tasker Henderson | Second World War
A simple wave-interference apparatus can detect the presence of an object, but it cannot determine its location or velocity. That had to await the invention of pulsed radar, and later, additional encoding techniques to extract this information from a CW signal. When Taylor's group at the NRL were unsuccessful in getting interference radio accepted as a detection means, Young suggested trying pulsing techniques. This would also allow the direct determination of range to the target. In 1924, Hyland and Young had built such a transmitter for Gregory Breit and Merle A. Tuve at the Carnegie Institution of Washington for successfully measuring the height of the ionosphere.
History of radar | United States Navy
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 . 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.
History of radar | Netherlands
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.
History of radar | Telefunken
The Royal Navy learned of Robert Watson-Watt's radar experiments in 1935 and began exploring the use of radar for naval uses very quickly. In contrast to the Air Ministry, which had no formal electronics establishment at the time, the Navy's Experimental Department in Portsmouth was a powerhouse in electronics design and was able to quickly develop a series of radars for naval use. In 1938, their Type 79 radar was the first naval radar to enter service. At the time, the only high-power radio frequency electronics operated in the shortwave bands, with wavelengths measured in metres. Existing valves (vacuum tubes) could operate at an absolute maximum of 600 MHz (50 cm wavelength), but operation anywhere near this range resulted in very low efficiency and output power.
Type 271 radar | Background
The early RDF developments in Canada were at the Radio Section of the National Research Council of Canada. Using commercial components and with essentially no further assistance from Britain, John Tasker Henderson led a team in developing the Night Watchman, a surface-warning system for the Royal Canadian Navy to protect the entrance to the Halifax Harbour. Successfully tested in July 1940, this set operated at 200 MHz (1.5 m), had a 1 kW output with a pulse length of 0.5 μs, and used a relatively small, fixed antenna. This was followed by a ship-borne set designated Surface Warning 1st Canadian (SW1C) with the antenna hand-rotated through the use of a Chevrolet steering wheel in the operator's compartment.
History of radar | Others
On the outbreak of the Second World War, Bowen's unit was moved to St Athan. One of the first things that Bowen did there was to try to detect a submarine by radar. By then, the cavity magnetron had been improved by John Randall and Harry Boot, making airborne radar a powerful tool. By December 1940, operational aircraft were able to detect submarines at up to 15 miles range. This technology had a major effect on winning the Battle of the Atlantic and eventually enabled forces to be built up by sea for the invasion of Europe. In April 1941, RAF Coastal Command was operating anti-submarine patrols with about 110 aircraft fitted with radar.
Edward George Bowen | Second World War
The introduction of the cavity magnetron in 1940 led to a revolution in radar design. A simple device the size of a fist generated tens of kilowatts of radio energy, rivalling some of the most powerful room-filling broadcasters. More importantly, it operated at wavelengths that were much shorter than any existing system; at ~10 cm, the antennas were only a few centimetres long, making them very easy to fit on aircraft and small vehicles. They were so small that it became practical to use a parabolic reflector to focus them, producing beams only a few degrees wide from an assembly perhaps a meter across, or smaller.
Radar, Anti-Aircraft No. 3 Mk. 7 | GL Mk. III
In British service, the radars were used in the Falkland Islands in 1982, the Gulf War in 1991 and in the Balkans. He is listed in patents for electric servomotor systems and for control of automatic machine tools when he worked at EMI.
Geoffrey H. Stephenson | Engineering
The radar signal was locked on target and its data was wirelessly transmitted to a ground receiver that was connected to the artillery servomechanism feedback control system, causing the servo to accurately modify its angular position and maintain it for an optimum amount of time, long enough to fire at the calculated (predicted) coordinates of the target and thus successfully track the target. The prediction of the coordinates was the function of Director T-10, a form of electrical computer so named because it was used to direct the positioning of the gun with respect to the airborne target. It also calculated the target average velocity based on the location information provided by the radar and predicted the future target location based on its assumed flightpath equation, usually a linear function of time.
Hendrik Wade Bode | First wireless feedback loop and robot weapons
Hugh Dowding had already seen the value of radar for his Air Defence system. Developments progressed at Bawdsey Manor from the mid-1930s; the early ground-based radar chains worked well but needed to be improved in accuracy, and Dowding saw the need for an airborne radar. At Bawdsey, Taffey Bowen had also needed a wideband valve for Airborne Interception (AI) radar; he had just one working set. So he contacted Tom Goldup, a senior director of Mullard, and "quite by chance in April or May of 1939" he heard of the Pye set from his old Professor at King's College, Edward Appleton.
EF50 | Radar uses
The Americans perfected and mass-produced the fuse. In due course, these proximity fuses arrived in the United Kingdom, where they played an important part in the defence of the kingdom against the V-1 flying bomb. Strothers married Curran on 7 November 1940. Soon afterwards they were transferred to the Telecommunications Research Establishment near Swanage, where Sam worked on centimetric radar, while Joan joined the Counter Measures Group in an adjoining lab. It was with this group, at Swanage, and later at Malvern, that Joan devised the technique that was codenamed Window, which is also known as chaff. She tried various types of radar reflectors, including wires and sheets, before settling on strips of tin foil wide and long that could be scattered from bombers, thus disrupting the enemy's radar.
Joan Curran | Second World War
In September of that year, a British delegation, the Tizard Mission, revealed to US and Canadian researchers that they had developed a magnetron oscillator operating at the top end of the UHF band (10 cm wavelength/3 GHz), allowing greatly increased accuracy. Bush organized the Radiation Laboratory (Rad Lab) at the MIT to develop applications using it. This included a new short-range air-defense radar. Alfred Lee Loomis, running the Rad Lab, advocated the development of an entirely automatic tracking system controlled by servomechanisms. This greatly eased the task of tracking targets and reduced the manpower needed to do it. They were also able to take advantage of a newly developed microwave switch that allowed them to use a single antenna for broadcast and reception, greatly simplifying the mechanical layout.
SCR-584 radar | Introduction
The British Army's first radars were intended to measure the distance to aircraft as an aiming aid for anti-aircraft artillery. In the 1930s, measuring the angle to the target was easily accomplished with optical instruments, but rangefinding remained a time-consuming and inaccurate process. This led to the creation of the GL Mk. I radar which was introduced in 1939. It quickly became clear that a range-only system was wasting considerable utility inherent to the design. Since the radar's signal spread over about 20 degrees, it observed a wide area of the sky and was able to detect targets before the crews on the optical instruments could.
Radar, Anti-Aircraft No. 3 Mk. 7 | GL Mk. I & II
This produced a display indicating the direction to the German aircraft, but not the range. When the operator felt the range to be suitable, the display was reconnected to the Mk. IV's own electronics to provide both ranging and directional information during the last moments of the attack. Serrate operations began by No. 141 Squadron RAF on the night of 7 September 1943. 179 operational sorties yielded 14 claimed fighters shot down, for 3 losses. After that point, the Luftwaffe realized what was happening and quickly introduced new versions of their radars working on different frequencies. Unlike the earlier sets, which just happened to operate on frequencies very close to the British radars, the new sets required entirely new detectors, which took some time to develop.
Serrate radar detector | Introduction
The first mechanically scanned phased array radar (using a rotating Yagi antenna) was demonstrated in the 1930s. The first electronically scanned radars used electromechanical devices (such as mechanical tuners or switches) to steer the antenna's beam. Germany built the Wullenweber circular array for direction finding during the early years of World War II. The Wullenweber could electronically scan the horizon 360° and determine the direction of any signal with reasonably good accuracy. Circular arrays were enhanced during the Cold War for eavesdropping purposes. The American Physicist Luis Walter Alvarez developed the first ground-controlled approach (GCA) system for landing aircraft in bad weather based on an electronically steered microwave phased array antenna.
History of smart antennas | Phased array radar
The critical problem of submarine detection required RDF systems operating at higher frequencies than the existing sets because of a submarine's smaller physical size than most other vessels. When the first cavity magnetron was delivered to the TRE, a demonstration breadboard was built and demonstrated to the Admiralty. In early November 1940, a team from Portsmouth under S. E. A. Landale was set up to develop a 10-cm surface-warning set for shipboard use. In December, an experimental apparatus tracked a surfaced submarine at 13 miles range. At Portsmouth, the team continued development, fitting antennas behind cylindrical parabolas (called "cheese" antennas) to generate a narrow beam that maintained contact as the ship rolled.
Radar in World War II | Microwave Warning/Fire Control
In February 1940, Great Britain developed the resonant-cavity magnetron, capable of producing microwave power in the kilowatt range, opening the path to second-generation radar systems.
Radar in World War II | Introduction
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.
History of radar | GEMA
The history of radar (where radar stands for RAdio Detection And Ranging) started with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell's seminal work on electromagnetism. However, it was not until the early 20th century that systems able to use these principles were becoming widely available, and it was German inventor Christian Hülsmeyer who first used them to build a simple ship detection device intended to help avoid collisions in fog (Reichspatent Nr. 165546). Numerous similar systems, which provided directional information to objects over short ranges, were developed over the next two decades.
History of radar | Introduction
In 1915, Robert Watson Watt joined the Meteorological Office as a meteorologist, working at an outstation at Aldershot in Hampshire. Over the next 20 years, he studied atmospheric phenomena and developed the use of radio signals generated by lightning strikes to map out the position of thunderstorms. The difficulty in pinpointing the direction of these fleeting signals using rotatable directional antennas led, in 1923, to the use of oscilloscopes in order to display the signals. The operation eventually moved to the outskirts of Slough in Berkshire, and in 1927 formed the Radio Research Station (RRS), Slough, an entity under the Department of Scientific and Industrial Research (DSIR).
History of radar | United Kingdom
The main radar would be used solely for surveillance, with target illumination being left to existing radar systems used with earlier missiles like the RIM-8 Talos or RIM-24 Tartar. During development it was found that attempting to use a single antenna for both search and tracking did not work effectively, so the system was modified to use two antennas, one for surveillance and another for tracking. Thus the system ended up using three radar antennas, and was, therefore, similar to earlier systems. An automatic tracking computer was added to the system in 1967. Also, in 1967, USS "Long Beach" detected and destroyed two North Vietnamese MiGs, utilizing the SCANFAR and Talos missile systems.
SCANFAR | History
It was recognized that detection also needed range measurement, and funding was provided for a pulsed transmitter. This was assigned to a team led by Robert M. Page, and in December 1934, a breadboard apparatus successfully detected an aircraft at a range of one mile. The Navy, however, ignored further development, and it was not until January 1939, that their first prototype system, the 200-MHz (1.5-m) "XAF", was tested at sea. The Navy coined the acronym RAdio Detection And Ranging (RADAR), and in late 1940, ordered this to be exclusively used. Taylor's 1930 report had been passed on to the U.S.
Radar in World War II | United States of America
The AN/FPS-7 Radar was a Long Range Search Radar used by the United States Air Force Air Defense Command. In the mid-1950s General Electric developed a radar with a search altitude of 100,000 feet and a range of 270 miles. This radar was significant in that it was the first stacked-beam radar to enter into production in the United States. The antenna was fed signals from several feed horns arranged in a vertical stack, producing a series of horizontal beams separated vertically in space. By comparing the returns from the different feeds, altitude information could be determined without the need for a separate height-finder radar.
General Electric AN/FPS-7 Radar | Introduction
Bell Labs proposed replacing the Nike Zeus radars with a phased array system in 1960, and was given the go-ahead for development in June 1961. The result was the Zeus Multi-function Array Radar (ZMAR), an early example of an active electronically steered array radar system. ZMAR became MAR when the Zeus program ended in favor of the Nike-X system in 1963. The MAR (Multi-function Array Radar) was made of a large number of small antennas, each one connected to a separate computer-controlled transmitter or receiver. Using a variety of beamforming and signal processing steps, a single MAR was able to perform long-distance detection, track generation, discrimination of warheads from decoys, and tracking of the outbound interceptor missiles.
Active electronically scanned array | History
Squadron Leader Leonard George Chapman (28 March 1910 – 25 July 1975) was an inventor, radio engineer and Royal Air Force officer. While serving in the Royal Air Force he invented the 'Chapman Method' in 1937–1938. This method accurately determines the location of an object from the time difference of arrival of a signal (possibly radio echo) emitted from that object to three or more receivers. A method commonly used in civil and military surveillance applications, and also known as Multilateration. Thus it has been suggested that Chapman be nominated as the father of Multilateration. Chapman was in charge of installing 5 radar stations as part of the Chain Home system.
Leonard George Chapman | Introduction
By June they were detecting aircraft at 27 km, which was enough for scientists and engineers to stop all work on competing sound-based detection systems. The successful results of the initial test led to the setting up of a research station that was to become the Telecommunications Research Establishment (TRE). By the end of the year the range was up to 100 km, at which point plans were made in December to set up five stations covering the approaches to London by Watson-Watt and Sir Henry Tizard. Those stations opened in 1938 with the help of Wilkins and were further extended to the Chain Home system.
Arnold Wilkins | Radar
Based on the success of these early experiments, the Department of Defense proposed to deploy a fully operational radar system. This radar system, covering 180° in azimuth, was built at the same locations in Maine. Initial testing was conducted from June 1980 to June 1981. GE Aerospace (now Lockheed Martin Ocean, Radar and Sensor Systems) received a contract in mid-1982 for full-scale development of the AN/FPS-118 program. The operational system consisted of multiple OTH-B radars functioning as an early warning system, to detect incoming enemy bombers and cruise missiles. The system, as initially envisioned, was to consist of four sectors:
Terence James Elkins | Development of the over-the-horizon air defence radar system
The earliest concerted effort to develop radar in the UK dates to 1935, and Robert Watt replied to an Air Ministry question about radio-based death rays by stating they were impossible, but using radio as a detection means was possible. After a simple practical demonstration, a prototype system was built at Orfordness on the east coast of England. While on a Sunday drive in the area, Watt noticed the large and unused Bawdsey Manor, and this was leased by the Air Ministry to become first radar research centre in the country. Soon after taking over Bawdsey in 1936, the British Army heard of their efforts and formed a group to work with them to develop ground-based applications.
Royal Radar Establishment | Administrative history
While testing the AI radars near Bawdsey Manor, Bowen's team noticed the radar generated strong returns from ships and docks. This was due to the vertical sides of the objects, which formed excellent partial corner reflectors, allowing detection at several miles range. The team focussed on this application for much of 1938. The Air-Surface Vessel Mark I, using electronics similar to those of the AI sets, was the first aircraft-carried radar to enter service, in early 1940. It was quickly replaced by the improved Mark II, which included side-scanning antennas that allowed the aircraft to sweep twice the area in a single pass.
Radar in World War II | Air-Surface Vessel
In February 1940, John Randall and Harry Boot built a working cavity magnetron, which soon produced 1 kW of power at a wavelength of only 10 cm from a device about the size of a shoe box. A half-wave dipole for this wavelength was only long, and could easily be fitted to almost any ship or aircraft. It represented an enormous leap in performance, and microwave radar development by all of the forces began immediately. While the magnetron solved the problem of generating short-wavelength signals with high power, that alone does not make a complete radar system. One also needs a radio signal detector that can operate at equally high frequencies, cables capable of carrying that signal to the antenna efficiently, and a host of other developments.
Type 271 radar | Magnetron
In the late 1930s the UK was working on a variety of developments to increase air defence efficiency The first radar proximity fuze was proposed by Butement, Edward S. Shire, and Amherst F.H. Thompson, in a memo to the British Air Defence Establishment in May 1940. A breadboard circuit was constructed by the inventors and the concept was tested in the laboratory by moving a sheet of tin at various distances. Early field testing connected the circuit to a thyratron trigger operating a tower-mounted camera which photographed passing aircraft to determine distance of fuze function. Prototype fuzes were then constructed in June 1940, and installed in "unrotated projectiles", the British cover name for solid fueled rockets, and fired at targets supported by balloons.
Proximity fuze | Design in the UK
In contrast, a radar with a 10 cm wavelength can detect objects 10 cm in size with a reasonably-sized antenna. The cavity magnetron was perhaps the single most important invention in the history of radar. In the Tizard Mission during September 1940, it was given free to the U.S., along with other inventions, such as jet technology, in exchange for American R&D and production facilities; the British urgently needed to produce the magnetron in large quantities. Edward George Bowen was attached to the mission as the RDF lead. This led to the creation of the Radiation Laboratory (Rad Lab) based at MIT to further develop the device and usage.
Radar in World War II | Centimetric
In 1947, the Royal Aircraft Establishment (RAE) was handed the task of developing guided missiles, taking over from a previously diverse group of efforts. Several engineers from the RRDE were sent to the RAE at Farnborough Airport to aid the design of the tracking and guidance systems. Among the group was George Clarke, who had worked on the LOPGAP missile guidance system but was more interested in advanced radar development. In 1949 Clarke invented a novel sort of identification friend or foe (IFF) system that did not have to be triggered by a pulse sent from the ground. Instead, each airborne IFF would broadcast signals at random times.
RX12874 | Correlation radar
1949 to 1952 — After graduating from MIT, Howlett supported himself and a wife and daughter by creating his first enterprise, repairing TV sets in the home, and by designing and building electronic prototypes—one of which had a proximity detector that caused a dummy to talk to you in a store when you walked up to it. 1952 to 1957 — Staff member at MIT's Lincoln Laboratory working on cross-correlation radar. 1957 to 1960 — General Electric heavy military electronics in Syracuse, NY, as an engineer, traveling worldwide to trouble shoot and educate operators of an early warning radar system.
Eric Howlett | Career
One of the first projects was to build equipment to transition from the British long-wave radar to the new microwave centimeter-band radar made possible by the cavity magnetron. In working on the Microwave Early Warning system (MEW), Alvarez invented a linear dipole array antenna that not only suppressed the unwanted side lobes of the radiation field, but also could be electronically scanned without the need for mechanical scanning. This was the first microwave phased-array antenna, and Alvarez used it not only in MEW but in two additional radar systems. The antenna enabled the Eagle precision bombing radar to support precision bombing in bad weather or through clouds.
Luis Walter Alvarez | Radiation Laboratory
In 1962, Marchetti, Inc., was formed in Natick, Massachusetts, with the primary objective of performing research and development on advanced radars. One of the first contracts was from RADC for designing and fabricating a wide-bandwidth radar transmitter. This operated between 1.224 and 1.386 GHz in the L-band using two traveling-wave tubes that produced 10-kW peak power. This was completed in 1963. Another early contract from RADC was for developing a radar facility at the White Sands Missile Range, New Mexico, for re-entry measurements. For this, a 100-MHz AN/TPQ-20 radar was rebuilt with five Yagi antennas to receive vertically and horizontally polarized signals reflected from a test vehicle.
John W. Marchetti | Marchetti, Inc
The Salisbury screen was a way of reducing the reflection of radio waves from a surface. It was one of the first concepts in radar absorbent material, an aspect of "stealth technology", used to prevent enemy radar detection of military vehicles. It was first applied to ship radar cross section (RCS) reduction. The Salisbury screen was invented by American engineer Winfield Salisbury in the early 1940s (see patent filing date). The patent was delayed because of wartime security.
Salisbury screen | Introduction
Boole's grandson, the physicist G. I. Taylor, made significant experimental contributions to quantum mechanics. The first practical demonstration of radar was near Daventry in 1935. Robert Robinson, of Chesterfield in Derbyshire, invented the circular symbol in 1925 for the pi bonds of the benzene ring, as found on all structural diagrams of aromatic compounds. Nicola Pellow, a maths undergraduate at Leicester Polytechnic, whilst at CERN in November 1990, wrote the world's second web browser.
East Midlands | Scientific heritage
Though these may be considered the most significant, many other items were also transported, including designs for rockets, superchargers, gunsights and submarine detection devices. He returned to Britain in December 1940. Soon after his return, Cockcroft was appointed Chief Superintendent of the Air Defence Research Development Establishment (ADRDE) at Christchurch, Hampshire. His focus was on the use of radar for shooting down enemy aircraft. The GL Mk. III radar was developed as a target tracking and predicting radar, but by 1942 the SCR-584 radar developed for the same purpose in the United States became available, and Cockcroft recommended that it be acquired under Lend-Lease.
John Cockcroft | Second World War
In 1938, he helped to develop the British version of the Identification friend or foe (IFF) system. After the war, he worked at the "Radio Research Statio"n in Buckinghamshire. His memoirs were written in 1976 and lodged in Churchill College Library, Cambridge.
Arnold Wilkins | Radar
Marconi was the leading supplier of ground-based radars in the UK for many years, mostly working with designs developed at the Royal Radar Establishment (RRE) and its predecessors. These generally used large radars for 2D scanning to a plan-position indicator (PPI) display and separate height finding radars for measuring target altitudes. In the early 1960s, the company carried out several industry studies to better understand the future market. A new product concept emerged from this process, a long-range air-scanning radar to provide battlefield overview and early warning, what the British Army called a tactical control radar. The key feature was mobility; the design had to be able to be pulled by Land Rovers, slung under a Sea King helicopter, and fit within a single C-130 Hercules aircraft.
Marconi Martello | S600
By late 1941 a new generation of radars were appearing that were based on the new cavity magnetron instead of the traditional tube-based electronics of the Mk. IV. These operated at much shorter wavelengths, about 9 cm, thus requiring much smaller antennas while also providing much higher angular resolution. The production AI Mk. VIII radar version became widespread by late 1942 and were installed primarily on the de Havilland Mosquito, leaving the problem of what to do with the older Bristol Beaufighters mounting Mk. IV. This difficulty arose at the time that the use of the H2S radar was being debated within Bomber Command, with concern being expressed that an aircraft lost over Europe would reveal the secret of the magnetron to the Germans.
Serrate radar detector | Basic concept
The Royal Navy's first successful RDF was the "Type 79Y Surface Warning", tested at sea in early 1938. John D. S. Rawlinson was the project director. This 43-MHz (7-m), 70-kW set used fixed transmitting and receiving antennas and had a range of 30 to 50 miles, depending on the antenna heights. By 1940, this became the "Type 281", increased in frequency to 85 MHz (3.5 m) and power to between 350 and 1,000 kW, depending on the pulse width. With steerable antennas, it was also used for Gun Control. This was first used in combat in March 1941 with considerable success.
Radar in World War II | Surface Warning/Gun Control
The Royal Navy, however, required more capable ships which could throw a large defensive "bubble" over a fleet operating in hostile areas. The compromise which largely solved this problem was the adoption of a standard radar interface which allowed France and Italy to install the EMPAR multi-function passive electronically scanned array radar and the UK to install the more capable SAMPSON active electronically scanned array radar – the SAMPSON radar has a higher data rate and an adaptive beam that allows a greater ability to track multiple targets, long-range detection of low-RCS targets, a lower false-alarm rate, and overall higher tracking accuracy.
Horizon-class frigate | Development
Jennison was born in Grimsby, England, in 1922. His education was at Clee Grammar School for Boys. He was commissioned from RAF aircrew to the Technical Branch-Signals, where he developed radar and microwave systems using the Magnetron.
Roger Clifton Jennison | Early life
In March 1936, the work at Orfordness was moved to Bawdsey Manor, nearby on the mainland. Until this time, the work had officially still been under the DSIR, but was now transferred to the Air Ministry. At the new Bawdsey Research Station, the Chain Home (CH) equipment was assembled as a prototype. There were equipment problems when the Royal Air Force (RAF) first exercised the prototype station in September 1936. These were cleared by the next April, and the Air Ministry started plans for a larger network of stations. Initial hardware at CH stations was as follows: The transmitter operated on four pre-selected frequencies between 20 and 55 MHz, adjustable within 15 seconds, and delivered a peak power of 200 kW.
History of radar | Air Ministry
With this success, Lovell and a new addition to the Airborne Group, Alan Lloyd Hodgkin, began experimenting with horn-type antennas that would offer significantly higher angular accuracy. Instead of broadcasting the radar signal across the entire forward hemisphere of the aircraft and listening to echoes from everywhere in that volume, this system would allow the radar to be used like a flashlight, pointed in the direction of observation. This would greatly increase the amount of energy falling on a target, and improve detection capability. On 21 February 1940, John Randall and Harry Boot first ran their cavity magnetron at 10 cm (3 GHz).
AI Mk. IV radar | AIS, replacement
The Royal Air Force's first Airborne Intercept radars operated in the 1.5 meter band and featured antennas similar to their later German counterparts. However, the introduction of the cavity magnetron in 1940 changed things dramatically. The magnetron efficiently generated microwaves from a device the size of a coffee tin, lowering operational wavelengths from the several-meter range to less than 10 centimeters. This reduced the antenna size to a few centimeters. Instead of simply using a smaller Yagi antenna, the system was paired with a new parabolic dish which allowed for conical scanning. The result was a small, lightweight, powerful, long range and easy to read radar.
FuG 240 Berlin | Rotterdam Device
At the outbreak of the Second World War, Cockcroft took up the post of Assistant Director of Scientific Research in the Ministry of Supply, working on radar. In 1938, Sir Henry Tizard showed Cockcroft Chain Home, the ring of coastal early warning radar stations built by the Royal Air Force (RAF) to detect and track aircraft. Now, he helped deploy scientists to help get the system fully operational. In 1940, he became part of the Advisory Council for Scientific Research and Technical Development. In April 1940, along he became a member of the Committee for the Scientific Study of Air Warfare formed to handle issues arising from the Frisch–Peierls memorandum, which calculated that an atomic bomb could be technically feasible.
John Cockcroft | Second World War
Prior to the development of SCANFAR, the Navy had been developing an advanced anti-aircraft weapon system combining an extremely advanced radar system, the AN/SPG-59, with a new long-range missile known as the RIM-50 Typhon. The radar was an active electronically scanned array that acted both as a long-range surveillance system as well as the target illumination and guidance system for the missiles. The system proved to be beyond the state of the art, in particular it required a large number of individual broadcast elements that proved to be unreliable and expensive. SCANFAR was to some extent a simplified version of the SPG-59.
SCANFAR | History
The original design adopted a layout similar to that of AN/APQ-53 radar of MIM-104 Patriot, with a main S-band array with a total of 3456 transceivers and a small C-band array to control HQ-9 SAM including such as TVM, ARH and SARH. The design was tentatively approved by PLAN for the initial two hundred kilometer range requirement, but after further discussion, the 14th Institute was tasked to upgrade the design to extend the maximum range to three hundred kilometers by the PLAN evaluation team headed by rear admiral Zhao Deng-Ping (赵登平), the son-in-law of late Senior General Chen Geng.
Type 346 radar | Initial phase
In his mid-twenties he designed a range-finding system which allowed guns to home in on enemy ships beyond the horizon with accuracy and to fire a salvo the instant they were detected. His achievements won recognition from the British Government in the form of a large cash award, similar to that given to Sir Frank Whittle, inventor of the jet engine. At the outbreak of war he was seconded to the Admiralty to work on the development of radar. He resolved the key component of a design for a radar distance-measuring oscillator, a problem which at the time was defeating the young Herman Bondi and Fred Hoyle, part of the mathematical team backing up the radar designers.
Coppy Laws | Work
In the autumn of 1922, Albert H. Taylor and Leo C. Young at the U.S. Naval Aircraft Radio Laboratory were conducting communication experiments when they noticed that a wooden ship in the Potomac River was interfering with their signals. They prepared a memorandum suggesting that this might be used for ship detection in a harbor defense, but their suggestion was not taken up. In 1930, Lawrence A. Hyland working with Taylor and Young, now at the U.S. Naval Research Laboratory (NRL) in Washington, D.C., used a similar arrangement of radio equipment to detect a passing aircraft. This led to a proposal and patent for using this technique for detecting ships and aircraft.
History of radar | United States Navy
Birmingham's Mark Oliphant initially attacked the problem by attempting to further develop the klystron, a pre-war invention that was one of the first successful microwave-frequency tubes. In spite of many attempts, by the end of 1939 their best klystrons were generating only 400 watts, far below what would be needed for radar use. Two minor members of the team, John Randall and Harry Boot, had been asked to look at another concept which also failed to mature. Left with little to do, they begin considering alternative solutions. They struck upon the idea of using multiple resonant cavities arranged in a circle outside a common central core, as opposed to the klystron's linear arrangement.
GL Mk. III radar | Magnetrons
Late in 1957, the Royal Aircraft Establishment began work with both Bristol Aerospace and Ferranti for alternatives to the EE/Marconi designs. Bristol responded in early 1958 with the first definitive design for such a system. This would use the Red Duster Series 2 Mark 2, later to be known as Bloodhound Mk. 3, combined with the Type 85 radar for early warning, Type 86 for terminal tracking and FPS-16 for midcourse tracking. In action, the Type 85 would detect the missile while it was launching, and then cue one of the UK-based FPS-16's onto it. These radars would track the booster as it launched, determining the trajectory and probable impact point.
Violet Friend | Violet Friend
The first mode is used for target detection and monitoring of the traffic condition on the indicator, the second—for the detection of targets in specific sector before going to the auto maintenance and for coarse positioning, the third—to accurately determine the azimuth and elevation in automatic mode and manual slant range or semi-automatic way. Since 1956 Samuel P. Rabinovich is chief designer of the radar sighting of interceptor missiles and command transfer station (RSVPR) experimental missile defense system (NMD). Fully missile defense system first tested in March 1961 had shown the fundamental possibility of defeat warheads of ballistic missiles. This achievement had risen in a row with the launch of the first Sputnik, the first cosmonaut, and other accomplishments, which showed the highest scientific, technical and organizational level of defense enterprises and organizations of the Ministry of Defence.
Samuel Rabinovich | Biography
Some success was made in the infrared detection, but little was accomplished using radio. In 1932, progress at the Naval Research Laboratory (NRL) on radio interference for aircraft detection was passed on to the Army. While it does not appear that any of this information was used by Blair, the SCL did undertake a systematic survey of what was then known throughout the world about the methods of generating, modulating, and detecting radio signals in the microwave region.
History of radar | United States Army