Linesman/Mediator - Knowledge

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training role of the School of Fighter Control. The L1 got three more computers (Elliott Argus 500s) as the Recognised Air Picture Dissemination System (RAPiDS) and these disseminated the RAP out from the L1 in a more advanced format. Though the concepts remained valid, the technology used to route the radar signals was out-of-date long before the system was completed. Having the control of aircraft centralised in one place also put it at high risk. A change of plan moved the interception roles out to two of the main radar stations, where the RAP from the L1 was used to monitor the airspace while the Fighter Controllers then used the Standby Local Early Warning and Control Systems (SLEWC based on Elliott 920C computers) to

499:. It noted that missiles able to reach the UK from eastern Europe were already available, and by the mid-1960s these would be armed with strategic weapons with enough accuracy to attack the bomber bases. Although a Soviet bomber attack was still possible, especially low-altitude sneak attacks, such attacks would simply portend the arrival of the missiles – there was no credible scenario where the Soviets used an all-bomber attack, if they released their strategic weapons they would use all of them. 911:"Blue Yeoman" radar operated in the "S" band part of the spectrum. By comparison with the Type 84 it was massive, a MOPA system with 12 klystron transmitters and 60 receivers. The equipment was housed in the main technical block for the Radar site, the R12 building, the aerial being mounted on top of the building. The Type 85 ended up using the same design of antenna as the T84, although only "one side" of it, the aerial for the associated secondary radar being mounted underneath, rather than above. 1004:

was sent over microwave link. For example, the Type 85 at Neatishead used the signals captured from the high speed aerial at Staxton Wold to detect jamming aircraft. Each Type 85 with its associated high speed aerial was able to provide a PD baseline of several hundred miles to the north and south. There was a high speed aerial situated at Dundonald Hill in Ayrshire, Scotland which provided a baseline to the north of RAF Boulmer, but there was no similar extension to the south of RAF Neatishead.

892: 25: 918:. The radar had 12 transmitters which were grouped in four bands, A, B, D & E. Each transmitter had a peak power output of 5 MW, giving 60 MW total power output, this massive power was routed through waveguide switches that enabled the aerial to produce a standard "cosec squared" beam or, in conditions of intense ECM the power concentrated into a beam 6 degrees high aimed at the target. 605:, which would significantly reduce the cost of the telecommunications equipment. This led to a firestorm of protest within the RAF, because while it was true this would help communications with the civilian network, it made communications with the military radars more difficult, potentially able to be jammed. The argument over this issue raged, but no changes were made in the immediate term. 424:

10 Watt per megahertz of bandwidth. If the receiver carefully filtered the return signal tightly around the broadcast frequency, it might only receive a few watts of jamming. With enough transmitted power, on the order of 10 MW, the signal reflected off a target at 200 miles would be about 11 W, thereby allowing the radar's signal to remain visible.

354: 937:. Data from the radar was passed to the Automatic Height Finder which compared comparative strength of returns from a target between beams. Given the range and known angle it is a simple process to calculate height. However this was being done hundreds of times a second on multiple targets, in the late 1960s and early 1970s it was a considerable feat. 428:

accomplished with the magnetron, whose output frequency is a function of its physical construction, but this was possible using new high-power klystrons. This possibility was developed under the name "Blue Riband", using twelve klystrons that were randomly mixed together to produce an output signal on two widely separated frequencies.

447:" that used two widely separated antennas, several correlators, and a computer to calculate the location of the jammer. It was later noted that one of the two antennas could be the Blue Riband, thereby reducing the number of new sites that had to be built. Winkle proved itself able to track the jammer even while it was below the 711:

in the London area. Here the main manufacturers (Plessey – data processing, and Marconi – displays) carried out enhanced development. Each of the Linesman sites was able to operate on its own, but the network was intended to be controlled from the centralized "L1" site (now at West Drayton). Each of

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The solution to this problem was to build a much smaller defensive network with enough performance to attack a jammer aircraft while it was still far enough away that the BMEWS would still be operational. This led to a new Ahead layout in 1958 with three stations arranged in a triangle covering the V

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To test whether such a system would actually be effective, the RAF purchased a carcinotron from CSF and fit it to an aircraft christened "Catherine". In tests beginning in late 1954, the jammer proved to be able to render the area around the aircraft unreadable, even when the aircraft was still below

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By 1957 a new network combining these systems was outlined under the name "Ahead". The system would cover the entire British Isles, like ROTOR and the Type 80s before it. Because the new systems had even longer range than Type 80, the number of stations would be smaller, with the baseline deployment

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With the introduction of these Type 80 Mark III's, the ROTOR plan was obsolete. There was no longer any need to send information to a central plotting room, as the radars could do everything directly from their displays. Many of the underground bunkers, recently completed at great expense, were sold

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and a lash-up antenna. The system more than doubled the effective range for early warning, and when married to a more suitable antenna, provided good detection of bomber-sized aircraft out to 200 miles (320 km). This filled most of the requirements for MEW, but would be available years earlier.

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In the late 1970s, plot extraction equipment was introduced. This took the primary and associated secondary radar outputs, combined and processed them before sending them over telephone lines to the L1. The RPEARDS (Radar Plot Extraction And Remote Display Equipment) was a hard-wired computer that

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In the original design, processed radar signals were returned from the radar station to L1 and LATCC via microwave links. In the 1960s and 1970s this consisted of processed, but by today's standard raw, video and turning information (i.e. the angle of azimuth of the radar aerial). Received signals

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Linesman, as originally conceived, never became operational. It went operational in the early 1970s but only in producing and disseminating the overall Recognised Air Picture, the General Situation Display and the Higher Formation display until 1984. The interception side was only ever used in the

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The three Type 85 radars located at Neatishead, Staxton Wold, and Boulmer used the associated high speed PD aerials to make a PD baseline. For this the two aerials (T85 and PD) 100 miles apart had to be in sync to ensure they swept the same area of sky at the same time, sync and turning information

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The secondary radar system SSR750 as part of the joint military civil functionality could interrogate a transponder on board as aircraft for the height. This height, automatically derived from the onboard altimeter, was in the late 1960s and early 1970s shown to the operator on a box mounted above

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SSR750. Each primary radar had an associated secondary radar, at RAF Staxton Wold and RAF Neatishead there was an additional "freestanding" SSR. Secondary Radar information was associated with the primary (search) radar and presented on the same display. This gave operators a range of information

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As with the ROTOR plan, buildings were given "R" designations, including underground bunkers as well as above-ground technical and operations buildings. There was a serious fire in the R3 bunker at RAF Neatishead where it had to move into temporary buildings above ground for some time. In addition,

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Through the 1950s, the RAF had become accustomed to treating the airspace above 40,000 feet (12 km) as their own to use as they saw fit. At that time, the RAF's fighters and bombers were jet powered and flew at altitudes and speeds that the civilian aircraft, mostly propeller-driven, could not

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If this was the case, there was really no purpose to the air defence beyond the most minimal systems needed for identification. By 1957 even the concept of defending the V bombers was abandoned; if there was credible warning of any sort of attack the bombers had to launch immediately because in all

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rendered this concept useless. In this case, a single aircraft escaping interception could cause enormous damage. Estimating the number of bombers that would reach their targets, it appeared any such attack would result in the UK being devastated. In this environment, the only way to protect the UK

287:, led to studies to rapidly re-implement the air defence system. Most influential was the Cherry Report, which outlined a set of equipment upgrades at existing WWII-era radar sites to improve their performance, along with an entirely new communications network to coordinate the response. Adopted as 687:

During various reviews of Linesman and the "Ahead" plan it was decided to incorporate civilian air traffic control, the "Mediator" portion of the plan. Linesman and Mediator were now considered jointly, although this led to escalating costs and the subsequent need to scale down the original plan.

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that produced a series of possible locations and plotted them as a series of blips on a unique "theta-phi" display. The operators manually adjusted gains in order to reduce the number of blips, and then sent that information to a remote display where it could be combined with normal data from the

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With the changes brought about by the White Paper, there appeared to be no need for Plan Ahead. However, air planners soon pointed out a critical problem. If the Soviets equipped an aircraft with a powerful carcinotron, they could fly it well off the shore and jam the relatively limited frequency

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milliseconds, then the signal from the carcinotron would mix with the radar's own and cause false signals to appear on the display. The carcinotron's signal was strong enough that it would overwhelm the radar's own signal, filling the radar display with noise and rendering the aircraft invisible.

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A series of follow-up studies by NATS all agreed with Zuckerman, pointing out that a military network would need complete information on civilian flights anyway in order to filter out contacts that were scheduled jetliner traffic. There appeared to be no reason not to merge the networks, and the

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This solution only worked if the carcinotron was forced to spread its signal over a wide bandwidth, and would not work if it could concentrate its signal into a smaller number of frequencies. To ensure this, the radar's signals had to be randomly spread across a wide bandwidth. This could not be

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a radar was a time-consuming process that required an operator to listen for enemy radars on a receiver, isolate signals from potentially threatening radars, and then set up a transmitter on that frequency. This was effective against radars using magnetrons, which cannot change their operational

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The core system principle was to take the input from all sensors and enable 'The Hub Concept' where the system resources were reorganized to provide an air data processing system. This produced an RAP, (Recognised Air Picture) whereby all aircraft and air movements could identified and tracked

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seemed like a useless gesture if an attack was underway, given that there was no situation where these weapons would seriously change the outcome of the war. By 1956, all pretext of general defence was dropped and the RAF adopted the policy that the only worthwhile mission was early warning and

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Whilst Mediator proceeded relatively smoothly, construction of Linesman was greatly delayed and it was not fully operational until March 1974. By that time the strategic threat had changed dramatically, and air strikes on the UK once again became a possibility. Linesman's single centralized L1

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the radar horizon. In one test, any aircraft 20 miles (32 km) to either side of the jammer was invisible, meaning a single powerful jammer could hide an entire formation of aircraft. As the jammer aircraft approached the radar station, the signal would be picked up in the radar antenna's

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in the single storey building, the signal passing through a rotating joint in the rotating cabin before being fed to the hornstacks on the aerial. The aerial was designed as two 60 foot by 21 foot elliptical parabolic antennas placed back-to-back, one acting as the radar, and the other as an

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500 computers were added to this as the Recognised Air Picture Dissemination System (RAPIDS) which also extended the RAP to 1900 by 1900 nautical miles. Long-range early warning data was also fed through data links to and from NATO and French radar sites. Other parts of the system were never

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One was to simply overpower the carcinotron; although it could produce about a kilowatt of output in total, it would have to spread that signal across all the frequencies being used by the various radars. This meant the amount of energy in any one frequency was limited, estimated to be about

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In contrast, the carcinotron could tune so rapidly that one could simply sweep its output through the bandwidth of any potential enemy broadcasts. As long as this was done quickly enough that every radar would see the jamming signal during the flight time of its pulses, on the order of a few

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A third system was later added to the network, the RX12874 "Winkle" passive jamming-detection system or PD system. PD consisted of a series of high-speed rotating antennas mounted on R15 buildings separated by many miles, combined with similar signals captured from a Type 85 radar.

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The HF200 provided another means of finding the height of a target. This radar, rather than continuously rotating, nodded on a bearing selected by the operator. The bearing derived from the main primary radar would enable a reading of the height to be sent back to the operator.

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Prior to this period, the air defence mission in the UK was based on a damage-limitation model which aimed to reduce the amount of damage on the UK while inflicting losses on the enemy that would make follow-up attacks impossible. This sort of concept is best illustrated by the

853:) and the HF200 Height Finders. As Linesman progressed additional systems were introduced to aid ECCM capability and communications. Each primary radar had an associated secondary radar (IFF), SSR 750, with the smaller secondary radar mounted on the main primary radar aerial. 400:

frequency. Against other types of transmitters, the operator on the ground would notice the jamming and change their frequency, starting the jamming process over again. If several radars could see the aircraft, keeping the jammers properly tuned could be an impossible task.

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This image shows the effect of four carcinotron-carrying aircraft on a typical 1950s radar. The aircraft are located at roughly the 4 and 5:30 locations. The display is filled with noise any time the antenna's main lobe or sidelobes pass the jammer, rendering the aircraft

178:. This radar changed its frequency with every pulse, making it impossible for carcinotron operators to know what frequency to jam. The RAF initially proposed an extensive network similar to the Type 80s, known as the "1958 Plan". This was abandoned in the aftermath of the 548:, and their rapid expansion in the late 1950s, had led to a number of close calls between civilian and military traffic. This would only get worse over time. Some sort of system would be needed to cover the high-altitude traffic across the entire UK, and this led to the 647:

Linesman was a comprehensive upgrade of the UK air defence system; along with work on the signalling and communications issues, upgrades to the existing radars were also planned. The existing Type 80 radars used in the MRS network were powerful but relatively easy to

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The original central computer system for Linesman consisted of 21 Plessey XL4 and XL6 computers, integrated as the Radar Data Processing System (RDPS); unusually for the time, they were made using germanium rather than silicon semiconductors at the insistence of the

1078:, where the detection and interception of Russian bombers was a weekly, if not daily, event, Linesman enabled the protection and policing of UK air space. IUKADGE and subsequent developments have all built on the legacy of these systems, systems which stem from the 769:

The concept of two main data processing hubs, the L1 and L2, also divided the UK into two areas: the Northern Track Production Area (NTPA) and the Southern Track Production Area (STPA). The L1 primarily looked after the STPA with inputs from four main sites –

190:, and argued the system should be cancelled. In late 1958, a much smaller system with only three main radars and a single control centre became "Plan Ahead", with its primary purpose being to provide air cover and anti-jamming support for a new anti-missile 201:(ATC). Given enemy aircraft might hide among civilian ones, it was seen that combining data from Plan Ahead and the ATC system would have many advantages. Plan Ahead became Linesman and the ATC system Mediator. The centres would share locations in 790:, Ventnor, Clee Hill, Burington, London 1 and London 2. It was understood from the start that the L1 site, above ground and made largely of glass, was subject to air attack; as the second "L2" site originally planned to be built underground at 969:

There were three height finding facilities within the Linesman system. One was built into the Type 85 radar, the second was a stand-alone system using the HF200 radar and the third was based on the SSR interrogating the aircraft's systems.

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band of the BMEWS. This would obscure a missile attack, and the V bombers would be forced to launch until the nature of the threat was determined. If the Soviets repeated this trick, the bomber force and its crews would be quickly worn out.

571:, to consider it. Zuckerman stated there was no way to significantly reduce the estimated cost of the system and still have a military use. However, he suggested one solution would be to use it as the basis for a shared military/civilian 435:

by two stations by drawing the measured angles on a shared map. But if there is more than one jammer, each station will measure several angles and it is not easy to tell which of the measured crossing points contains the jammer aircraft.

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himself. He desired to move the UK's own force to missiles as well, at which point the network would be superfluous. Eventually, the plan was approved only if all other air defence radars were cancelled, and accordingly, work on the

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was never carried out, elements of the air defence system were devolved out to use the standby capabilities of the radar sites, namely the Standby Local Early Warning and Control (SLEWC) systems at RAF Neatishead and RAF Boulmer.

468:, where the RAF was able to cause enough damage on the German bomber force that daylight raids had to be abandoned. Even in the post-war era with early nuclear bombs, this basic concept was still the prevailing strategic concept. 954:

that far exceeded the traditional, 'range and direction". The secondary radar was a dual military and civil system that worked by interrogating a transponder on board the aircraft, receiving and translating a coded reply.

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Whilst much of the evidence of Linesman systems and their associated above-ground installations has gone, it is still possible to get a feeling for what operating and working at the height of the Cold War was like at the

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sites was progressively turned off, a process that rapidly accelerated with the end of the war in 1945. At the time, it was believed it would be at least another ten years before there would be another major war, so the

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system. In practice the original IFF system was never installed, and instead more modern systems with much smaller antennas were installed on the "front" dish, either below the feed horn, or on top of the main antenna.

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short-term defence of the V bomber bases while they launched, the "protection of the deterrent" mission. This led to a smaller network of only three stations covering the Midlands area, under the new name "Plan Ahead".

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having only five stations. A number of Type 80s would be retained in the new network purely for early warning, in locations were interceptions would not be taking place and the anti-jamming performance was not needed.

333:. But even as these began to be installed, further upgrades to the design pushed the detection range out even further and greatly increased its accuracy. This allowed a single radar to both detect the enemy out to the 865:

AMES Type 84 was a primary "L" band radar. The main transmitting equipment was contained in a building over which the aerial was mounted; this building was given the type designation "R17". The transmitter was a

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The RDPS was working operationally until 1984 when it was scrapped. But the Ahead plan and the Linesman system were one of the earliest visions of using computers for distributive processing in both local and

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Such a complex system required that Operators be fully trained. To this end L1 had a large, digital radar simulator that was capable of generating all the radar inputs of the live system. It was ordered from

159:, replaced all of the ROTOR radars and command centres with a series of nine Master Control Radars and a number of associated secondary radars. While these installations were in progress in the early 1950s, 412:, until the entire display was filled with noise and nothing could be tracked anywhere. It appeared that the decade-long effort to provide radar coverage for the UK was being rendered useless at a stroke. 298:

ROTOR planned for a staged deployment in several phases. The first re-used existing radars and control methods and was to be operational by 1952. The second would replace the Chain Home radars with a new

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As well as the frequency agility and sheer power the Type 85 had multiple receivers enabling the return signals to be detected through the heaviest jamming, this included "dicky fix" receivers to combat

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jamming. Post reception processing, including double integration loops enabling the comparison and discarding of spurious returns enhanced the ECCM capability still further. Whilst not having the

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scenarios missiles would be landing shortly. The key requirement was not air defence, but rapid warning of a missile attack. In October 1957 the UK approached the US about deploying a station of the

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system using multiple Master Radar Stations (MRS) with a single site designated "L1" (Linesman 1). L1 would be able to direct all of the air command using a complete air picture of the UK.

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environment. To augment the existing Type 80 a new Type 84 radar had already been proposed. Linesman proposed that three new radars were developed, two primary long-range search radars;

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During this same period, civilian air traffic was increasing dramatically and led to the 1962 formation of the National Air Traffic Control Services organization to handle national-scale

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Type 85. The idea was to locate any specialty-equipped jammer aircraft within a larger attack, allowing them to be prioritized for attack, thereby lowering the ECM load on other radars.

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System. An air defence system that enables the quick and accurate deployment of assets to intercept a threat conserves resources and targets them to where they are of the most use.

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By 1954 there were serious concerns being expressed about the usefulness of air defences. If the goal was to deter an attack, all that was required was enough warning to ensure the

303:(MEW) set beginning around 1957. More stations would be added and the communications systems updated over time, with the final network being fully implemented by the late 1950s. 737:

commissioned, including three more computers that would have integrated the processing of filed civilian flight plans, and data links that would have been used to integrate the

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Another possibility was to use the carcinotron's own signal as the tracking source. If a single jammer is sending out a signal its location can be determined through simple

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within the UK air space. Intercepts etc. were undertaken at other sites using the information feeds from L1. It continued in operation until the late 1970s, early 1980s.

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The Type 85 working with the Auto Height Computer Type 12493 enabled an operator to select a target and, by triangulation in the radar's 12 beams, obtain a height.

369: 160: 129: 384:. The carcinotron could generate about a kilowatt of output signal, compared to megawatts for the latest examples of the magnetron and newer examples of the 221:

command centre was vulnerable, and the sea-side radars even more so. Money set aside to improve Linesman was instead directed to building its replacement,

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Because the L2 was never implemented, the L1 had to extend its processing to cover the Northern Area as well but, with no computer data links, inputs for

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the field stations sent data to L1 over microwave links, eventually phone lines, where it was recombined to form a country-wide view of the airspace; a

1137: 1008: 930:(MTI) facility the Type 84 had, the frequency band and processing ensured the Type 85 produced a clear picture even under the most arduous conditions. 883:

The received signals from both the primary and secondary radars were processed at the main technical building for the Linesman site, the R12 building.

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because it had reliability data only on the former type. These computers worked together using random highways that were a very early version of a

1632: 598: 561: 557: 728:. The 21 RDPS computers then worked to assemble the Recognised Air Picture (RAP) which covered an area 1024 by 1024 nautical miles over the 1026: 821:

On the output side, the Recognised Air Picture as the General Situation Display (GSD) was fed out as the Higher Formation Display (HFD) to

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By 1961 any remaining argument was overruled, and on 21 February the Treasury released funding for the newly-christened Linesman/Mediator.

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As the nature of the threat of the carcinotron became clear, the Air Ministry began looking for potential solutions. Two concepts emerged.

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The core to the system were the Type 84 & 85 primary radars. Height finding capability was provided by the Type 85 (one of the first

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Linesman, whilst part of the "Ahead" plan, evolved out of the study into combining radar information carried out in the late 1950s by the

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the R3 at RAF Boulmer was closed down for refurbishment in December 1982 and operations moved to the Boulmer Interim Facility (BIF).

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The Type 85, however, offered an extremely advanced ECCM system enabling the shifting frequencies on the fly, or as it is now known

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simply by changing a single input voltage, something the magnetron could not do and the klystron only within a limited bandwidth.

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as they felt there was little reason to deploy any systems when better ones would be available by the time they would be needed.

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Watching the skies: a history of ground radar for the air defence of the United Kingdom by the Royal Air Force from 1946 to 1975

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that had the capacity of some 1000 words, each of over 60 bits in length, and transmission over the telephone line was at 2400

695:, Norfolk, cost cutting between 1960 and 1962 led to a prototype of the L1 system being set up above-ground in Building 123 at 504: 1604: 1552: 1007:

The signals were combined at one of the radar stations (at the location of the Type 85 forming one end of the baseline) in a

637: 594:. This meant the original triangular layout was now an extended line, but this had little effect on the overall performance. 476:

from destruction was to ensure the attack never occurred, and the only way to do that was to offer a significant deterrent.

291:, the new system split the UK's airspace into six "sectors" controlled from underground bunkers using thousands of miles of 174:

Considering several possible solutions, the RAF selected an experimental radar known as Blue Yeoman, but later known as the

721: 68: 217:. Ultimately all three Mediator sites were built, while only "L1" at West Drayton was ever completed as part of Linesman. 1637: 1607:

at Centre for the History of Science, Technology and Medicine, The University of Manchester; archived on 19 February 2005

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his screen. Later, with the advent of plot extraction it could be displayed alongside the aircraft on the traditional

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The entire ROTOR plan was seriously upset by an experimental radar known as "Green Garlic" that was developed at the

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Even this limited deployment was heavily criticised within the government, not the least of which by Prime Minister

451:, allowing the aircraft to be driven off before it could approach close enough to be effective against Blue Riband. 900: 661: 582:

Only minor changes were made to the military network. One was to move the location of the inland radar, originally

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following the successful development of the world's first digital radar simulator by that company. Based on the

337:, but also had the accuracy needed to direct fighters to the targets and get them within range of the fighters' 57: 1039: 700: 567:

Macmillan remained sceptical of Plan Ahead and asked the Chief Scientific Advisor to the Ministry of Aviation,

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The XL4 computer was a 64 bit machine that worked asynchronously rather than being governed by a master clock

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from the PD equipment and aerial turning synchronisation information were transmitted over the same links.

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network in the United Kingdom between the 1960s and 1984. The military side (Linesman) was replaced by the

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ROTOR was initially adjusted to include these radars starting in 1953, known in production form as the

622: 590:, which was intended to cover the BMEWS location now that it had also moved to its final position at 210: 1616: 1029:

computer it could simulate 6 radar heads with jamming and noise while displaying over 200 aircraft.

927: 492: 269: 179: 982: 703:(London Air Traffic Control Centre) in a building nearby. LATCC used the Linesman data in their 483:

force would successfully launch. Directing fighters to their targets and shooting them down with

82: 35: 1089:, the system is still sound even if the technology has improved many times and the threat since 684:. As the system developed more systems were added to improve the ECM capability of the system. 652:. Upgrades were aimed primarily at offering improved jamming resistance in the event of a noisy 830: 810:

had to be voice-told for manual input into the L1 system. Later the L1 also took an input from

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in 1965. This was carried out by a team led by E.A Johnson, working in H Building at Malvern.

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introduced a way to eliminate this ambiguity. This concept was explored in a system known as "

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and the lessons of the Second World War. During the dangerous and tense period that was the

665: 167:, which could output a radio signal at any desired frequency. This made it a very effective 1051: 8: 1059: 708: 629:(ATE) of Liverpool. The concept was to reduce the complexity of the existing distributed 572: 353: 229: 214: 198: 676:

to jamming the two primary radars operated on different frequency bands, the Type 84 in

495:. This paper explored the changes to the strategic outlook with the introduction of the 826: 738: 725: 440: 187: 1588: 1548: 1504: 1086: 933:

As the transmission and reception of the Type 85 was based on 12 beams it was also a

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network and thus share the costs that would otherwise require two complete networks.

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A spin-off from the Linesman/Mediator work at RSRE Malvern was the invention of the

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in Northern Ireland. To this there were also inputs from six civilian radars at

507:(BMEWS) in the UK in a location that would cover attacks on the V bomber bases. 1132: 1117: 771: 733: 704: 280: 252: 132:(IUKADGE), while the civilian side (Mediator) became the modern public-private 1626: 811: 803: 799: 791: 729: 549: 472: 448: 396: 334: 171:

system, and it appeared to render ground-based radars like Type 80 useless.

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processed, combined and transmitted the signals. Its memory was magnetic

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Decoding SSR signals was carried out at L1 with the decoders supplied by

950: 923: 779: 669: 587: 432: 381: 377: 363: 321:. This combined an experimental low-noise receiver with a new high-power 260: 164: 1071: 807: 556:, who were planning an extensive network of their own based on the new 529: 256: 152: 867: 597:

The other change was to move the southern-sector control centre from

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AEW aircraft also had to be voice-told into the L1 computer system.

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Even this mission was ultimately eliminated with the release of the

24: 1075: 934: 850: 692: 668:", with additional height finding capability being provided by the 545: 480: 385: 1619:– GEC Review, vol 13 no. 3, 1998 pp172–189; archived 19 March 2003 345:

off as these Master Radar Stations came online in the late 1950s.

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result would be a network once again covering the entire UK.

292: 288: 284: 273: 246: 191: 144: 125: 1613:– the radar system and Baddow; the computer described is TAC 1263: 586:, to a new location further north on the eastern shoreline, 1090: 1055: 691:

Whilst the L1 was originally intended to be underground at

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During the initial stages of the project RRE became the

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Improved United Kingdom Air Defence Ground Environment

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A new radar, the 1624: 1617:"Forty Years of Marconi Radar from 1946 to 1986" 1564:"Forty Years of Marconi Radar from 1946 to 1986" 1561: 1305: 1085:Conceived, proven and tested in the heat of the 741:missile's computer systems as well as a link to 625:(RRE) at Malvern with the participation of the 520:bomber bases and extending to cover the BMEWS. 640:(RSRE) and, in 1962, AT&E was merged with 1605:Collection of TAC working papers and reports 1070:Linesman built on Rotor which had built on 251:As the threat of German air attack on the 232:and the Type 85s stood down in the 1990s. 627:Automatic Telephone Manufacturing Company 319:Telecommunications Research Establishment 182:, which saw the threat to be moving from 109:Learn how and when to remove this message 1502: 890: 352: 306: 143:was installing a radar network known as 1601:article on the Linesman/Mediator system 1015: 213:, and Mediator planned a third site in 1625: 1595:"Air traffic control in the seventies" 1562:Simons, Roy; Sutherland, John (1998). 699:in 1963. The Mediator element set up 535: 505:Ballistic Missile Early Warning System 255:faded in 1944, the wartime network of 124:was a dual-purpose civil and military 1633:Military radars of the United Kingdom 1540: 1515:from the original on 29 December 2023 1490: 1478: 1466: 1454: 1442: 1427: 1410: 1398: 1383: 1368: 1356: 1344: 1332: 1317: 1293: 1281: 1269: 1257: 1238: 1226: 1214: 1197: 1185: 1173: 1161: 753:. There were even early concepts of 638:Royal Signals and Radar Establishment 988: 886: 856: 608: 550:National Air Traffic Control Service 368:In 1953 the French electronics firm 279:Various events in 1949, notably the 47:adding citations to reliable sources 18: 458: 225:. UKADGE was further expanded with 13: 940: 295:lines to pass information around. 14: 1649: 1582: 1123:Air Ministry Experimental Station 964: 672:HF 200 height-finder. To improve 616: 1093:has been significantly altered. 23: 1534: 1496: 34:needs additional citations for 544:The introduction of the first 510: 348: 1: 1143: 415: 134:National Air Traffic Services 1509:Allan's Virtual Radio Museum 1306:Simons & Sutherland 1998 1148: 1128:Comprehensive Display System 1106:RAF Air Defence Radar Museum 1032: 840: 339:aircraft interception radars 7: 1611:RX12874 - Passive Detection 1111: 949:used in the system was the 10: 1654: 1638:Air defence radar networks 992: 361: 310: 244: 235: 1065: 623:Royal Radar Establishment 372:introduced a new type of 285:first Soviet nuclear bomb 211:Glasgow Prestwick Airport 1505:"Plessey Exchange Works" 1272:, pp. 158–160, 168. 814:in Cornwall. Data from 764: 707:computers to handle all 493:1957 Defence White Paper 471:The introduction of the 439:The introduction of the 270:research and development 268:turned its attention to 240: 180:1957 Defence White Paper 983:Plan position indicator 928:Moving Target Indicator 831:HMS Warrior (Northwood) 485:surface to air missiles 301:Microwave Early Warning 283:and the testing of the 896: 782:in Northumberland and 714:Recognized Air Picture 532:system ended in 1960. 359: 1164:, pp. 22–23, 35. 1040:control interceptions 894: 380:, later known as the 356: 307:Master Radar Stations 16:British radar network 1541:Gough, Jack (1993). 1296:, pp. 181, 182. 1284:, pp. 170, 171. 1016:Operational training 43:improve this article 1591:at radarpages.co.uk 1347:, pp. 151–152. 1260:, pp. 157–158. 1229:, pp. 115–116. 1200:, pp. 126–127. 1108:at RAF Neatishead. 709:air traffic control 660:'s Type 84 and the 573:air traffic control 536:Air traffic control 215:Preston, Lancashire 199:air traffic control 58:"Linesman/Mediator" 1023:Elliott Automation 959:Elliott Automation 897: 827:RAF Bentley Priory 751:wide area networks 726:local area network 360: 188:ballistic missiles 139:In the 1950s, the 1554:978-0-11-772723-6 1087:Battle of Britain 989:Passive detection 916:frequency agility 887:Primary radar T85 857:Primary radar T84 784:RAF Bishops Court 680:, the Type 85 in 674:system resilience 609:Linesman/Mediator 554:Laurence Sinclair 497:ballistic missile 466:Battle of Britain 122:Linesman/Mediator 119: 118: 111: 93: 1645: 1578: 1568: 1558: 1528: 1527: 1522: 1520: 1500: 1494: 1488: 1482: 1476: 1470: 1464: 1458: 1452: 1446: 1440: 1431: 1425: 1414: 1408: 1402: 1396: 1387: 1381: 1372: 1366: 1360: 1354: 1348: 1342: 1336: 1330: 1321: 1315: 1309: 1303: 1297: 1291: 1285: 1279: 1273: 1267: 1261: 1255: 1242: 1236: 1230: 1224: 1218: 1212: 1201: 1195: 1189: 1183: 1177: 1171: 1165: 1159: 1009:phase correlator 823:RAF High Wycombe 776:RAF Staxton Wold 755:packet switching 525:Harold Macmillan 459:Changing threats 323:cavity magnetron 205:, just north of 114: 107: 103: 100: 94: 92: 51: 27: 19: 1653: 1652: 1648: 1647: 1646: 1644: 1643: 1642: 1623: 1622: 1585: 1566: 1555: 1537: 1532: 1531: 1518: 1516: 1501: 1497: 1489: 1485: 1477: 1473: 1465: 1461: 1453: 1449: 1441: 1434: 1426: 1417: 1409: 1405: 1397: 1390: 1382: 1375: 1367: 1363: 1355: 1351: 1343: 1339: 1331: 1324: 1316: 1312: 1304: 1300: 1292: 1288: 1280: 1276: 1268: 1264: 1256: 1245: 1241:, pp. 154. 1237: 1233: 1225: 1221: 1213: 1204: 1196: 1192: 1184: 1180: 1172: 1168: 1160: 1156: 1151: 1146: 1114: 1068: 1035: 1018: 997: 991: 985:(PPI) display. 967: 947:secondary radar 943: 941:Secondary radar 889: 877:secondary radar 859: 843: 767: 759:routing of data 619: 611: 592:RAF Fylingdales 569:Solly Zuckerman 538: 513: 461: 418: 366: 351: 315: 309: 266:Royal Air Force 249: 243: 238: 163:introduced the 141:Royal Air Force 115: 104: 98: 95: 52: 50: 40: 28: 17: 12: 11: 5: 1651: 1641: 1640: 1635: 1621: 1620: 1614: 1608: 1602: 1592: 1584: 1583:External links 1581: 1580: 1579: 1559: 1553: 1536: 1533: 1530: 1529: 1503:Allan Isaacs. 1495: 1493:, p. 230. 1483: 1481:, p. 145. 1471: 1469:, p. 222. 1459: 1457:, p. 173. 1447: 1445:, p. 275. 1432: 1430:, p. 219. 1415: 1413:, p. 180. 1403: 1401:, p. 188. 1388: 1386:, p. 202. 1373: 1371:, p. 179. 1361: 1359:, p. 167. 1349: 1337: 1335:, p. 152. 1322: 1320:, p. 182. 1310: 1308:, p. 186. 1298: 1286: 1274: 1262: 1243: 1231: 1219: 1217:, p. 116. 1202: 1190: 1178: 1166: 1153: 1152: 1150: 1147: 1145: 1142: 1141: 1140: 1135: 1133:Type 984 radar 1130: 1125: 1120: 1118:Chain Home Low 1113: 1110: 1067: 1064: 1034: 1031: 1017: 1014: 993:Main article: 990: 987: 966: 965:Height finding 963: 942: 939: 888: 885: 858: 855: 842: 839: 778:in Yorkshire, 772:RAF Neatishead 766: 763: 734:Ferranti Argus 705:Marconi Myriad 618: 617:Implementation 615: 610: 607: 537: 534: 512: 509: 460: 457: 417: 414: 362:Main article: 350: 347: 311:Main article: 308: 305: 281:Berlin Airlift 253:United Kingdom 245:Main article: 242: 239: 237: 234: 149:war-era radars 117: 116: 31: 29: 22: 15: 9: 6: 4: 3: 2: 1650: 1639: 1636: 1634: 1631: 1630: 1628: 1618: 1615: 1612: 1609: 1606: 1603: 1600: 1596: 1593: 1590: 1589:Radar Type 85 1587: 1586: 1576: 1572: 1565: 1560: 1556: 1550: 1546: 1545: 1539: 1538: 1526: 1514: 1510: 1506: 1499: 1492: 1487: 1480: 1475: 1468: 1463: 1456: 1451: 1444: 1439: 1437: 1429: 1424: 1422: 1420: 1412: 1407: 1400: 1395: 1393: 1385: 1380: 1378: 1370: 1365: 1358: 1353: 1346: 1341: 1334: 1329: 1327: 1319: 1314: 1307: 1302: 1295: 1290: 1283: 1278: 1271: 1266: 1259: 1254: 1252: 1250: 1248: 1240: 1235: 1228: 1223: 1216: 1211: 1209: 1207: 1199: 1194: 1188:, p. 43. 1187: 1182: 1176:, p. 42. 1175: 1170: 1163: 1158: 1154: 1139: 1136: 1134: 1131: 1129: 1126: 1124: 1121: 1119: 1116: 1115: 1109: 1107: 1101: 1099: 1094: 1092: 1088: 1083: 1081: 1077: 1073: 1063: 1061: 1057: 1053: 1047: 1043: 1041: 1030: 1028: 1024: 1013: 1010: 1005: 1001: 996: 986: 984: 978: 974: 971: 962: 960: 955: 952: 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Three more 731: 730:British Isles 727: 723: 717: 715: 710: 706: 702: 698: 694: 689: 685: 683: 679: 675: 671: 667: 663: 659: 655: 651: 645: 643: 639: 634: 632: 628: 624: 614: 606: 604: 600: 595: 593: 589: 585: 580: 576: 574: 570: 565: 563: 559: 555: 552:(NATS) under 551: 547: 542: 533: 531: 526: 521: 517: 508: 506: 500: 498: 494: 489: 486: 482: 477: 474: 473:hydrogen bomb 469: 467: 456: 452: 450: 449:radar horizon 446: 442: 437: 434: 433:triangulation 429: 425: 421: 413: 411: 405: 401: 398: 393: 391: 387: 383: 379: 375: 371: 365: 355: 346: 342: 340: 336: 335:radar horizon 332: 327: 324: 320: 314: 304: 302: 296: 294: 290: 286: 282: 277: 275: 271: 267: 262: 258: 254: 248: 233: 231: 228: 224: 218: 216: 212: 208: 204: 200: 195: 193: 189: 185: 181: 177: 172: 170: 166: 162: 158: 154: 150: 146: 142: 137: 135: 131: 127: 123: 113: 110: 102: 91: 88: 84: 81: 77: 74: 70: 67: 63: 60: – 59: 55: 54:Find sources: 48: 44: 38: 37: 32:This article 30: 26: 21: 20: 1598: 1574: 1570: 1543: 1535:Bibliography 1524: 1517:. Retrieved 1508: 1498: 1486: 1474: 1462: 1450: 1406: 1364: 1352: 1340: 1313: 1301: 1289: 1277: 1265: 1234: 1222: 1193: 1181: 1169: 1157: 1102: 1095: 1084: 1069: 1048: 1044: 1036: 1019: 1006: 1002: 998: 979: 975: 972: 968: 956: 944: 932: 920: 913: 909:AMES Type 85 898: 882: 860: 848: 844: 835: 820: 797: 774:in Norfolk, 768: 747: 718: 697:West Drayton 690: 686: 646: 635: 620: 612: 603:West Drayton 599:RAF Bawburgh 596: 584:RAF Bramcote 581: 577: 566: 562:Marconi S264 558:Decca DASR-1 543: 539: 522: 518: 514: 501: 490: 478: 470: 462: 453: 438: 430: 426: 422: 419: 406: 402: 395:Previously, 394: 376:-generating 367: 343: 331:AMES Type 80 328: 316: 313:AMES Type 80 297: 278: 250: 219: 203:West Drayton 196: 176:AMES Type 85 173: 157:AMES Type 80 138: 121: 120: 105: 96: 86: 79: 72: 65: 53: 41:Please help 36:verification 33: 1519:29 December 1098:touchscreen 924:carcinotron 780:RAF Boulmer 743:Fylingdales 666:Blue Yeoman 588:RAF Boulmer 511:New mission 382:carcinotron 378:vacuum tube 364:Carcinotron 349:Carcinotron 261:AMES Type 7 165:carcinotron 1627:Categories 1571:GEC Review 1491:Gough 1993 1479:Gough 1993 1467:Gough 1993 1455:Gough 1993 1443:Gough 1993 1428:Gough 1993 1411:Gough 1993 1399:Gough 1993 1384:Gough 1993 1369:Gough 1993 1357:Gough 1993 1345:Gough 1993 1333:Gough 1993 1318:Gough 1993 1294:Gough 1993 1282:Gough 1993 1270:Gough 1993 1258:Gough 1993 1239:Gough 1993 1227:Gough 1993 1215:Gough 1993 1198:Gough 1993 1186:Gough 1993 1174:Gough 1993 1162:Gough 1993 1144:References 1072:Chain Home 1052:core store 1027:Elliot 502 816:Shackleton 808:RAF Buchan 739:Bloodhound 530:Blue Joker 441:correlator 416:Plan Ahead 410:side lobes 358:invisible. 257:Chain Home 153:Chain Home 99:April 2022 69:newspapers 1597:– a 1970 1149:Citations 1033:Operation 868:magnetron 851:3D radars 841:Equipment 792:Prestwick 664:Type 85 " 546:jetliners 390:bandwidth 374:microwave 259:(CH) and 1547:. HMSO. 1513:Archived 1112:See also 1076:Cold War 935:3D radar 693:Bawburgh 682:"S" band 678:"L" band 564:radars. 481:V bomber 386:klystron 230:Martello 207:Heathrow 136:(NATS). 1080:Dowding 995:RX12874 905:Marconi 903:(later 895:Type 85 863:Marconi 716:(RAP). 658:Marconi 642:Plessey 541:touch. 397:jamming 236:History 227:Marconi 194:radar. 184:bombers 169:jamming 83:scholar 1599:Flight 1551: 1066:Legacy 1058:using 951:Cossor 445:Winkle 223:UKADGE 147:using 85: 78: 71: 64: 56: 1567:(PDF) 765:Sites 701:LATCC 670:Decca 631:ROTOR 293:telex 289:ROTOR 274:radar 247:ROTOR 241:ROTOR 192:BMEWS 151:like 145:ROTOR 126:radar 90:JSTOR 76:books 1577:(3). 1549:ISBN 1521:2023 1091:9/11 1060:GMSK 1056:baud 945:The 899:The 861:The 829:and 806:and 757:and 560:and 62:news 901:AEI 873:IFF 788:Ash 722:MOD 662:AEI 654:ECM 650:jam 370:CSF 272:of 186:to 161:CSF 45:by 1629:: 1575:13 1573:. 1569:. 1523:. 1511:. 1507:. 1435:^ 1418:^ 1391:^ 1376:^ 1325:^ 1246:^ 1205:^ 1062:. 1042:. 961:. 907:) 833:. 825:, 802:, 761:. 745:. 644:. 341:. 209:, 1557:. 875:/ 112:) 106:( 101:) 97:( 87:· 80:· 73:· 66:· 39:.

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