AMES Type 84
It was first conceived in 1951 during the ROTOR program as a megawatt-powered S-band system that would replace the WWII-era Chain Home radars for early warning.
But an experimental system developed at the Royal Radar Establishment (RRE) offered similar performance and would be available long before the MEW's 1957 target date.
A new concept emerged as an L-band counterpart to the Type 80, adding an advanced moving target indication (MTI) system.
During development, MEW was the primary radar of the Stage 2 ROTOR plans and was intended to hand-off targets to the Blue Envoy long-range missile.
In the early 1950s the threat of nuclear attack by the Soviet Union led the UK to design an extensive radar network known as ROTOR.
[3] In 1951 the Telecommunications Research Establishment (TRE) began experimenting with new low-noise crystal detectors that improved reception by 10 dB, and new cavity magnetrons of roughly 1 MW power.
Combining these together on a lashed-up antenna system from the war-era AMES Type 14 produced a test unit known as "Green Garlic".
[6] An additional desire was to have the system provide height finding as well, which would eliminate the separate radars that would be needed for that role.
[7] MTI is accomplished by comparing an incoming signal from the current radar pulse with the last one sent, and looking for changes in frequency due to the Doppler shift.
[7] This requires the IF to be extremely stable, which makes it difficult to accomplish with a magnetron as these devices output a slightly different signal, in both frequency and phase, with every pulse.
[7] In place of the klystron, Marconi suggested using an existing magnetron that had proven itself in operation on their test rig at Bushy Hill in use since 1956.
[12][13] In 1950, engineers at the French company CSF (now part of Thales Group) introduced the carcinotron, a microwave-producing vacuum tube that could be rapidly tuned across a wide range of frequencies by changing the input voltage.
The Admiralty Signals and Radar Establishment purchased one and fit it to a Handley Page Hastings named Catherine, testing it against the latest Type 80 late that year.
[17] Known as Blue Riband, the system required four antennas arranged in a square running on a turntable built on top of a modified railroad bed.
One was that attacks by enemy bombers could be fended off by surface-to-air missiles, which had already been earmarked as the primary anti-aircraft weapon of the future in the form of Blue Envoy.
The other was that the emergence of the medium range ballistic missile would replace those bombers in the strategic role as early as 1965, at which point any air defense, including Blue Envoy, was useless.
Matters finally came to a head in 1959, when Prime Minister Harold Macmillan delivered an either-or choice; if the Air Ministry remained adamant in deploying Plan Ahead, they could but only at the price of ending all other air-defense projects.
The decision was made to use the antenna being developed for the Blue Yeoman, a 60 by 21.75 feet (18.29 by 6.63 m) solid-surface design with no effective bandwidth limitation.
This would allow a single unit to produce maps of target echos as well as highly accurate positions of the friendly interceptors.
Given this, the base arrangement was changed to move the inland site to the coast at RAF Bramcote, which would reduce the coverage over the Midlands, but improve the system's early warning capabilities over the North Sea.
The Type 84 at Saxa Vord was later dropped, while the test installation at Bawdsey was earmarked for RAF Bishops Court in Northern Ireland, closing the "back door" approach, and the Buchan example moved to Cyprus.
[28] Concurrently, other groups were studying whether the military early warning and tracking needs could be combined with civilian air traffic control systems.
This led to calls for improved low-level performance, which was delivered by redesigning the feed network for the second Type 84 that was being installed at Neatishead,[31] which entered service in October 1963.
[37] The same was not true for the data handling portion of the Linesman system, which faced repeated delays and only entered minimal operation on 18 December 1973.
Fighter Command repeatedly protested, noting that the entire air defence network might be taken out by an explosive truck on the road outside the building or jamming of the microwave links that fed it.
Additionally, new weapons like the TOW missile fired from attack helicopters appeared to offer an all-conventional method of defeating the Pact.
[41] This was especially true in light of newer long-range Soviet aircraft that could approach the UK at low level and thereby avoid detection altogether.
They proposed using modern commercial computers in place of the specialized systems of Linesman, adding complete digitization of all signals from all radars in the network, upgrading links to their counterparts in NADGE, which were at that time forwarded over voice lines, and devolving command to new hardened CRC centers, remote from the radar sites.
[43] UKADGE found itself in the same situation as Linesman before it; the lengthy delays, cost overruns and obsolescence led to calls for its replacement before it was operational.
A major goal of IUKADGE was to replace the Linesman radars with mobile units that could be stored off-site in secure locations and then brought online quickly after an attack.
