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Blue Joker
Blue Joker was an experimental moored balloon-mounted, airborne early-warning radar project developed by the Royal Radar Establishment (RRE) starting in 1953. The idea was to position the radar high in the air in order to extend its radar horizon and allow it to see low-flying aircraft. Ground reflections were filtered out using a moving target indicator (MTI) system. Two examples were built and tested in the late 1950s, but the project was cancelled in 1960 as part of the Linesman/Mediator efforts. Development Basic concepts During the early 1950s the Royal Air Force was in the midst of deploying its ROTOR radar network based on the AMES Type 80 (Green Garlic) radars. These were powerful S-band radars able to detect high-flying bombers at ranges as great as . However, due to the curvature of the earth, they were subject to the local radar horizon so low-flying aircraft were not visible until they approached much more closely. In the early 1950s, there was some concern that Sovie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is , with an estimated 2020 population of more than 67 million people. The United Kingdom has evolved from a series of annexations, unions and separations of constituent countries over several hundred years. The Treaty of Union between the Kingdom of England (which included Wales, annexed in 1542) and the Kingdom of Scotland in 170 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave Relay
Microwave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300MHz to 300GHz(1 m - 1 mm wavelength) of the electromagnetic spectrum. Microwave signals are normally limited to the line of sight, so long-distance transmission using these signals requires a series of repeaters forming a microwave relay network. It is possible to use microwave signals in over-the-horizon communications using tropospheric scatter, but such systems are expensive and generally used only in specialist roles. Although an experimental microwave telecommunication link across the English Channel was demonstrated in 1931, the development of radar in World War II provided the technology for practical exploitation of microwave communication. During the war, the British Army introduced the Wireless Set No. 10, which used microwave relays to multiplex eight telephone channels over long distances. A link across the English Channel allowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drum (Wales)
Drum () (Welsh language, Welsh: Y Drum = ''the ridge'') is a summit in the Carneddau mountains in Wales, 2 km north-east of Foel-fras. It is 771 m (2,526 ft) high. It is also known as Carnedd Penyborth-Goch. Its eastern slopes are drained by the Afon Tafolog, a tributary of Afon Roe which flows through the village of Rowen before joining the River Conwy.Nuttall, John & Anne (1999). The Mountains of England & Wales - Volume 1: Wales (2nd edition ed.). Milnthorpe, Cumbria: Cicerone. . See also * Blue Joker, an experimental airborne early-warning radar, tested from a site high on the mountain in 1956 References Mountains and hills of Snowdonia Hewitts of Wales Nuttalls Mountains and hills of Conwy County Borough Mountains and hills of Gwynedd Abergwyngregyn Caerhun {{Gwynedd-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datalink
A data link is the means of connecting one location to another for the purpose of transmitting and receiving digital information (data communication). It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver (two pieces of data terminal equipment) and the interconnecting data telecommunication circuit. These are governed by a link protocol enabling digital data to be transferred from a data source to a data sink. Types There are at least three types of basic data-link configurations that can be conceived of and used: * Simplex communications, most commonly meaning all communications in one direction only. * Half-duplex communications, meaning communications in both directions, but not both ways simultaneously. * Duplex communications, communications in both directions simultaneously. Aviation In civil aviation, a data-link system (known as Controller Pilot Data Link Communications) is used to send information between aircraft and air tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene Terephthalate
Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, and thermoforming for manufacturing, and in combination with glass fibre for engineering resins. In 2016, annual production of PET was 56 million tons. The biggest application is in fibres (in excess of 60%), with bottle production accounting for about 30% of global demand. In the context of textile applications, PET is referred to by its common name, polyester, whereas the acronym ''PET'' is generally used in relation to packaging. Polyester makes up about 18% of world polymer production and is the fourth-most-produced polymer after polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC). PET consists of repeating (C10H8O4) units. PET is commonly recycled, and has the digit 1 (♳) as its resin identification code (RIC). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radome
A radome (a portmanteau of radar and dome) is a structural, weatherproof enclosure that protects a radar antenna (radio), antenna. The radome is constructed of material transparent to radio waves. Radomes protect the antenna from weather and conceal antenna electronic equipment from view. They also protect nearby personnel from being accidentally struck by quickly rotating antennas. Radomes can be constructed in several shapes spherical, geodesic dome, geodesic, planar, etc. depending on the particular application, using various construction materials such as fiberglass, polytetrafluoroethylene, polytetrafluoroethylene (PTFE)-coated fabric, and others. When found on fixed-wing aircraft with forward-looking radar, as are commonly used for object or weather detection, the nose cones often additionally serve as radomes. On aircraft used for airborne early warning and control (AEW&C), a rotating radome, often called a "rotodome", is mounted on the top of the fuselage for 360-degr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superheterodyne
A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency. It was long believed to have been invented by US engineer Edwin Armstrong, but after some controversy the earliest patent for the invention is now credited to French radio engineer and radio manufacturer Lucien Lévy. Virtually all modern radio receivers use the superheterodyne principle; except those software-defined radios using ''direct sampling''. History Heterodyne Early Morse code radio broadcasts were produced using an alternator connected to a spark gap. The output signal was at a carrier frequency defined by the physical construction of the gap, modulated by the alternating current signal from the alternator. Since the output frequency of the alternator was generally in the audible range, this produces an audible a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Oscillator
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process, also called heterodyning, produces the sum and difference frequencies from the frequency of the local oscillator and frequency of the input signal. Processing a signal at a fixed frequency gives a radio receiver improved performance. In many receivers, the function of local oscillator and mixer is combined in one stage called a " converter" - this reduces the space, cost, and power consumption by combining both functions into one active device. Applications Local oscillators are used in the superheterodyne receiver, the most common type of radio receiver circuit. They are also used in many other communications circuits such as modems, cable television set top boxes, frequency division multiplexing systems used in telephone trunklines, microwave relay systems, telemetry systems, atomic clocks, radio telescopes, and milita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavity Magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an oscillator, generating a microwave signal from direct current electricity supplied to the vacuum tube. The use of magnetic fields as a means to control the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Code
The Rainbow Codes were a series of code names used to disguise the nature of various British military research projects. They were mainly used by the Ministry of Supply from the end of the Second World War until 1958, when the ministry was broken up and its functions distributed among the forces. The codes were replaced by an alphanumeric code system. History During WWII, British intelligence was able to glean details of new German technologies simply by considering their code names. For instance, when they heard of a new system known as ''Wotan'', Reginald Victor Jones asked around and found that Wotan was a one-eyed god. Based on this, he guessed it was a radio navigation system using a single radio beam. This proved correct, and the Royal Air Force was able to quickly render it useless through jamming. Wishing to avoid making this sort of mistake, Ministry of Supply (MoS) initiated a system that would be entirely random and deliberately unrelated to the program in any way, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metropolitan-Vickers
Metropolitan-Vickers, Metrovick, or Metrovicks, was a British heavy electrical engineering company of the early-to-mid 20th century formerly known as British Westinghouse. Highly diversified, it was particularly well known for its industrial electrical equipment such as generators, steam turbines, switchgear, transformers, electronics and railway traction equipment. Metrovick holds a place in history as the builders of the first commercial transistor computer, the Metrovick 950, and the first British axial-flow jet engine, the Metropolitan-Vickers F.2. Its factory in Trafford Park, Manchester, was for most of the 20th century one of the biggest and most important heavy engineering facilities in Britain and the world. History Metrovick started as a way to separate the existing British Westinghouse Electrical and Manufacturing Company factories from United States control, which had proven to be a hindrance to gaining government contracts during the First World War. In 1917 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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