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Mid-Canada Line
The Mid-Canada Line (MCL), also known as the McGill Fence, was a line of radar stations running east–west across the middle of Canada, used to provide early warning of a Soviet bomber attack on North America. It was built to supplement the Pinetree Line, which was located farther south. The majority of Mid-Canada Line stations were used only briefly from the late 1950s to the mid-1960s, as the attack threat changed from bombers to ICBMs. As the MCL was closed down, the early warning role passed almost entirely to the newer and more capable DEW Line farther north. The MCL was based on the bistatic radar principle, using separated transmitters and receivers. An aircraft flying anywhere between the stations would reflect some of the transmitted signal towards the receiver, where it would mix with the signal travelling directly from the transmitter. The mixing of the two signals produces a pattern that is very easy to detect using simple electronics. As the transmitter is not pul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN/FPS-23
The Motorola AN/FPS-23 was a short-range early warning radar deployed on the Distant Early Warning Line (DEW Line). It was used as a "gap filler", looking for aircraft attempting to sneak by the DEW line by flying between the main AN/FPS-19 stations at low altitude. It could detect aircraft flying at 200 feet over land or 50 feet over water. The system was known as Fluttar (flutter radar) during its development at the Lincoln Laboratory, and this name was widely used for the production units as well. It was also sometimes known as "Type F". MCL In the early 1950s, Canada undertook the development of a pioneering radar system as part of the Mid-Canada Line (MCL). This system was based on continuous wave radars that broadcast a signal between separate transmitter and receiver stations. When an aircraft passed through the space between the stations, some of the signal was reflected off the aircraft and back to the receiver. Today, this style of operation is known as a forward sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piasecki H-21
The Piasecki H-21 Workhorse/Shawnee is an American helicopter, the fourth of a line of tandem rotor helicopters designed and built by Piasecki Helicopter (later Boeing Vertol). Commonly called "the flying banana", it was a multi-mission helicopter, using wheels, skis and floats. The H-21 was originally developed by Piasecki as an Arctic rescue helicopter. The H-21 had cold-weather features permitting operation at temperatures as low as and could be routinely maintained in severe cold weather environments. Design and development Piasecki Helicopter designed and successfully sold to the United States Navy a series of tandem rotor helicopters, starting with the HRP-1 of 1944. The HRP-1 was nicknamed the "flying banana" because of the upward angle of the aft fuselage, which ensured that the large rotors could not strike the fuselage in any flight attitude. The name was later applied to other Piasecki helicopters of similar design, including the H-21. In 1949, Piasecki proposed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bennett Lewis
Wilfrid Bennett Lewis, (June 24, 1908 – January 10, 1987) was a Canadian nuclear scientist and administrator, and was centrally involved in the development of the CANDU reactor. Born in Castle Carrock, Cumberland, England, he earned a doctorate in physics at Cavendish Laboratory, University of Cambridge in 1934, and continued his research in nuclear physics there until 1939. From 1939 until 1946, he was with the Air Ministry, becoming Chief Superintendent of the Telecommunications Research Establishment. In 1946, he moved to Canada, to become director of the division of Atomic Energy Research at the National Research Council of Canada in Chalk River, Ontario. From 1952 until 1963, he was Vice President, Research and Development of the Atomic Energy of Canada Limited, and was Senior Vice President, Science from 1963 until 1973. Starting in the mid-1940s, Lewis directed the development and championed the CANDU system, with its natural uranium fuel moderated by he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mattawa, Ontario
Mattawa is a town in northeastern Ontario, Canada on Algonquin Nation land at the confluence of the Mattawa and Ottawa Rivers in Nipissing District. Mattawa means "Meeting of the Waters" in the Algonquin language. The first Europeans to pass through this area were Étienne Brûlé and Samuel de Champlain. History The area was first inhabited by native people who used the Mattawa River as an important transportation corridor for many centuries. In 1610, Étienne BrûléCanadian Heritage Rivers System: Mattawa River fact sheet, Ministry of Natural ResourcesOnline version) and in 1615, Samuel de Champlain were the first Europeans to travel through the Mattawa area.Archeological and Historic Sites Board of Canada For some 200 years thereafter, it was a link in the important water route leading from Montreal west to Lake Superior. Canoes travelling west up the Ottawa turned left at "the Forks" (the mouth of the Mattawa) to enter the "''Petite Rivière''" ("Small River", as compared ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ottawa
Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core of the Ottawa–Gatineau census metropolitan area (CMA) and the National Capital Region (NCR). Ottawa had a city population of 1,017,449 and a metropolitan population of 1,488,307, making it the fourth-largest city and fourth-largest metropolitan area in Canada. Ottawa is the political centre of Canada and headquarters to the federal government. The city houses numerous foreign embassies, key buildings, organizations, and institutions of Canada's government, including the Parliament of Canada, the Supreme Court, the residence of Canada's viceroy, and Office of the Prime Minister. Founded in 1826 as Bytown, and incorporated as Ottawa in 1855, its original boundaries were expanded through numerous annexations and were ultimately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breadboard
A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits. Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are hence reusable. For this reason, breadboards are also popular with students and in technological education. A variety of electronic systems may be prototyped by using breadboards, from small analog and digital circuits to complete central processing units (CPUs). Compared to more permanent circuit connection methods, modern breadboards have high parasitic capacitance, relatively high resistance, and less reliable connections, which are subject to jostle and physical degradation. Signaling is limited to about 10 MHz, and not everything works properly even well below that frequency. History In the early days of radio, amateurs nailed bare copper wires or terminal strips to a wooden board (often literally a bread cutting board) and sold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McGill University
McGill University (french: link=no, Université McGill) is an English-language public research university located in Montreal, Quebec, Canada. Founded in 1821 by royal charter granted by King George IV,Frost, Stanley Brice. ''McGill University, Vol. I. For the Advancement of Learning, 1801–1895.'' McGill-Queen's University Press, 1980. the university bears the name of James McGill, a Scottish merchant whose bequest in 1813 formed the university's precursor, University of McGill College (or simply, McGill College); the name was officially changed to McGill University in 1885. McGill's main campus is on the slope of Mount Royal in downtown Montreal in the borough of Ville-Marie, with a second campus situated in Sainte-Anne-de-Bellevue, west of the main campus on Montreal Island. The university is one of two members of the Association of American Universities located outside the United States, alongside the University of Toronto, and is the only Canadian member of the Glob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (HVAC) or direct current (HVDC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an "interconnection" in North America, directly connects generators delivering AC power with the same rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Pole
A utility pole is a column or post typically made out of wood used to support overhead power lines and various other public utilities, such as electrical cable, fiber optic cable, and related equipment such as transformers and street lights. It can be referred to as a transmission pole, telephone pole, telecommunication pole, power pole, hydro pole, telegraph pole, or telegraph post, depending on its application. A Stobie pole is a multi-purpose pole made of two steel joists held apart by a slab of concrete in the middle, generally found in South Australia. Electrical wires and cables are routed overhead on utility poles as an inexpensive way to keep them insulated from the ground and out of the way of people and vehicles. Utility poles can be made of wood, metal, concrete, or composites like fiberglass. They are used for two different types of power lines: ''sub transmission lines'', which carry higher voltage power between substations, and ''distribution lines'', which distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interceptor Aircraft
An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are capable of being or are employed as both ‘standard’ air superiority fighters and as interceptors are sometimes known as fighter-interceptors. There are two general classes of interceptor: light fighters, designed for high performance over short range; and heavy fighters, which are intended to operate over longer ranges, in contested airspace and adverse meteorological conditions. While the second type was exemplified historically by specialized night fighter and all-weather interceptor designs, the integration of mid-air refueling, satellite navigation, on-board radar and beyond visual range (BVR) missile systems since the 1960s has allowed most frontline fighter designs to fill the roles once reserved for specialised night/all-weathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Equation
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Square Law
In science, an inverse-square law is any scientific law stating that a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space. Radar energy expands during both the signal transmission and the reflected return, so the inverse square for both paths means that the radar will receive energy according to the inverse fourth power of the range. To prevent dilution of energy while propagating a signal, certain methods can be used such as a waveguide, which acts like a canal does for water, or how a gun barrel restricts hot gas expansion to one dimension in order to prevent loss of energy transfer to a bullet. Formula In mathematical notation the inverse square law can be expressed as an intensity (I) varying as a function of distance (d) from some centre. The intensity is pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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