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Conical Scanning
Conical scanning is a system used in early radar units to improve their accuracy, as well as making it easier to steer the antenna properly to point at a target. Conical scanning is similar in concept to the earlier lobe switching concept used on some of the earliest radars, and many examples of lobe switching sets were modified in the field to conical scanning during World War II, notably the German Würzburg radar. It was universal among gun laying radars by the end of WWII. Conical scanning uses the non-linear nature of the radar's antennas, which are most sensitive in a single direction. By rotating the antenna, the signal returned from the target will grow stronger and weaker depending on how close it is pointed to the target. By comparing the angle of the antenna to the signal strength and looking for a peak, the angle of the target can be determined, and by examining the shape of the returned signal over time, that angle can be measured with very high precision, on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conical Scan
In geometry, a cone is a three-dimensional figure that tapers smoothly from a flat base (typically a circle) to a point not contained in the base, called the ''apex'' or '' vertex''. A cone is formed by a set of line segments, half-lines, or lines connecting a common point, the apex, to all of the points on a base. In the case of line segments, the cone does not extend beyond the base, while in the case of half-lines, it extends infinitely far. In the case of lines, the cone extends infinitely far in both directions from the apex, in which case it is sometimes called a ''double cone''. Each of the two halves of a double cone split at the apex is called a ''nappe''. Depending on the author, the base may be restricted to a circle, any one-dimensional quadratic form in the plane, any closed one-dimensional figure, or any of the above plus all the enclosed points. If the enclosed points are included in the base, the cone is a solid object; otherwise it is an open surface, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer 11
''Pioneer 11'' (also known as ''Pioneer G'') is a NASA robotic space probe launched on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, the solar wind, and cosmic rays. It was the first probe to Exploration of Saturn, encounter Saturn, the second to fly through the Asteroid belt#Exploration, asteroid belt, and the second to fly by Jupiter. Later, ''Pioneer 11'' became the List of artificial objects leaving the Solar System, second of five artificial objects to achieve an escape velocity allowing it to Solar System#Farthest regions, leave the Solar System. Due to power constraints and the vast distance to the probe, the last routine contact with the spacecraft was on September 30, 1995, and the last good engineering data was received on November 24, 1995. Mission background History Approved in February 1969, ''Pioneer 11'' and its twin probe, ''Pioneer 10'', were the first to be designed for exploring the outer Solar System. Yielding to multip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Air Force
The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allies of World War I, Allied victory over the Central Powers in 1918, the RAF emerged as the largest air force in the world at the time. Since its formation, the RAF has played History of the Royal Air Force, a significant role in Military history of the United Kingdom, British military history. In particular, during the Second World War, the RAF established Air supremacy, air superiority over Nazi Germany's Luftwaffe during the Battle of Britain, and led the Allied strategic bombing effort. The RAF's mission is to support the objectives of the British Ministry of Defence (United Kingdom), Ministry of Defence (MOD), which are to "provide the capabilities nee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuselage
The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as well, although in some amphibious aircraft the single engine is mounted on a hardpoint, pylon attached to the fuselage, which in turn is used as a floating Hull (watercraft), hull. The fuselage also serves to position the Flight control surfaces, control and Stabilizer (aeronautics), stabilization surfaces in specific relationships to Wing, lifting surfaces, which is required for aircraft stability and maneuverability. Types of structures Truss structure This type of structure is still in use in many lightweight aircraft using welding, welded steel tube trusses. A box truss fuselage structure can also be built out of wood—often covered with plywood. Simple box structures may be rounded by the addition of supported lightweight strin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT Radiation Laboratory
The Radiation Laboratory, commonly called the Rad Lab, was a microwave and radar research laboratory located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. It was first created in October 1940 and operated until 31 December 1945 when its functions were dispersed to industry, other departments within MIT, and in 1951, the newly formed MIT Lincoln Laboratory. The use of microwaves for various radio and radar uses was highly desired before the war, but existing microwave devices like the klystron were far too low powered to be useful. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, organized the Microwave Committee to consider these devices and look for improvements. In early 1940, Winston Churchill organized what became the Tizard Mission to introduce U.S. researchers to several new technologies the UK had been developing. Among these was the cavity magnetron, a leap forward in the creation of microwaves that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCR-584 Radar
The SCR-584 (short for '' Set, Complete, Radio # 584'') was an automatic-tracking microwave radar developed by the MIT Radiation Laboratory during World War II. It was one of the most advanced ground-based radars of its era, and became one of the primary gun laying radars used worldwide well into the 1950s. A trailer-mounted mobile version was the SCR-784. In 1937, America's first fire-control radar, the SCR-268 radar, had proven to be insufficiently accurate due in part to its long wavelength. In 1940, Vannevar Bush, heading the National Defense Research Committee, established the "Microwave Committee" (section D-1) and the "Fire Control" division (D-2) to develop a more advanced radar anti-aircraft system in time to assist the British air-defense effort. 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), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tizard Mission
The Tizard Mission, officially the British Technical and Scientific Mission, was a delegation from the United Kingdom that visited the United States during World War II to share secret research and development (R&D) work that had military applications. It received its popular name from the programme's instigator, Henry Tizard, a British scientist and chairman of the Aeronautical Research Committee, which had orchestrated the development of radar. The mission travelled to the U.S. in September 1940 during the Battle of Britain. They conveyed a number of British technical and scientific secrets with the objective of securing U.S. assistance in sustaining the war effort and obtaining the industrial resources to exploit the military potential of these technologies, which Britain itself could not fully use, due to the immediate demands of other war-related production. Referring to one such British secret, a device known as a resonant cavity magnetron, American historian James Phin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCR-268 Radar
The SCR-268 (for ''Signal Corps Radio no. 268'') was the United States Army's first radar system. Introduced in 1940, it was developed to provide accurate aiming information for antiaircraft artillery and was also used for gun laying systems and directing searchlights against aircraft. The radar was widely utilized by both Army and United States Marine Corps, Marine Corps air defense and early warning units during World War II. By the end of World War II the system was already considered out of date, having been replaced by the much smaller and more accurate SCR-584 microwave-based system. Development The Signal Corps (United States Army), Signal Corps had been experimenting with some radar concepts as early as the late 1920s, under the direction of Colonel William R. Blair, director of the Signal Corps Laboratories at Fort Monmouth, New Jersey. While most of the Corps' efforts revolved around infra-red detection systems (a popular idea at the time), as well as a newer genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Army
The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United States Constitution (1789).See alsTitle 10, Subtitle B, Chapter 301, Section 3001 It operates under the authority, direction, and control of the United States secretary of defense. It is one of the six armed forces and one of the eight uniformed services of the United States. The Army is the most senior branch in order of precedence amongst the armed services. It has its roots in the Continental Army, formed on 14 June 1775 to fight against the British for independence during the American Revolutionary War (1775–1783). After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.Library of CongressJournals of the Continental Congress, Volume 27/ref> Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipole Antenna
In radio and telecommunications a dipole antenna or doublet is one of the two simplest and most widely used antenna types, types of antenna; the other is the monopole antenna, monopole. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each far end. A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods. The driving current from the transmitter is applied, or for receiving antennas the output signal to the radio receiver, receiver is taken, between the two halves of the antenna. Each side of the feedline to the transmitter or receiver is connected to one of the conductors. This contrasts with a monopole antenna, which consists of a single rod or conductor with one side of the feedline connected to it, and the other side connected to some type of g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraboloid
In geometry, a paraboloid is a quadric surface that has exactly one axial symmetry, axis of symmetry and no central symmetry, center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry. Every plane section of a paraboloid made by a plane Parallel (geometry)#A line and a plane, parallel to the axis of symmetry is a parabola. The paraboloid is hyperbolic if every other plane section is either a hyperbola, or two crossing lines (in the case of a section by a tangent plane). The paraboloid is elliptic if every other nonempty plane section is either an ellipse, or a single point (in the case of a section by a tangent plane). A paraboloid is either elliptic or hyperbolic. Equivalently, a paraboloid may be defined as a quadric surface that is not a cylinder, and has an implicit surface, implicit equation whose part of degree two may be factored over the complex numbers into two different linear factors. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
