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Terrain-following Radar
Terrain-following radar (TFR) is a military aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level and therefore make detection by enemy radar more difficult. It is sometimes referred to as ''ground hugging'' or ''terrain hugging'' flight. The term ''nap-of-the-earth'' flight may also apply but is more commonly used in relation to low-flying military helicopters, which typically do not use terrain-following radar. TFR systems work by scanning a radar beam vertically in front of the aircraft and comparing the range and angle of the radar reflections to a pre-computed ideal manoeuvring curve. By comparing the distance between the terrain and the ideal curve, the system calculates a manoeuvre that will make the aircraft clear the terrain by a pre-selected distance, often on the order of . Using TFR allows an aircraft to automatically follow terrain at very low levels and high speeds. Terrain-following r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BAC TSR2 Cosford-01
BAC or Bac may refer to: Places * Bac, a village in Montenegro * Baile Átha Cliath, Irish language name for Dublin city. * Bîc River, aka ''Bâc River'', a Moldovan river * Baç Bridge, bridge in Turkey * Barnes County Municipal Airport (ICAO airport code: KBAC; FAA airport code: BAC) Valley City, North Dakota, US; see List of airports in North Dakota Arts and entertainment * Baryshnikov Arts Center, in Manhattan, New York City * '' Batman: Arkham City'', a 2011 video game * Battersea Arts Centre, London, England * Benedicta Arts Center, St. Joseph, Minnesota, USA * Big Apple Chorus, New York based barbershop chorus * Boston Area Crusaders, former name of the Boston Crusaders Drum and Bugle Corps Organizations * BAC-Credomatic, a Central American financial company owned by Grupo Aval Acciones y Valores * Baltimore Aircoil Company, a manufacturer of cooling towers * Bangabandhu Aeronautical Centre * Bank of America, which trades on the NYSE under the stock ticker BAC * Boe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pencil Beam
In optics, a pencil or pencil of rays is a geometric construct used to describe a beam or portion of a beam of electromagnetic radiation or charged particles, typically in the form of a narrow beam ( conical or cylindrical). Antennas which strongly bundle in azimuth and elevation are often described as "pencil-beam" antennas. For example, a phased array antenna can send out a beam that is extremely thin. Such antennas are used for tracking radar, and the process is known as beamforming. In optics, the focusing action of a lens is often described in terms of pencils of rays. In addition to conical and cylindrical pencils, optics deals with astigmatic pencils as well. In electron optics, scanning electron microscopes use narrow pencil beams to achieve a deep depth of field. Ionizing radiation used in radiation therapy, whether photons or charged particles, such as proton therapy and electron therapy machines, is sometimes delivered through the use of pencil beam scanning. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H2S Radar
H2S was the first airborne, ground scanning radar system. It was developed for the Royal Air Force's Bomber Command during World War II to identify targets on the ground for night and all-weather bombing. This allowed attacks outside the range of the various radio navigation aids like Gee or Oboe, which were limited to about . It was also widely used as a general navigation system, allowing landmarks to be identified at long range. In March 1941, experiments with an early airborne interception radar based on the 9.1 cm wavelength, (3 GHz) cavity magnetron revealed that different objects have very different radar signatures; water, open land and built-up areas of cities and towns all produced distinct returns. In January 1942, a new team was set up to combine the magnetron with a new scanning antenna and plan-position indicator display. The prototype's first use in April confirmed that a map of the area below the aircraft could be produced using radar. The first systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Display
A radar display is an electronic device to present radar data to the operator. The radar system transmits pulses or continuous waves of electromagnetic radiation, a small portion of which backscatter off targets (intended or otherwise) and return to the radar system. The receiver converts all received electromagnetic radiation into a continuous electronic analog signal of varying (or oscillating) voltage that can be converted then to a screen display. Modern systems typically use some sort of raster scan display to produce a map-like image. Early in radar development, however, numerous circumstances made such displays difficult to produce. People ultimately developed several different display types. Oscilloscopes Early radar displays used adapted oscilloscopes with various inputs. An oscilloscope generally receives three ''channels'' of varying (or oscillating) voltage as input and displays this information on a cathode ray tube. The oscilloscope amplifies the input voltages a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Antenna guidance can be made entirely automatic, as in the American SCR-584. Potential failure modes and susceptibility to deception jamming led to the replacement of conical scan systems with monopulse radar sets. They are still used by the Deep Space Network for maintaining communications links to space probes. The spin-stabilized Pioneer 10 and Pioneer 11 probes used onboard conical scanning maneuvers to track Earth in its orbit. Concept A typical radar antenna commonly has a beam width of a few degrees. While this is adequate for locating the target in an earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeronautical Systems Center
The Aeronautical Systems Center (ASC) is an inactivated Air Force product center that designed, developed and delivered weapon systems and capabilities for U.S. Air Force, other U.S. military, allied and coalition-partner warfighters. ASC managed 420 Air Force, joint and international aircraft acquisition programs and related projects; executed an annual budget of $19 billion and employed a workforce of more than 11,000 people located at Wright-Patterson Air Force base and 38 other locations worldwide. ASC's portfolio included capabilities in fighter/attack, long-range strike, reconnaissance, mobility, agile combat support, special operations forces, training, unmanned aircraft systems, human systems integration and installation support. ASC was deactivated during a July 20, 2012 ceremony held at Wright-Patterson Air Force Base, Ohio. History Early Aviation The Airplane Engineering Department, precursor of ASC, was first established under the U.S. Army's Aviation Section, U.S. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Altimeter
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is very widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like aircraft, ships, spacecraf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea State
In oceanography, sea state is the general condition of the free surface on a large body of water—with respect to wind waves and swell—at a certain location and moment. A sea state is characterized by statistics, including the wave height, period, and spectrum. The sea state varies with time, as the wind and swell conditions change. The sea state can be assessed either by an experienced observer (like a trained mariner) or by using instruments like weather buoys, wave radar or remote sensing satellites. In the case of buoy measurements, the statistics are determined for a time interval in which the sea state can be considered to be constant. This duration has to be much longer than the individual wave period, but shorter than the period in which the wind and swell conditions can be expected to vary significantly. Typically, records of one hundred to one thousand wave periods are used to determine the wave statistics. The large number of variables involved in creating and des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heads-up Display
A head-up display, or heads-up display, also known as a HUD (), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view information with the head positioned "up" and looking forward, instead of angled down looking at lower instruments. A HUD also has the advantage that the pilot's eyes do not need to refocus to view the outside after looking at the optically nearer instruments. Although they were initially developed for military aviation, HUDs are now used in commercial aircraft, automobiles, and other (mostly professional) applications. Head-up displays were a precursor technology to augmented reality (AR), incorporating a subset of the features needed for the full AR experience, but lacking the necessary registration and tracking between the virtual content and the user's real-world environment. Overview A typical HUD contains three primary components: a ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autopilot
An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator's control of the vehicle, allowing the operator to focus on broader aspects of operations (for example, monitoring the trajectory, weather and on-board systems). When present, an autopilot is often used in conjunction with an autothrottle, a system for controlling the power delivered by the engines. An autopilot system is sometimes colloquially referred to as ''"George"'' (e.g. ''"we'll let George fly for a while"''). The etymology of the nickname is unclear: some claim it is a reference to inventor George De Beeson, who patented an autopilot in the 1930s, while others claim that Royal Air Force pilots coined the term during World War II to symbolize that their aircraft technically belonged to King George VI. First autopilots In th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-force
The gravitational force equivalent, or, more commonly, g-force, is a measurement of the type of force per unit mass – typically acceleration – that causes a perception of weight, with a g-force of 1 g (not gram in mass measurement) equal to the conventional value of gravitational acceleration on Earth, ''g'', of about . Since g-forces indirectly produce weight, any g-force can be described as a "weight per unit mass" (see the synonym specific weight). When the g-force is produced by the surface of one object being pushed by the surface of another object, the reaction force to this push produces an equal and opposite weight for every unit of each object's mass. The types of forces involved are transmitted through objects by interior mechanical stresses. Gravitational acceleration (except certain electromagnetic force influences) is the cause of an object's acceleration in relation to free fall. The g-force experienced by an object is due to the vector sum of all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
