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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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BAC TSR2 Cosford-01
BAC or Bac may refer to: Arts and entertainment Arts centres and arts councils * Balochistan Arts Council, in Quetta, Pakistan * Baryshnikov Arts Center, in Manhattan, New York City * Battersea Arts Centre, London, England * Beirut Art Center, Lebanon * Belger Arts Center, Kansas City, Missouri, US * Benedicta Arts Center, St. Joseph, Minnesota, US * Berkeley Art Center, California, US * Black Arts Council, US * Brampton Arts Council, Ontario, Canada * Brooklyn Arts Council, New York City, New York, US Other uses in arts and entertainment * André Bac (1905–1989), a French cinematographer * Ferdinand Bac (1859–1952), a German-French cartoonist, artist, and writer * BAC Films, a French film production and distribution company * BAC Inc. * '' Batman: Arkham City'', a 2011 video game * Big Apple Chorus, New York–based barbershop chorus * Big Apple Circus * Boston Area Crusaders, former name of the Boston Crusaders Drum and Bugle Corps * Brixton Artists Collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pencil Beam
In optics, a pencil or pencil of rays, also known as a pencil beam or narrow beam, is a geometric construct (pencil of half-lines) used to describe a Light beam, beam or portion of a beam of electromagnetic radiation or charged subatomic particle, particles, typically in the form of a Cone (geometry), cone or Cylinder (geometry), cylinder. 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 Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of optical instruments, instruments that use or Photodetector, detect it. Optics usually describes t ..., the focus (optics), focusing action of a lens (optics), lens is often described in terms of pencils of ray (optics), ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monopulse Radar
Monopulse radar is a radar system that uses additional encoding of the radio signal to provide accurate directional information. The name refers to its ability to extract range and direction from a single signal pulse. Monopulse radar avoids problems seen in conical scanning radar systems, which can be confused by rapid changes in signal strength. The system also makes jamming more difficult. Most radars designed since the 1960s are monopulse systems. The monopulse method is also used in passive systems, such as electronic support measures and radio astronomy. Monopulse radar systems can be constructed with reflector antennas, lens antennas or array antennas. Historically, monopulse systems have been classified as either phase-comparison monopulse or amplitude monopulse. Modern systems determine the direction from the monopulse ratio, which contain both amplitude and phase information. The monopulse method does not require that the measured signals are pulsed. The altern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H2S Radar
H2S was the first airborne radar system, airborne, Airborne ground surveillance, ground scanning radar system. It was developed for the Royal Air Force's RAF Bomber Command, 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 (navigation), Gee or Oboe (navigation), Oboe, which were limited to about of range from various base stations. 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 aircraft interception radar based on the 9.1 cm wavelength, S band, (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 indic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Display
A radar display is an electronic device that presents 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 graphics, raster scan display to produce a map-like image. Early in radar development, however, numerous circumstances made such displays difficult to produce. People 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 vo ... [...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. 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] |
Aeronautical Systems Center
The Aeronautical Systems Center (ASC) was a U.S. Air Force product center that designed, developed and delivered aviation weapon systems and capabilities. It developed systems for the U.S. Air Force, other U.S. Department of Defense customers, allied, and coalition/partner/client forces. The ASC and its predecessors were located at Wright-Patterson Air Force Base for decades. ASC was established in 1961, and over its lifetime it managed 420 Air Force, joint and international aircraft acquisition programs and related projects; executed an annual budget that reached $19 billion and employed a workforce of more than 11,000 people located at Wright-Patterson AFB 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 20 July 2012 ceremony h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Altimeter
A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground, reflect, and return to the craft. This type of altimeter provides the distance between the antenna and the ground directly below it, in contrast to a barometric altimeter which provides the distance above a defined vertical datum, usually mean sea level. Principle As the name implies, radar (radio detection and ranging) is the underpinning principle of the system. The system transmits radio waves down to the ground and measures the time it takes them to be reflected back up to the aircraft. The altitude above the ground is calculated from the radio waves' travel time and the speed of light. Radar altimeters required a simple system for measuring the time-of-flight that could be displayed u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heads-up Display
A head-up display, or heads-up display, also known as a HUD () or head-up guidance system (HGS), is any see-through display, transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a Aircraft pilot, 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 Accommodation (eye), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autopilot
An autopilot is a system used to control the path of a vehicle 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 Colloquialism, colloquially referred to as ''"George"'' (e.g. ''"we'll let George fly for a while"; "George is flying the plane now".''). The etymology of the nickname is unclear: some claim it is a reference to American inventor George De Beeson (1897–1965), 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 Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-force
The g-force or gravitational force equivalent is a Specific force, mass-specific force (force per unit mass), expressed in Unit of measurement, units of standard gravity (symbol ''g'' or ''g''0, not to be confused with "g", the symbol for grams). It is used for sustained accelerations that cause a perception of weight. For example, an object at rest on Earth's surface is subject to 1 ''g'', equaling the conventional value of gravitational acceleration on Earth, about . More transient acceleration, accompanied with significant jerk (physics), jerk, is called Shock (mechanics), ''shock''. 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 force for every unit of each object's mass. The types of forces involved are transmitted through objects by interior Stress (mechanics), mechanical stresses. Gravitational acceleration is one cause of an object's accelera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
