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Doppler Velocity Sensor
A Doppler velocity sensor (DVS) is a specialized Doppler radar that uses the Doppler effect to measure the three orthogonal velocity components referenced to the aircraft. When aircraft true heading, pitch and roll are provided by other aircraft systems, it can function as a navigation sensor to perform stand-alone dead reckoning navigation calculations as a Doppler Navigation Set (DNS). Doppler navigation systems are independent of surrounding conditions, perform with high accuracy over land and sea anywhere in the world, and are independent of ground-based aids and space-based satellite navigation systems. Operational principles To measure an aircraft three-dimensional velocity, a Doppler radar antenna is caused to radiate a minimum of three non-coplanar microwave electromagnetic beams toward the earth's surface. Some of the energy is backscattered to the radar by the earth surface. With knowledge of the beam angles, three or more beam-Doppler frequencies are combined to gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Radar
A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the frequency of the returned signal. This variation gives direct and highly accurate measurements of the radial component of a target's velocity relative to the radar. Concept Doppler effect The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the difference between the observed frequency and the emitted frequency of a wave for an observer moving relative to the source of the waves. It is commonly heard when a vehicle sounding a siren approaches, passes and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession. This variation of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. Tides va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Instruments
Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with data about the flight situation of that aircraft, such as altitude, airspeed, vertical speed, heading and much more other crucial information in flight. They improve safety by allowing the pilot to fly the aircraft in level flight, and make turns, without a reference outside the aircraft such as the horizon. Visual flight rules (VFR) require an airspeed indicator, an altimeter, and a compass or other suitable magnetic direction indicator. Instrument flight rules (IFR) additionally require a gyroscopic pitch-bank (artificial horizon), direction (directional gyro) and rate of turn indicator, plus a slip-skid indicator, adjustable altimeter, and a clock. Flight into instrument meteorological conditions (IMC) require radio navigation instruments for precise takeoffs and landings. The term is sometimes used loosely as a synonym for cockpit instruments as a whole, in which context it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardo S
Leonardo is a masculine given name, the Italian, Spanish, and Portuguese equivalent of the English, German, and Dutch name, Leonard. People Notable people with the name include: * Leonardo da Vinci (1452–1519), Italian Renaissance scientist, inventor, engineer, sculptor, and painter Artists * Leonardo Schulz Cardoso, Brazilian singer * Emival Eterno da Costa (born 1963), Brazilian singer known as Leonardo * Leonardo de Mango (1843–1930), Italian-born Turkish painter * Leonardo DiCaprio (born 1974), American actor * Leonardo Pieraccioni (born 1965), Italian actor and director Athletes * Leonardo Araújo (born 1969), usually known as Leonardo, Brazilian World Cup-winning footballer, and former sporting director of Paris Saint Germain * Leonardo Fioravanti (born 1997), Italian surfer * Leonardo Lourenço Bastos (born 1975), Brazilian footballer * Leonardo Bittencourt, German footballer * Leonardo Bonucci (born 1987), Italian footballer * Leonardo Candi (born 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BAE Systems
BAE Systems plc (BAE) is a British multinational arms, security, and aerospace company based in London, England. It is the largest defence contractor in Europe, and ranked the seventh-largest in the world based on applicable 2021 revenues. As of 2017, it is the biggest manufacturer in Britain. Its largest operations are in the United Kingdom and United States, where its BAE Systems Inc. subsidiary is one of the six largest suppliers to the US Department of Defense. Other major markets include Australia, Canada, Japan, India, Saudi Arabia, Turkey, Qatar, Oman and Sweden, where Saudi Arabia is regularly among its top three sources of revenue. The company was formed on 30 November 1999 by the £7.7 billion purchase of and merger with Marconi Electronic Systems (MES), the defence electronics and naval shipbuilding subsidiary of the General Electric Company plc (GEC), by British Aerospace, an aircraft, munitions and naval systems manufacturer. BAE is the successor to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CMC Electronics
CMC Electronics Inc. (french: CMC Électronique) is a Canadian avionics manufacturer. The company's main manufacturing facility is located in Montreal, Quebec with additional facilities located in Ottawa, Ontario and Sugar Grove, Illinois. History The company was founded in 1903 as Canadian Wireless Telegraph Company of Canada by Guglielmo Marconi. In 1925, the company was renamed Canadian Marconi Company. In 1948, English Electric purchased the UK based Marconi Company and in 1953 acquired 50.6% of Canadian Marconi Company. In 1968 English Electric was itself purchased by General Electric Company (GEC), which took control of the 50.6% share of CMC. On November 30, 1999 British Aerospace completed its purchase of GEC's Canadian Electronic Systems to form BAE Systems. In December 1999, BAE Systems purchased GEC's 51.6% share of CMC in a separate transaction. In February 2000 the company changed its name to BAE Systems Canada. In April 2001, ONCAP (an investment group com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination. The basic principles are measurements from/to electric beacons, especially * Angular directions, e.g. by bearing, radio phases or interferometry, * Distances, e.g. ranging by measurement of time of flight between one transmitter and multiple receivers or vice versa, * Distance ''differences'' by measurement of times of arrival of signals from one transmitter to multiple receivers or vice versa * Partly also velocity, e.g. by means of radio Doppler shift. Combinations of these measurement principles also are important—e.g., many radars measure range and azimuth of a target. Bearing-measurement systems These systems used some form of directional radio antenna to determine the location of a broadcast station on the ground. Conventional navigation techni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guidance Systems
A guidance system is a virtual or physical device, or a group of devices implementing a controlling the movement of a ship, aircraft, missile, rocket, satellite, or any other moving object. Guidance is the process of calculating the changes in position, velocity, altitude, and/or rotation rates of a moving object required to follow a certain trajectory and/or altitude profile based on information about the object's state of motion. A guidance system is usually part of a Guidance, navigation and control system, whereas navigation refers to the systems necessary to calculate the current position and orientation based on sensor data like those from compasses, GPS receivers, Loran-C, star trackers, inertial measurement units, altimeters, etc. The output of the navigation system, the navigation solution, is an input for the guidance system, among others like the environmental conditions (wind, water, temperature, etc.) and the vehicle's characteristics (i.e. mass, control system avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Modulation
Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and Run-length limited#FM: .280.2C1.29 RLL, computing. In Analog signal, analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. the difference between the frequency of the carrier and its center frequency, has a functional relation to the modulating signal amplitude. Digital data can be encoded and transmitted with a type of frequency modulation known as frequency-shift keying (FSK), in which the instantaneous frequency of the carrier is shifted among a set of frequencies. The frequencies may represent digits, such as '0' and '1'. FSK is widely used in computer modems, such as fax modems, telephone caller ID systems, garage door openers, and other low-frequency transmissions. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dead Reckoning
In navigation, dead reckoning is the process of calculating current position of some moving object by using a previously determined position, or fix, and then incorporating estimates of speed, heading direction, and course over elapsed time. The corresponding term in biology, used to describe the processes by which animals update their estimates of position or heading, is path integration. Dead reckoning is subject to cumulative errors. Advances in navigational aids that give accurate information on position, in particular satellite navigation using the Global Positioning System, have made simple dead reckoning by humans obsolete for most purposes. However, inertial navigation systems, which provide very accurate directional information, use dead reckoning and are very widely applied. Etymology The term "dead reckoning" was not originally used to abbreviate "deduced reckoning," nor is it a misspelling of the term "ded reckoning." The use of "ded" or "deduced reckoning" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous-wave Radar
Continuous-wave radar (CW radar) is a type of radar system where a known stable frequency continuous wave radio energy is transmitted and then received from any reflecting objects. Individual objects can be detected using the Doppler effect, which causes the received signal to have a different frequency from the transmitted signal, allowing it to be detected by filtering out the transmitted frequency. Doppler-analysis of radar returns can allow the filtering out of slow or non-moving objects, thus offering immunity to interference from large stationary objects and slow-moving clutter. This makes it particularly useful for looking for objects against a background reflector, for instance, allowing a high-flying aircraft to look for aircraft flying at low altitude against the background of the surface. Because the very strong reflection off the surface can be filtered out, the much smaller reflection from a target can still be seen. CW radar systems are used at both ends of the range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
