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Acoustic Location
Acoustic location is the use of sound to determine the distance and direction of its source or reflector. Location can be done actively or passively, and can take place in gases (such as the atmosphere), liquids (such as water), and in solids (such as in the earth). * ''Active'' acoustic location involves the creation of sound in order to produce an echo, which is then analyzed to determine the location of the object in question. * ''Passive'' acoustic location involves the detection of sound or vibration created by the object being detected, which is then analyzed to determine the location of the object in question. Both of these techniques, when used in water, are known as sonar; passive sonar and active sonar are both widely used. Acoustic mirrors and dishes, when using microphones, are a means of passive acoustic localization, but when using speakers are a means of active localization. Typically, more than one device is used, and the location is then triangulated between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiaircraft Defence Sweden 1940
Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, subsurface ( submarine launched), and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures (e.g. barrage balloons). It may be used to protect naval, ground, and air forces in any location. However, for most countries, the main effort has tended to be homeland defence. NATO refers to airborne air defence as counter-air and naval air defence as anti-aircraft warfare. Missile defence is an extension of air defence, as are initiatives to adapt air defence to the task of intercepting any projectile in flight. In some countries, such as Britain and Germany during the Second World War, the Soviet Union, and modern NATO and the United States, ground-based air defence and air defence aircra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphone Array
A microphone array is any number of microphones operating in tandem. There are many applications: * Systems for extracting voice input from ambient noise (notably telephones, speech recognition systems, hearing aids) * Surround sound and related technologies * Binaural recording * Locating objects by sound: acoustic source localization, e.g., military use to locate the source(s) of artillery fire. Aircraft location and tracking. * High fidelity original recordings * Environmental noise monitoring * Robotic navigation (acoustic SLAM) Typically, an array is made up of omnidirectional microphones, directional microphones, or a mix of omnidirectional and directional microphones distributed about the perimeter of a space, linked to a computer that records and interprets the results into a coherent form. Arrays may also be formed using numbers of very closely spaced microphones. Given a fixed physical relationship in space between the different individual microphone transducer arra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Naval Volunteer Reserve
Royal may refer to: People * Royal (name), a list of people with either the surname or given name * A member of a royal family Places United States * Royal, Arkansas, an unincorporated community * Royal, Illinois, a village * Royal, Iowa, a city * Royal, Missouri, an unincorporated community * Royal, Nebraska, a village * Royal, Franklin County, North Carolina, an unincorporated area * Royal, Utah, a ghost town * Royal, West Virginia, an unincorporated community * Royal Gorge, on the Arkansas River in Colorado * Royal Township (other) Elsewhere * Mount Royal, a hill in Montreal, Canada * Royal Canal, Dublin, Ireland * Royal National Park, New South Wales, Australia Arts, entertainment, and media * ''Royal'' (Jesse Royal album), a 2021 reggae album * ''The Royal'', a British medical drama television series * ''The Royal Magazine'', a monthly British literary magazine published between 1898 and 1939 * ''Royal'' (Indian magazine), a men's lifestyle bimonthly * Royal Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir Alfred Rawlinson, 3rd Baronet
Colonel Sir Alfred "Toby" Rawlinson, 3rd Baronet, (17 January 1867 – 1 June 1934) was an English soldier and intelligence officer, sportsman, pioneer motorist and aviator. Early life Rawlinson was the second son of Major-General Sir Henry Creswicke Rawlinson, 1st Baronet, a soldier, diplomat and expert in Persian antiquities. His mother was Louisa Caroline Harcourt, a daughter of Henry Seymour one of the Tory MPs for Taunton. Two of his uncles, Henry Danby Seymour and Alfred Seymour, were also MPs. His older brother became General Henry Rawlinson, 1st Baron Rawlinson, who masterminded the Battle of Amiens and the Hundred Days Offensive that brought the fighting of the First World War to a close. Rawlinson, known to family and friends as "Toby", was born on 17 January 1867 at the family home in Charles Street, Mayfair, in the West End of London. He was educated at Eton College and the Royal Military College, Sandhurst, after which he was commissioned as a 2nd lieutenan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T3 Sound Locator
T3 or T-3 may refer to: Medicine * T3, in endocrinology, triiodothyronine, a thyroid hormone ** Polar T3 syndrome, characterized by low levels of that hormone in polar explorers * T3 spinal nerve * Third thoracic vertebrae * An electrode site, in the 10–20 EEG system Vehicles and transportation * Bankstown Line, a rail service in Sydney, Australia, numbered T3 * Eastern Airways (IATA code) * Fuji T-3, a Japanese primary military trainer aircraft * T3, a model of the Oslo Metro OS T1000 train * Île-de-France tramway Line 3, in Paris * Tatra T3, a tramcar * Trager-Bierens T-3 Alibi, a glider * T3 transit lane, a type of high-occupancy vehicle lane in Australia * Volkswagen Type 2 (T3), the third generation of the Volkswagen Transporter van * T3 tanker, a ship class * Slingsby T-3A Firefly, a former training aircraft of the United States Air Force * T3 Road (Zambia), a road in Zambia * Heathrow Terminal 3 Entertainment * '' T3: Alliance'', an investigative-public affa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steered-Response Power Phase Transform
Steered-Response Power Phase Transform (SRP-PHAT) is a popular algorithm for acoustic source localization, well known for its robust performance in adverse acoustic environments. The algorithm can be interpreted as a beamforming-based approach that searches for the candidate position that maximizes the output of a steered delay-and-sum beamformer. Algorithm Steered-Response Power Consider a system of M microphones, where each microphone is denoted by a subindex m \in \. The discrete-time output signal from a microphone is s_m (n). The (unweighted) steered-response power (SRP) at a spatial point \mathbf = , y, z can be expressed as P_0(\mathbf) \triangleq \sum_ \left\vert \sum_^ s_m(n-\tau_m(\mathbf)) \right\vert^, where \mathbb denotes the set of integer numbers and \tau_m(\mathbf) would be the time-lag due to the propagation from a source located at \mathbf to the m-th microphone. The (weighted) SRP can be rewritten as P(\mathbf) = \frac \sum_^\sum_^ \int_^ \Phi_(e^)S_ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilateration
Trilateration is the use of distances (or "ranges") for determining the unknown position coordinates of a point of interest, often around Earth (geopositioning). When more than three distances are involved, it may be called multilateration, for emphasis. The distances or ranges might be ordinary Euclidean distances (slant ranges) or spherical distances (scaled central angles), as in '' true-range multilateration''; or biased distances (pseudo-ranges), as in ''pseudo-range multilateration''. Trilateration or multilateration should not be confused with ''triangulation'', which uses angles for positioning; and ''direction finding'', which determines the line of sight direction to a target without determining the radial distance. Terminology Multiple, sometimes overlapping and conflicting terms are employed for similar concepts – e.g., ''multilateration'' without modification has been used for aviation systems employing both true-ranges and pseudo-ranges."Multilateration (MLAT) Conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle
In Euclidean geometry, an angle is the figure formed by two Ray (geometry), rays, called the ''Side (plane geometry), sides'' of the angle, sharing a common endpoint, called the ''vertex (geometry), vertex'' of the angle. Angles formed by two rays lie in the plane (geometry), plane that contains the rays. Angles are also formed by the intersection of two planes. These are called dihedral angles. Two intersecting curves may also define an angle, which is the angle of the rays lying tangent to the respective curves at their point of intersection. ''Angle'' is also used to designate the measurement, measure of an angle or of a Rotation (mathematics), rotation. This measure is the ratio of the length of a arc (geometry), circular arc to its radius. In the case of a geometric angle, the arc is centered at the vertex and delimited by the sides. In the case of a rotation, the arc is centered at the center of the rotation and delimited by any other point and its image by the rotation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a ''geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geometries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonometry
Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. The Greeks focused on the calculation of chords, while mathematicians in India created the earliest-known tables of values for trigonometric ratios (also called trigonometric functions) such as sine. Throughout history, trigonometry has been applied in areas such as geodesy, surveying, celestial mechanics, and navigation. Trigonometry is known for its many identities. These trigonometric identities are commonly used for rewriting trigonometrical expressions with the aim to simplify an expression, to find a more useful form of an expression, or to solve an equation. History Sumerian astronomers studied angle measure, using a division of circles into 360 degrees. They, and later the Babylonians, studied the ratios of the sides of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interaural Time Difference
The interaural time difference (or ITD) when concerning humans or animals, is the difference in arrival time of a sound between two ears. It is important in the localization of sounds, as it provides a cue to the direction or angle of the sound source from the head. If a signal arrives at the head from one side, the signal has further to travel to reach the far ear than the near ear. This pathlength difference results in a time difference between the sound's arrivals at the ears, which is detected and aids the process of identifying the direction of sound source. When a signal is produced in the horizontal plane, its angle in relation to the head is referred to as its azimuth, with 0 degrees (0°) azimuth being directly in front of the listener, 90° to the right, and 180° being directly behind. Different methods for measuring ITDs *For an abrupt stimulus such as a click, onset ITDs are measured. An onset ITD is the time difference between the onset of the signal reaching two ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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