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Local Positioning System
A positioning system is a system for determining the position of an object in space. Positioning system technologies exist ranging from interplanetary coverage with meter accuracy to workspace and laboratory coverage with sub-millimeter accuracy. A major subclass is made of '' geopositioning systems'', used for determining an object's position with respect to Earth, i.e., its geographical position; one of the most well-known and commonly used geopositioning systems is the Global Positioning System (GPS) and similar global navigation satellite systems (GNSS). Coverage Interplanetary systems Interplanetary-radio communication systems not only communicate with spacecraft, but they are also used to determine their position. Radar can track targets near the Earth, but spacecraft in deep space must have a working transponder on board to echo a radio signal back. Orientation information can be obtained using star trackers. Global systems Global navigation satellite systems (GNSS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Position (geometry)
In geometry, a position or position vector, also known as location vector or radius vector, is a Euclidean vector that represents a Point (geometry), point ''P'' in space. Its length represents the distance in relation to an arbitrary reference origin (mathematics), origin ''O'', and its Direction (geometry), direction represents the angular orientation with respect to given reference axes. Usually denoted x, r, or s, it corresponds to the straight line segment from ''O'' to ''P''. In other words, it is the displacement (vector), displacement or translation (geometry), translation that maps the origin to ''P'': :\mathbf=\overrightarrow. The term position vector is used mostly in the fields of differential geometry, mechanics and occasionally vector calculus. Frequently this is used in two-dimensional or three-dimensional space, but can be easily generalized to Euclidean spaces and affine spaces of any dimension.Keller, F. J., Gettys, W. E. et al. (1993), p. 28–29. Relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Line-of-sight Propagation
Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver without obstacles. Electromagnetic transmission includes light emissions traveling in a straight line. The rays or waves may be diffracted, refracted, reflected, or absorbed by the atmosphere and obstructions with material and generally cannot travel over the horizon or behind obstacles. In contrast to line-of-sight propagation, at low frequency (below approximately 3 MHz) due to diffraction, radio waves can travel as ground waves, which follow the contour of the Earth. This enables AM radio stations to transmit beyond the horizon. Additionally, frequencies in the shortwave bands between approximately 1 and 30 MHz, can be refracted back to Earth by the ionosphere, called skywave or "skip" propagation, thus giving radio transmissions in this range a potentially global reach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Locata Corporation
Locata Corporation is a privately held technology company headquartered in Canberra, Australia, with a fully owned subsidiary in Las Vegas, Nevada. Locata has invented a local positioning system that can either replace or augment Global Positioning System (GPS) signals when they are blocked, jammed or unreliable. Government, commercial and other organizations use Locata to determine accurate positioning as a local backup to GPS. History David Small and Nunzio Gambale started work on the initial Locata concepts in 1994 and founded Locata as a company in 1997. As of December 2013, the company has been granted 122 patents around their positioning technology. Products LocataNet A LocataNet is a ground-based local positioning system that provides positioning information which is indistinguishable from GPS to an appropriately configured receiver. The LocataNet achieves this without the satellites, atomic clocks or ground support structure required by traditional GPS satellite-based s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Mystic Manor
Mystic Manor () is a dark ride attraction in the Mystic Point area of Hong Kong Disneyland. Unlike Disneyland's Haunted Mansion attraction and its counterparts in other Disney parks, Mystic Manor has a lighthearted, fantasy-based theme with no references to departed spirits or the afterlife, due to differences in traditional Chinese culture. The attraction does feature several references to the Haunted Mansion, such as a Medusa changing portrait, a conservatory, and the busts that turn to follow visitors as they move. References to other Disney attractions include several figures similar to those from The Enchanted Tiki Room in the Tribal Arts room. History The Manor's exterior design is inspired by the now-demolished Bradbury Mansion that stood at 147 North Hill Street in Los Angeles' Bunker Hill, designed by Samuel Newsom and Joseph Cather Newsom of the firm Newsom and Newsom, who also designed the still-standing Carson Mansion in Eureka, California. The attraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Pooh's Hunny Hunt
Pooh's Hunny Hunt is a unique trackless dark ride located at Tokyo Disneyland. It is based on the 1977 Disney animated film '' The Many Adventures of Winnie the Pooh''. History After the rise in popularity of Walt Disney's film adaptation of Winnie-the-Pooh, Disney Imagineers made plans in the late 1970s for a Winnie the Pooh attraction at Disneyland's soon-to-be renovated Fantasyland. However, in 1983, when the renovated Fantasyland reopened, a Winnie the Pooh attraction was absent. Seven years later, during a period when the franchise was undergoing a resurgence in popularity, plans for a Winnie the Pooh attraction were approved at Walt Disney World. Planners used an existing structure of the Fantasyland attraction Mr. Toad's Wild Ride. The next version of the attraction, different in configuration, was Pooh's Hunny Hunt, which opened in Tokyo Disneyland. Due to a closure of all of the Skyways at Disney Parks across the world, including Tokyo, a space was left where the Fan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Radio Masts And Towers
Radio masts and towers are typically tall structures designed to support antenna (radio), antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest human-made structures. Masts are often named after the broadcasting organizations that originally built them or currently use them. A mast radiator or radiating tower is one in which the metal mast or tower itself is energized and functions as the transmitting antenna. Terminology The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilevered structure, while a Guyed mast, mast is held up by stays or guy-wires. ; A ''mast'': is a guyed mast, a thin structure without the shear strength to stand unsupported, that uses attached guy lines for stability. They may be mounted on the ground or on top of buildings. Typical ''masts'' are of steel latt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Urban Canyon
An urban canyon (also known as a street canyon or skyscraper canyon) is a place where the street is flanked by buildings on both sides creating a canyon-like environment, evolved etymologically from the Canyon of Heroes in Manhattan. Such human-built canyons are made when streets separate dense blocks of structures, especially skyscrapers. Other examples include the Magnificent Mile in Chicago, Los Angeles' Wilshire Boulevard corridor, Toronto's Financial District, Toronto, Financial District, and Hong Kong's Kowloon and Central, Hong Kong, Central districts. Urban canyons affect various local conditions, including temperature, wind, light, air quality, and radio reception, including satellite navigation signals. Geometry and classification Ideally an urban canyon is a relatively narrow street with tall, continuous buildings on both sides of the road. But now the term urban canyon is used more broadly, and the geometrical details of the street canyon are used to categorize them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Indoor Positioning System
An indoor positioning system (IPS) is a network of devices used to locate people or objects where GPS and other satellite technologies lack precision or fail entirely, such as inside multistory buildings, airports, alleys, parking garages, and underground locations. A large variety of techniques and devices are used to provide indoor positioning ranging from reconfigured devices already deployed such as smartphones, WiFi and Bluetooth antennas, digital cameras, and clocks; to purpose built installations with relays and beacons strategically placed throughout a defined space. Lights, radio waves, magnetic fields, acoustic signals, and behavioral analytics are all used in IPS networks. IPS can achieve position accuracy of 2 cm, which is on par with RTK enabled GNSS receivers that can achieve 2 cm accuracy outdoors. IPS use different technologies, including distance measurement to nearby anchor nodes (nodes with known fixed positions, e.g. WiFi / LiFi access points, Bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Decca Navigator System
The Decca Navigator System was a hyperbolic navigation, hyperbolic radio navigation system that allowed ships and aircraft to determine their position by using radio signals from a dedicated system of static radio transmitters. The system used phase comparison between pairs of low frequency signals between 70 and 129 kilohertz, kHz, as opposed to pulse timing systems like Gee (navigation), Gee and LORAN. This made it much easier to design receivers using 1940s electronics, and operation was simplified by giving a direct readout of Decca coordinates without the complexity of a cathode-ray tube and highly skilled operator. The system was developed by Decca Radar, Decca in the UK. It was first deployed by the Royal Navy during World War II for the vital task of clearing the minefields to enable the D-Day landings. The Allied forces needed an accurate system not known to the Germans and thus free of jamming. After the war, it came off the secret list and was commercially deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Broadcast Tower
Radio masts and towers are typically tall structures designed to support antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the tallest human-made structures. Masts are often named after the broadcasting organizations that originally built them or currently use them. A mast radiator or radiating tower is one in which the metal mast or tower itself is energized and functions as the transmitting antenna. Terminology The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilevered structure, while a mast is held up by stays or guy-wires. ; A ''mast'': is a guyed mast, a thin structure without the shear strength to stand unsupported, that uses attached guy lines for stability. They may be mounted on the ground or on top of buildings. Typical ''masts'' are of steel lattice or tubular steel c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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LiFi
Li-Fi (commonly referred to as LiFi) is a wireless communication technology which utilizes light to transmit data and position between devices. The term was first introduced by Harald Haas during a 2011 TEDGlobal talk in Edinburgh. Li-Fi is a light communication system that is capable of transmitting data at high speeds over the visible light, ultraviolet, and infrared spectrums. In terms of its end user, the technology is similar to Wi-Fi – the key technical difference being that Wi-Fi uses radio frequency to induce an electric tension in an antenna to transmit data, whereas Li-Fi uses the modulation of light intensity to transmit data. Li-Fi is able to function in areas otherwise susceptible to electromagnetic interference (e.g. aircraft cabins, hospitals, or military applications). Technology details Li-Fi is a derivative of optical wireless communications (OWC) technology, which uses light from light-emitting diodes (LEDs) as a medium to deliver network, mobile, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Wi-Fi Positioning System
Wi-Fi positioning system (WPS, WiPS or WFPS) is a geolocation system that uses the characteristics of nearby Wi‑Fi access points to discover where a device is located. It is used where satellite navigation such as GPS is inadequate due to various causes including multipath and signal blockage indoors, or where acquiring a satellite fix would take too long. Such systems include assisted GPS, urban positioning services through hotspot databases, and indoor positioning systems. Wi-Fi positioning takes advantage of the rapid growth in the early 21st century of wireless access points in urban areas. The most common technique for positioning using wireless access points is based on a rough proxy for the strength of the received signal ('' received signal strength indicator'', or ''RSSI'') and the method of "fingerprinting".P. Bahl and V. N. Padmanabhan, “RADAR: an in-building RF-based user location and tracking system,” in Proceedings of 19th Annual Joint Conference of the IEEE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |