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Positioning System
A positioning system is a system for determining the position of an object in space. One of the most well-known and commonly used positioning systems is the Global Positioning System (GPS). Positioning system technologies exist ranging from worldwide coverage with meter accuracy to workspace coverage with sub-millimeter accuracy. 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) allow specialized radio receivers to determine their 3-D space position, as well as time, with an accuracy of 2–20 metres or tens of nanoseconds. Currently deployed systems use microwave signals that can only be received reliably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Position (geometry)
In geometry, a position or position vector, also known as location vector or radius vector, is a Euclidean vector that represents the position of a point ''P'' in space in relation to an arbitrary reference origin ''O''. Usually denoted x, r, or s, it corresponds to the straight line segment from ''O'' to ''P''. In other words, it is the displacement or 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 Relative position The relative position of a point ''Q'' with respect to point ''P'' is the Euclidean vector resulting from the subtraction of the two absolute position vectors (each with respect to the origin): :\Delta \mathbf=\ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellphone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are known as fea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Six Degrees Of Freedom
Six degrees of freedom (6DOF) refers to the six mechanical degrees of freedom of movement of a rigid body in three-dimensional space. Specifically, the body is free to change position as forward/backward (surge), up/down (heave), left/right (sway) translation in three perpendicular axes, combined with changes in orientation through rotation about three perpendicular axes, often termed yaw (normal axis), pitch (transverse axis), and roll (longitudinal axis). Three degrees of freedom (3DOF), a term often used in the context of virtual reality, typically refers to tracking of rotational motion only: pitch, yaw, and roll. Robotics Serial and parallel manipulator systems are generally designed to position an end-effector with six degrees of freedom, consisting of three in translation and three in orientation. This provides a direct relationship between actuator positions and the configuration of the manipulator defined by its forward and inverse kinematics. Robot arms are d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudolite
Pseudolite is a contraction of the term "pseudo-satellite," used to refer to something that is not a satellite which performs a function commonly in the domain of satellites. Pseudolites are most often small transceivers that are used to create a local, ground-based Global Positioning System (GPS) alternative. The range of each transceiver's signal is dependent on the power available to the unit. Being able to deploy one's own positioning system, independent of the GPS, can be useful in situations where the normal GPS signals are either blocked/jammed (military conflicts), or simply not available (exploration of other planets). Pseudolites are normally used to augment the GPS by improving dilution of precision (DOP). Or pseudolites are also used to implement GPS-like indoor location systems, where pseudolites are acting as GPS satellites. Pseudolites use cheap voltage controlled oscillator, so pseudolite based location system shall provide a methodology to compensate clock diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 utili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 notably absent. Seven years later, during a period when the character was undergoing a resurgence in popularity, plans for a Winnie the Pooh attraction were approved at Walt Disney World. Planners used an existing structure, that of the Fantasyland attraction Mr. Toad's Wild Ride. The next version of the attraction, considerably 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 spac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Masts And Towers
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. In the case of a mast radiator or radiating tower, the whole mast or tower is itself 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 guys. Broadcast engineers in the UK use the same terminology. A mast is a ground-based or rooftop structure that supports antennas at a height where they can satisfactorily send or receive radio waves. Typical masts are of steel lattice or tubular steel construction. Masts themselves play no part in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urban Canyon
An urban canyon (also known as a street 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, and Hong Kong's Kowloon and 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. The most important geometrical detail about a street canyon is the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, Bluet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decca Navigator System
The Decca Navigator System was a hyperbolic navigation, hyperbolic radio navigation system which 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 of two 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 invented in the U.S., but development was carried out 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 li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. In the case of a mast radiator or radiating tower, the whole mast or tower is itself 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 guys. Broadcast engineers in the UK use the same terminology. A mast is a ground-based or rooftop structure that supports antennas at a height where they can satisfactorily send or receive radio waves. Typical masts are of steel lattice or tubular steel construction. Masts themselves play no part in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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