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GPS Receivers
A satellite navigation (satnav) device or GPS device is a device that uses satellites of the Global Positioning System (GPS) or similar global navigation satellite systems (GNSS). A satnav device can determine the user's geographic coordinates and may display the geographical position on a map and offer routing directions (as in turn-by-turn navigation). , four GNSS systems are operational: the original United States' GPS, the European Union's Galileo, Russia's GLONASS, and China's BeiDou Navigation Satellite System. The Indian Regional Navigation Satellite System (IRNSS) will follow and Japan's Quasi-Zenith Satellite System ( QZSS) scheduled for 2023 will augment the accuracy of a number of GNSS. A satellite navigation device can retrieve location and time information from one or more GNSS systems in all weather conditions, anywhere on or near the Earth's surface. Satnav reception requires an unobstructed line of sight to four or more GNSS satellites, and is subject to poo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garmin Nüvi 200
Garmin Ltd. is an American multinational technology company based in Olathe, Kansas. The company designs, develops, manufactures, markets, and distributes GPS-enabled products and other navigation, communication, sensor-based, and information products to the automotive, aviation, marine, outdoors, and sport markets. Garmin was founded in 1989 by Gary Burrell and Min Kao in Lenexa, Kansas. In 1996, the company established corporate headquarters in Olathe, Kansas. Since 2010, the company has been legally incorporated in Schaffhausen, Switzerland, with principal subsidiaries located in the United States, Taiwan, and the United Kingdom. As of 2024, the company has nearly 22,000 employees in 34 countries and generated US$6.3 billion in revenue. Garmin was initially associated with personal in-car navigation devices, but now offers several product lines across different markets, with an emphasis on smartwatch technology. In 2022, Garmin smartwatches represented the largest market s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multipath Propagation
In radio communication, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings. When the same signal is received over more than one path, it can create interference and phase shifting of the signal. Destructive interference causes fading; this may cause a radio signal to become too weak in certain areas to be received adequately. For this reason, this effect is also known as multipath interference or multipath distortion. Where the magnitudes of the signals arriving by the various paths have a distribution known as the Rayleigh distribution, this is known as Rayleigh fading. Where one component (often, but not necessarily, a line of sight component) dominates, a Rician distribution provides a more accurate model, and this is k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geodesy
Geodesy or geodetics is the science of measuring and representing the Figure of the Earth, geometry, Gravity of Earth, gravity, and Earth's rotation, spatial orientation of the Earth in Relative change, temporally varying Three-dimensional space, 3D. It is called planetary geodesy when studying other astronomical body, astronomical bodies, such as planets or Natural satellite, circumplanetary systems. Geodynamics, Geodynamical phenomena, including crust (geology), crustal motion, tides, and polar motion, can be studied by designing global and national Geodetic control network, control networks, applying space geodesy and terrestrial geodetic techniques, and relying on Geodetic datum, datums and coordinate systems. Geodetic job titles include geodesist and geodetic surveyor. History Geodesy began in pre-scientific Classical antiquity, antiquity, so the very word geodesy comes from the Ancient Greek word or ''geodaisia'' (literally, "division of Earth"). Early ideas about t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selective Availability
The error analysis for the Global Positioning System is important for understanding how GPS works, and for knowing what magnitude of error should be expected. The GPS makes corrections for receiver clock errors and other effects but there are still residual errors which are not corrected. GPS receiver position is computed based on data received from the satellites. Errors depend on geometric dilution of precision and the sources listed in the table below. Overview User equivalent range errors (UERE) are shown in the table. There is also a numerical error with an estimated value, \ \sigma_ , of about . The standard deviations, \ \sigma_R, for the coarse/acquisition (C/A) and precise codes are also shown in the table. These standard deviations are computed by taking the square root of the sum of the squares of the individual components (i.e., RSS for root sum squares). To get the standard deviation of receiver position estimate, these range errors must be multiplied by the app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronald Reagan
Ronald Wilson Reagan (February 6, 1911 – June 5, 2004) was an American politician and actor who served as the 40th president of the United States from 1981 to 1989. He was a member of the Republican Party (United States), Republican Party and became an important figure in the American conservative movement. Presidency of Ronald Reagan, His presidency is known as the Reagan era. Born in Illinois, Reagan graduated from Eureka College in 1932 and was hired the next year as a sports broadcaster in Iowa. In 1937, he moved to California where he became a well-known film actor. During his acting career, Reagan was president of the Screen Actors Guild twice from 1947 to 1952 and from 1959 to 1960. In the 1950s, he hosted ''General Electric Theater'' and worked as a motivational speaker for General Electric. During the 1964 United States presidential election, 1964 presidential election, Reagan's "A Time for Choosing" speech launched his rise as a leading conservative figure. After b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Korean Air Lines Flight 007
Korean Air Lines Flight 007 (KE007/KAL007)In aviation, two types of Airline codes, airline designators are used. The flight number KAL 007, with the ICAO code for Korean Air Lines, was used by air traffic control. In ticketing, however, IATA codes are used instead, so the flight was referred to as KE007 in the booking systems and on the passengers' tickets. was a scheduled Korean Air Lines flight from New York City to Seoul via Anchorage, Alaska. On September 1, 1983, the flight was shot down by a Soviet Sukhoi Su-15, Sukhoi Su-15TM Flagon-F interceptor aircraft. The Boeing 747-230B airliner was en route from Anchorage to Seoul, but owing to a navigational mistake made by the crew, the airliner drifted from its planned route and flew through Soviet airspace. The Soviet Air Forces treated the unidentified aircraft as an intruding U.S. spy plane, and destroyed it with air-to-air missiles, after firing warning shots. The South Korean airliner eventually crashed into the sea near ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellan Trailblazer XL GPS Handheld Receiver
Ferdinand Magellan ( – 27 April 1521) was a Portuguese explorer best known for having planned and led the 1519–22 Spanish expedition to the East Indies. During this expedition, he also discovered the Strait of Magellan, allowing his fleet to pass from the Atlantic into the Pacific Ocean and perform the first European navigation to Asia via the Pacific. Magellan was killed in battle in the Philippines and his crew, commanded by the Spanish Juan Sebastián Elcano, completed the return trip to Spain in 1522 achieving the first circumnavigation of Earth in history. Born around 1480 into a family of minor Portuguese nobility, Magellan became a skilled sailor and naval officer in service of the Portuguese Crown in Asia. King Manuel I refused to support Magellan's plan to reach the Moluccas, or Spice Islands, by sailing westwards around the American continent. Magellan then proposed the same plan to King Charles I of Spain, who approved it. In Seville, he married, fathered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transit (satellite)
The Transit system, also known as NAVSAT or NNSS (for ''Navy Navigation Satellite System''), was the first satellite navigation system to be used operationally. The radio navigation system was primarily used by the U.S. Navy to provide accurate location information to its UGM-27 Polaris, Polaris ballistic missile submarines, and it was also used as a navigation system by the Navy's surface ships, as well as for hydrographic survey and geodetic surveying. Transit provided continuous navigation satellite service from 1964, initially for Polaris submarines and later for civilian use as well. In the Project DAMP Program, the missile tracking ship USAS American Mariner also used data from the satellite for precise ship's location information prior to positioning its tracking radars. History The Transit satellite system, sponsored by the Navy and developed jointly by DARPA and the Johns Hopkins Applied Physics Laboratory, under the leadership of Dr. Richard Kershner at Johns Hop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 until the dissolution of the Soviet Union in 1991. The term ''Cold war (term), cold war'' is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and Nuclear arms race, nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, Economic sanctions, embargoes, and sports diplomacy. After the end of World War II in 1945, during which the US and USSR had been allies, the USSR installed satellite state, satellite governments in its occupied territories in Eastern Europe and N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Tower
A cell site, cell phone tower, cell base tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjacent cells, in a cellular network. The raised structure typically supports antenna and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing (for CDMA2000/IS-95 or GSM systems), primary and backup electrical power sources, and sheltering. Multiple cellular providers often save money by mounting their antennas on a common shared mast; since separate systems use different frequencies, antennas can be located close together without interfering with each other. Some provider companies operate multiple cellular networks and similarly use colocated base stations for two or more cellular networks, (CDMA2000 or GSM, for example). Cell sites are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Station
Base station (or base radio station, BS) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a " land station in the land mobile service." A base station is called '' node B'' in 3G, '' eNB'' in LTE ( 4G), and '' gNB'' in 5G. The term is used in the context of mobile telephony, wireless computer networking and other wireless communications and in land surveying. In surveying, it is a GPS receiver at a known position, while in wireless communications it is a transceiver connecting a number of other devices to one another and/or to a wider area. In mobile telephony, it provides the connection between mobile phones and the wider telephone network. In a computer network, it is a transceiver acting as a switch for computers in the network, possibly connecting them to a/another local area network and/or the Internet. In traditional wireless communications, it can refer to the hub of a dispatch fleet such as a taxi or delivery fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
