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Maidenhead Locator
The Maidenhead Locator System (a.k.a. QTH Locator and IARU Locator) is a geocode#Geocode system, geocode system used by amateur radio operators to succinctly describe their geographic coordinate system, geographic coordinates, which replaced the deprecated QRA locator, which was limited to European Contact (amateur radio), contacts. Its purpose is to be concise, accurate, and robust in the face of Interference (communication), interference and other adverse transmission conditions. The ''Maidenhead Locator System'' can describe locations anywhere in the world. Maidenhead locators are also commonly referred to as ''QTH locators'', ''grid locators'' or ''grid squares'', although the "squares" are distorted on any non-equirectangular projection, equirectangular cartographic projection. Use of the terms ''QTH locator'' and ''QRA locator'' was initially discouraged, as it caused confusion with the older QRA locator system. The only abbreviation recommended to indicate a Maidenhead refe ...
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Geocode
A geocode is a code that represents a geographic entity (location or Geographical feature, object). It is a unique identifier of the entity, to distinguish it from others in a finite set of geographic entities. In general the ''geocode'' is a human-readable and short identifier. Typical geocodes (in bold) and entities represented by it: * ''Country code'' and subdivision code. Polygon of the administrative boundaries of a country or a subdivision. The main examples are ISO codes: ISO 3166-1 alpha-2 code (e.g. AF for Afghanistan or BR for Brazil), and its subdivision conventions, such as ISO 3166-2:AF, subdivision codes (e.g. AF-GHO for Ghor province) or ISO 3166-2:BR, subdivision codes (e.g. BR-AM for Amazonas (Brazilian state), Amazonas state). * ''DGG cell ID''. Identifier of a cell of a discrete global grid: a Geohash code (e.g. ~0.023km2 cell 6vd23gq at Brazil's Geographical centre, centroid) or a Open Location Code, Plus Code (e.g. ~0.0002km2 cell 58Q8XXXX+XX with ...
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Longitude
Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are imaginary semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, south-east London on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absol ...
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Maidenhead Grid Over Europe
Maidenhead is a market town in the Royal Borough of Windsor and Maidenhead in the county of Berkshire, England. It lies on the southwestern bank of the River Thames, which at this point forms the border with Buckinghamshire. In the 2021 Census, the Maidenhead built-up area had a population of 67,375. The town is west of Charing Cross, London and east-northeast of Reading. History The antiquary John Leland claimed that the area around Maidenhead's present town centre was a small Roman settlement called Alaunodunum. He stated that it had all but disappeared by the end of the Roman occupation. Although his source is unknown, there is documented and physical evidence of Roman settlement in the town. There are two well known villa sites in the town, one being in the suburb of Cox Green, and the other just west of the town centre on Castle Hill. This villa sat on the route of the Camlet Way which was a Roman road linking Silchester (Calleva Atrebatum) and Colchester (Camulodu ...
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Equator
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumference, halfway between the North Pole, North and South Pole, South poles. The term can also be used for any other celestial body that is roughly spherical. In three-dimensional space, spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its geographical pole, poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane (geometry), plane perpendicular to its axis of rotation and midway between its geographical poles. On and near the equator (on Earth), noontime sunlight appears almost directly o ...
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Projected Coordinate System
A projected coordinate systemalso called a projected coordinate reference system, planar coordinate system, or grid reference systemis a type of spatial reference system that represents locations on Earth using Cartesian coordinates (''x'', ''y'') on a planar surface created by a particular map projection. Each projected coordinate system, such as "Universal Transverse Mercator WGS 84 Zone 26N," is defined by a choice of map projection (with specific parameters), a choice of geodetic datum to bind the coordinate system to real locations on the earth, an origin point, and a choice of unit of measure. Hundreds of projected coordinate systems have been specified for various purposes in various regions. When the first standardized coordinate systems were created during the 20th century, such as the Universal Transverse Mercator, State Plane Coordinate System, and British National Grid, they were commonly called ''grid systems''; the term is still common in some domains such as the ...
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Prime Meridian
A prime meridian is an arbitrarily chosen meridian (geography), meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. On a spheroid, a prime meridian and its anti-meridian (the 180th meridian in a degree (angle), 360°-system) form a great ellipse. This divides the body (e.g. Earth) into hemispheres of Earth, two hemispheres: the Eastern Hemisphere and the Western Hemisphere (for an east-west notational system). For Earth's prime meridian, various conventions have been used or advocated in different regions throughout history. Earth's current international standard prime meridian is the IERS Reference Meridian. It is derived, but differs slightly, from the Prime meridian (Greenwich), Greenwich Meridian, the previous standard. Longitudes for the Earth and Moon are measured from their prime meridian (at 0°) to 180° east and west. For all other Solar System bodies, longitude is measured from 0° (their prime meridian) to 360� ...
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Greenwich
Greenwich ( , , ) is an List of areas of London, area in south-east London, England, within the Ceremonial counties of England, ceremonial county of Greater London, east-south-east of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Prime meridian (Greenwich), Greenwich Meridian (0° longitude) and Greenwich Mean Time. The town became the site of a royal palace, the Palace of Placentia, from the 15th century and was the birthplace of many House of Tudor, Tudors, including Henry VIII of England, Henry VIII and Elizabeth I. The palace fell into disrepair during the English Civil War and was demolished, eventually being replaced by the Greenwich Hospital (London), Royal Naval Hospital for Sailors, designed by Sir Christopher Wren and his assistant Nicholas Hawksmoor. These buildings became the Old Royal Naval College, Royal Naval College in 1873, and they remained a military education establishment until 1998, when they passed into the ...
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Antimeridian
The 180th meridian or antimeridian is the meridian 180° both east and west of the prime meridian in a geographical coordinate system. The longitude at this line can be given as either east or west. On Earth, the prime and 180th meridians form a great ellipse that divides the planet into the Western and Eastern Hemispheres. Locations The antimeridian passes mostly through the open waters of the Pacific Ocean but also runs across land in Russia, Fiji, and Antarctica. An important function of this meridian is its use as the basis for the International Date Line, which snakes around national borders to maintain date consistency within the territories of Russia, the United States, Kiribati, Fiji and New Zealand. Starting at the North Pole of the Earth and heading south to the South Pole, the 180th meridian passes through: The meridian also passes between (but not particularly close to): *through the Aleutian Island chain of US territory *the Gilbert Islands and the Phoeni ...
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North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the North magnetic pole, Magnetic North Pole. The North Pole is by definition the northernmost point on the Earth, lying antipode (geography), antipodally to the South Pole. It defines geodetic latitude 90° North, as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. No time zone has been assigned to the North Pole, so any time can be used as the local time. Along tight latitude circles, counterclockwise is east and clockwise is west. The North Pole is at the center of the Northern Hemisphere. The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about away, though ...
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South Pole
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is the point in the Southern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True South Pole to distinguish from the south magnetic pole. The South Pole is by definition the southernmost point on the Earth, lying antipode (geography), antipodally to the North Pole. It defines geodetic latitude 90° South, as well as the direction of true south. At the South Pole all directions point North; all lines of longitude converge there, so its longitude can be defined as any degree value. No time zone has been assigned to the South Pole, so any time can be used as the local time. Along tight latitude circles, clockwise is east and counterclockwise is west. The South Pole is at the center of the Southern Hemisphere. Situated on the continent of Antarctica, it is the site of the United States Amundsen–Scott South Pole Station, which was established in 19 ...
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Maidenhead Locator Map
Maidenhead is a market town in the Royal Borough of Windsor and Maidenhead in the county of Berkshire, England. It lies on the southwestern bank of the River Thames, which at this point forms the border with Buckinghamshire. In the 2021 Census, the Maidenhead built-up area had a population of 67,375. The town is west of Charing Cross, London and east-northeast of Reading. History The antiquary John Leland claimed that the area around Maidenhead's present town centre was a small Roman settlement called Alaunodunum. He stated that it had all but disappeared by the end of the Roman occupation. Although his source is unknown, there is documented and physical evidence of Roman settlement in the town. There are two well known villa sites in the town, one being in the suburb of Cox Green, and the other just west of the town centre on Castle Hill. This villa sat on the route of the Camlet Way which was a Roman road linking Silchester (Calleva Atrebatum) and Colchester (Camulodu ...
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AMSAT
AMSAT is a name for various amateur radio satellite organizations worldwide. In particular, it often refers to the Radio Amateur Satellite Corporation, headquartered in Washington, D.C. AMSAT organizations design, build, arrange launches for, and then operate (command) satellites carrying amateur radio payloads, including the OSCAR series of satellites. Other informally affiliated national organizations exist, such as AMSAT Germany (AMSAT-DL) and AMSAT Japan (JAMSAT). History AMSAT was founded in 1969 in Washington, D.C. to continue the efforts begun by OSCAR, Project OSCAR. Its first project was to coordinate the launch of Australis-OSCAR 5, OSCAR 5, constructed by students at the University of Melbourne. Some design modifications were needed and were made by AMSAT members, and the satellite was successfully launched on 30 January 1970, on a NASA Delta (rocket family), Thor Delta launch vehicle. AMSAT's next launch was AMSAT-OSCAR 6 (AO-6) on 15 October 1972. AO-6 was AMSAT' ...
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