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    What is a geographical coordinate?

    How do you find latitude and longitude address?

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  2. Geographic coordinate system - Wikipedia

    A geographic coordinate system is a coordinate system associated with positions on Earth. A GCS can give positions: as spherical coordinate system using latitude, longitude, and elevation; as map coordinates projected onto the plane, possibly including elevation; as earth-centered, earth-fixed Cartesian coordinates in 3-space; as a set of numbers, letters or symbols forming a geocode. In geodetic coordinates and map coordinates, the coordinate tuple is decomposed such that one of the numbers rep

    • History

      The invention of a geographic coordinate system is generally...

    • Geodetic datum

      In order to be unambiguous about the direction of "vertical"...

  3. Geographic coordinate system - Simple English Wikipedia, the ...

    A geographical coordinate system is a coordinate system. This means that every place can be specified by a set of three numbers, called coordinates. A full circle can be divided into 360 degrees (or 360°); this was first done by the Babylonians; Ancient Greeks, like Ptolemy later extended the theory. Today, degrees are divided further.

  4. Coordinate system - Wikipedia

    In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space. The order of the coordinates is significant, and they are sometimes identified by their position in an ordered tuple and sometimes by a letter, as in "the x-coordinate". The coordinates are taken to be real numbers in elementary mathematics, but may be complex numbers or elements of a more a

  5. Category:Geographic coordinate systems - Wikipedia

    From Wikipedia, the free encyclopedia Wikimedia Commons has media related to Geographic coordinate system. For more information, see Geographic coordinate system.

  6. Geographic coordinate system - WIKI 2. Wikipedia Republished
    • History
    • Geographic Latitude and Longitude
    • Measuring Height Using Datums
    • Map Projection
    • Cartesian Coordinates
    • Expressing Latitude and Longitude as Linear Units
    • Geostationary Coordinates
    • on Other Celestial Bodies
    • See Also
    • References

    The in­ven­tion of a ge­o­graphic co­or­di­nate sys­tem is gen­er­ally cred­ited to Er­atos­thenes of Cyrene, who com­posed his now-lost Ge­og­ra­phy at the Li­brary of Alexan­dria in the 3rd cen­tury BC. A cen­tury later, Hip­parchus of Nicaea im­proved on this sys­tem by de­ter­min­ing lat­i­tude from stel­lar mea­sure­ments rather than solar al­ti­tude and de­ter­min­ing lon­gi­tude by tim­ings of lunar eclipses, rather than dead reck­on­ing. In the 1st or 2nd cen­tury, Mar­i­nus of Tyre com­piled an ex­ten­sive gazetteer and math­e­mat­i­cally-plot­ted world map using co­or­di­nates mea­sured east from a prime merid­ian at the west­ern­most known land, des­ig­nated the For­tu­nate Isles, off the coast of west­ern Africa around the Ca­nary or Cape Verde Is­lands, and mea­sured north or south of the is­land of Rhodes off Asia Minor. Ptolemy cred­ited him with the full adop­tion of lon­gi­tude and lat­i­tude, rather than mea­sur­ing lat­i­tude in terms of the length of the mid­sum­...

    The "lat­i­tude" (ab­bre­vi­a­tion: Lat., φ, or phi) of a point on Earth's sur­face is the angle be­tween the equa­to­r­ial plane and the straight line that passes through that point and through (or close to) the cen­ter of the Earth.[n 3] Lines join­ing points of the same lat­i­tude trace cir­cles on the sur­face of Earth called par­al­lels, as they are par­al­lel to the equa­tor and to each other. The north pole is 90° N; the south pole is 90° S. The 0° par­al­lel of lat­i­tude is des­ig­nated the equa­tor, the fun­da­men­tal plane of all ge­o­graphic co­or­di­nate sys­tems. The equa­tor di­vides the globe into North­ern and South­ern Hemi­spheres. The "lon­gi­tude" (ab­bre­vi­a­tion: Long., λ, or lambda) of a point on Earth's sur­face is the angle east or west of a ref­er­ence merid­ian to an­other merid­ian that passes through that point. All merid­i­ans are halves of great el­lipses (often called great cir­cles), which con­verge at the north and south poles. The merid­ian of th...

    Complexity of the problem

    To com­pletely spec­ify a lo­ca­tion of a topo­graph­i­cal fea­ture on, in, or above Earth, one also has to spec­ify the ver­ti­cal dis­tance from Earth's cen­ter or sur­face. Earth is not a sphere, but an ir­reg­u­lar shape ap­prox­i­mat­ing a bi­ax­ial el­lip­soid. It is nearly spher­i­cal, but has an equa­to­r­ial bulge mak­ing the ra­dius at the equa­tor about 0.3% larger than the ra­dius mea­sured through the poles. The shorter axis ap­prox­i­mately co­in­cides with the axis of ro­ta­tio...

    Common baselines

    Com­mon height base­lines include 1. The surface of the datum ellipsoid, resulting in an ellipsoidal height 2. The mean sea level as described by the gravity geoid, yielding the orthometric height 3. A vertical datum, yielding a dynamic heightrelative to a known reference height. Along with the lat­i­tude ϕ{\\displaystyle \\phi } and lon­gi­tude λ{\\displaystyle \\lambda }, the height h{\\displaystyle h} pro­vides the three-di­men­sional ge­o­detic coordinates or ge­o­graphic coordinatesfor a loca...


    In order to be un­am­bigu­ous about the di­rec­tion of "ver­ti­cal" and the "sur­face" above which they are mea­sur­ing, map-mak­ers choose a ref­er­ence el­lip­soid with a given ori­gin and ori­en­ta­tion that best fits their need for the area they are map­ping. They then choose the most ap­pro­pri­ate map­ping of the spher­i­cal co­or­di­nate sys­tem onto that el­lip­soid, called a ter­res­trial ref­er­ence sys­tem or ge­o­detic datum. Da­tums may be global, mean­ing that they rep­re­sent t...

    To es­tab­lish the po­si­tion of a ge­o­graphic lo­ca­tion on a map, a map pro­jec­tion is used to con­vert ge­o­detic co­or­di­nates to two-di­men­sional co­or­di­nates on a map; it pro­jects the datum el­lip­soidal co­or­di­nates and height onto a flat sur­face of a map. The datum, along with a map pro­jec­tion ap­plied to a grid of ref­er­ence lo­ca­tions, es­tab­lishes a grid system for plot­ting lo­ca­tions. Com­mon map pro­jec­tions in cur­rent use in­clude the Uni­ver­sal Trans­verse Mer­ca­tor (UTM), the Mil­i­tary Grid Ref­er­ence Sys­tem (MGRS), the United States Na­tional Grid (USNG), the Global Area Ref­er­ence Sys­tem (GARS) and the World Ge­o­graphic Ref­er­ence Sys­tem (GEO­REF).Co­or­di­nates on a map are usu­ally in terms nor­thing N and east­ingE off­sets rel­a­tive to a spec­i­fied ori­gin. Map pro­jec­tion for­mu­las de­pend in the geom­e­try of the pro­jec­tion as well as pa­ra­me­ters de­pen­dent on the par­tic­u­lar lo­ca­tion at which the map is pro­jected. T...

    Every point that is ex­pressed in el­lip­soidal co­or­di­nates can be ex­pressed as an rec­ti­lin­ear x y z (Carte­sian) co­or­di­nate. Carte­sian co­or­di­nates sim­plify many math­e­mat­i­cal cal­cu­la­tions. The Carte­sian sys­tems of dif­fer­ent da­tums are not equivalent.

    On the GRS80 or WGS84 spher­oid at sea level at the equa­tor, one lat­i­tu­di­nal sec­ond mea­sures 30.715 me­tres, one lat­i­tu­di­nal minute is 1843 me­tres and one lat­i­tu­di­nal de­gree is 110.6 kilo­me­tres. The cir­cles of lon­gi­tude, merid­i­ans, meet at the ge­o­graph­i­cal poles, with the west-east width of a sec­ond nat­u­rally de­creas­ing as lat­i­tude in­creases. On the equa­tor at sea level, one lon­gi­tu­di­nal sec­ond mea­sures 30.92 me­tres, a lon­gi­tu­di­nal minute is 1855 me­tres and a lon­gi­tu­di­nal de­gree is 111.3 kilo­me­tres. At 30° a lon­gi­tu­di­nal sec­ond is 26.76 me­tres, at Green­wich (51°28′38″N) 19.22 me­tres, and at 60° it is 15.42 me­tres. On the WGS84 spher­oid, the length in me­ters of a de­gree of lat­i­tude at lat­i­tude φ (that is, the dis­tance along a north–south line from lat­i­tude (φ − 0.5) de­grees to (φ + 0.5) de­grees) is about 1. 111132.92−559.82cos⁡2φ+1.175cos⁡4φ−0.0023cos⁡6φ{\\displaystyle 111132.92-559.82\\,\\cos 2\\varphi +1.175\\,...

    Geo­sta­tion­ary satel­lites (e.g., tele­vi­sion satel­lites) are over the equa­tor at a spe­cific point on Earth, so their po­si­tion re­lated to Earth is ex­pressed in lon­gi­tude de­grees only. Their lat­i­tudeis al­ways zero (or ap­prox­i­mately so), that is, over the equa­tor.

    Sim­i­lar co­or­di­nate sys­tems are de­fined for other ce­les­tial bod­ies such as: 1. A similarly well-defined system based on the reference ellipsoid for Mars. 2. Selenographic coordinates for the Moon

    Portions of this article are from Jason Harris' "Astroinfo" which is distributed with KStars, a desktop planetarium for Linux/KDE. See The KDE Education Project - KStars

  7. Geographic coordinate system - WikiMili, The Best Wikipedia ...

    A geographic coordinate system is a coordinate system that enables every location on Earth to be specified by a set of numbers, letters or symbols. [note 1] The coordinates are often chosen such that one of the numbers represents a vertical position and two or three of the numbers represent a horizontal position; alternatively, a geographic position may be expressed in a combined three-dimensional Cartesian vector.

  8. Geographic coordinate seestem - Wikipedia

    The circles parallel tae the equator is lines o constant latitude, or parallels. The graticule determines the latitude an longitude o poseetion on the surface. A geographic coordinate seestem is a coordinate seestem that enables ilka location on the Yird tae be specified bi a set o nummers or letters. The coordinates are aften chosen sae that ane o the nummers represents vertical poseetion, an twa or three o the nummers represent horizontal poseetion.

  9. Geographic coordinate conversion - Wikipedia

    From Wikipedia, the free encyclopedia In geodesy, conversion among different geographic coordinate systems is made necessary by the different geographic coordinate systems in use across the world and over time.

  10. Spatial reference system - Wikipedia

    A spatial reference system (SRS) or coordinate reference system (CRS) is a coordinate-based local, regional or global system used to locate geographical entities. A spatial reference system defines a specific map projection, as well as transformations between different spatial reference systems.

  11. Coordonate geografice - Wikipedia

    Sistemul de coordonate geografice este un sistem de referință care utilizează coordonatele unghiulare, latitudine (nordică sau sudică) și longitudine (estică și vestică) și servește la determinarea unghiurilor laterale ale suprafeței terestre (sau mai general ale unui sferoid).