GEO
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World Geodetic System - Wikipedia, the free encyclopedia
The World Geodetic System is a standard for use in cartography , geodesy , and navigation . It comprises a standard coordinate frame for the Earth , a standard spheroidal reference surface (the datum or reference ellipsoid ) for raw altitude data, and a gravitational equipotential surface (the geoid ) that defines the nominal sea level . The latest revision is WGS 84 (dating from 1984 and last revised in 2004), which was valid up to about 2010. [ 1 ] Earlier schemes included WGS 72 , WGS 66 , and WGS 60 . WGS 84 is the reference coordinate system used by the Global Positioning System . The WGS 84 meridian of zero longitude is the IERS Reference Meridian , [ 3 ] 5.31 arc seconds or 102.5 metres (336.3 feet) east of the Greenwich Prime Meridian at the latitude of the Royal Observatory . [ 4 ] [ 5 ]
Public Domain Contribution Requirement . Since the author(s) released this work into the public domain, in order to maintain this work's public domain status, all contributors to this page agree to release their contributions to this page to the public domain as well. Contributors may indicate their agreement by adding the public domain release template to their user page per the Voluntary Public Domain Declarations instructions . Unreleased contributions may be reverted/removed. Thanks to everyone who participated in the Geo Microformat BOF at O'Reilly's Where 2.0 conference , and in particular to Nat Torkington and Vee McMillen of O'Reilly for arranging and hosting the BOF . Thanks to Chris Hibbbert for providing the real world geo-caching example .