The World Geodetic System (WGS) is a standard for use in cartography, geodesy, and satellite navigation including GPS. This standard includes the definition of the coordinate system's fundamental and derived constants, the normal gravity Earth Gravitational Model (EGM), a description of the associated World Magnetic Model (WMM), and a current list of local datum transformations.
The latest revision is WGS 84 (also known as WGS 1984 ensemble: EPSG:4326 for 2D CRS, EPSG:4979 for 3D CRS and EPSG:4978 for geocentric 3D CRS), established and maintained by the United States National Geospatial-Intelligence Agency since 1984, and last revised in January 2021 (G2139 frame realization). WGS 84 ensemble is static, while frame realisations have an epoch. Earlier schemes included WGS 72, WGS 66, and WGS 60. WGS 84 is the reference coordinate system used by the Global Positioning System.
As CRS standard, and expressing by URN,
urn:ogc:def:crs:EPSG::4326, it is composed of:
- a standard reference ellipsoid model, named
- and this ellipsoid is located a standard horizontal datum, named