Discover the World Geodetic System with our Quiz!

Geodetic reference system

• The World Geodetic System (WGS) is a standard used in cartography, geodesy, and satellite navigation including GPS.
• The current version, WGS 84, defines an Earth-centered, Earth-fixed coordinate system and a geodetic datum.
• WGS 84 also describes the associated Earth Gravitational Model (EGM) and World Magnetic Model (WMM).
• The standard is published and maintained by the United States National Geospatial-Intelligence Agency.
• A unified geodetic system for the whole world became essential in the 1950s for several reasons.
• In the late 1950s, the United States Department of Defense began to develop the needed world system to which geodetic data could be referred and compatibility established between the coordinates of widely separated sites of interest.
• The development of WGS 84 was based on improved data, increased data coverage, new data types and improved techniques.
• Observations from Doppler, satellite laser ranging and very-long-baseline interferometry (VLBI) constituted significant new information.
• WGS 84 is the reference system used by the Global Positioning System.
• The WGS 84 reference ellipsoid was based on GRS 80, but it contains a very slight variation in the inverse flattening.
• The WGS 84 datum surface is an oblate spheroid with equatorial radius a = 6378137 m at the equator and flattening f = 1/298.257223563.
• The current version of WGS 84 uses EGM2008 and WMM2020.