The World Geodetic System (WGS) is a standard for use in cartography, geodesy, and navigation including GPS.
It comprises a standard coordinate system for the Earth, a standard for raw altitude data, and a geoid that defines the nominal sea level. The latest revision is WGS 84.
Images for kids
Handheld GPS receiver indicating the Greenwich meridian is 0.089 arcminutes (or 5.34 arcseconds) west to the WGS84 datum
Doppler satellite ground stations providing data for WGS 72 development
Worldwide geometric satellite triangulation network, BC-4 cameras