GPS is the USA’s NAVSTAR ‘Global Positioning System’. It is a space-based global navigation satellite system (GNSS) that provides location and time information in all weather conditions, anywhere on or near the Earth, where there is an unobstructed line of sight to at least four GPS satellites. GPS is maintained by the United States government and is freely accessible with some technical limitations. GPS receivers deliver the position data, without further transformation, in the WGS84 coordinate system.
