The document summarizes the Global Positioning System (GPS). It describes GPS as a worldwide radio navigation system consisting of 24 satellites in orbit that can provide location data within meters anywhere on Earth. It has three segments - the control segment monitors the satellites from ground stations, the space segment consists of the satellites, and the user segment comprises GPS receivers. The document then provides technical details on how GPS determines position using satellite orbital data, signal travel times, and triangulation of distances to multiple satellites.