What technique does GPS use to determine a location accurately?

GPS determines a location accurately through a technique called trilateration. This method relies on the measurement of distances from several satellites orbiting the Earth. Each satellite transmits a signal that includes the satellite's location and the exact time the signal was sent. A GPS receiver on the ground listens for these signals and calculates how long it took for the signals to arrive.

By knowing the speed of light, the GPS receiver can convert this travel time into a distance from each satellite. Typically, at least four satellites are needed to accurately determine the receiver's position in three-dimensional space (latitude, longitude, and altitude). When multiple distances from different satellites are combined, the GPS receiver can pinpoint a precise location on the Earth’s surface.

In contrast, triangulation would involve determining a position based on angular measurements from known points, which is not how GPS operates. Mapping and geolocation do not provide the methodical approach used by GPS; rather, they are broader concepts encompassing various positioning and navigation techniques.