National Aeronautics and Space Administration

Global Navigation Satellite System (GNSS) receivers detect, decode, and process signals from the GNSS satellites (e.g., currently the Global Position ing System, GPS, and GLObal NAvigation Satellite System, GLONASS, and, in the future, the European Galileo, Chinese Beidou/Compass, and Japanese QZSS systems). The satellites transmit the ranging codes on two radio-frequency carriers, allowing the locations of GNSS receivers to be determined with varying degrees of accuracy, depending on the receiver and post-processing of the data.

The GNSS technique