GNSS stands for Global Navigation Satellite System, a general term for satellite constellations providing global, autonomous, geospatial positioning, navigation, and timing (PNT) services. Unlike just GPS (US), GNSS includes multiple systems—GPS, GLONASS, Galileo, BeiDou—allowing receivers to use signals from various satellites for increased accuracy.  The accuracy from these systems has revolutionized mapmaking and enabled easier navigation across oceans and remote terrain.