Definition
Global Navigation Satellite Systems (GNSS) is the umbrella term for any satellite-based system that provides worldwide position, velocity, and time information to a receiver on the ground, in the air, or at sea. It includes the U.S. GPS, Russia's GLONASS, Europe's Galileo, China's BeiDou, and any augmentation systems that improve their accuracy or integrity. A GNSS receiver determines its position by measuring the precise time it takes for signals from multiple satellites to reach it, then calculating distances to each satellite and resolving its location in three dimensions.
Plain English
GNSS is the general name for satellite navigation. GPS is one example of a GNSS, but there are others run by different countries. A receiver listens to signals from several satellites and works out exactly where it is.
Context Anchor
Seen in instrument flying, navigation equipment discussions, route planning, and reports that describe satellite navigation capability or availability.
Derivation
Global because the satellites cover the whole earth. Navigation because the system's purpose is to tell you where you are and help you get somewhere. Satellite because the signals come from spacecraft in orbit rather than ground stations. The plural 'Systems' is deliberate — GNSS is a category that includes several independent satellite networks, not just one.
Why Pilots Care
Enables precise, worldwide navigation independent of ground-based aids and supports modern instrument procedures.
Intuition Check
GNSS does not mean only GPS. GPS is one satellite navigation system within the broader GNSS category.
Example Sentence 1
The aircraft's avionics use GNSS for primary navigation, drawing position data from both GPS and Galileo satellites.
Example Sentence 2
GNSS signals were used to fly the published arrival procedure into the airport.