Definition
A general term for any worldwide position-fixing system that uses a constellation of satellites to provide an aircraft receiver with three-dimensional position, velocity, and time information. GNSS is the umbrella term covering systems such as the United States' GPS, Europe's Galileo, Russia's GLONASS, and China's BeiDou. In aviation, a GNSS receiver computes the aircraft's position by measuring the time it takes for signals to arrive from multiple satellites simultaneously.
Plain English
GNSS is the catch-all name for satellite-based navigation. Your receiver listens to signals from satellites in space and uses them to work out exactly where the aircraft is, how fast it's moving, and the precise time.
Context Anchor
Seen in instrument navigation, approach chart notes, cockpit navigation equipment, and discussions of satellite-based position information.
Derivation
Global = worldwide. Navigation = finding your way. Satellite = the orbiting transmitters. System = the whole network working together. The word 'system' is important here because GNSS includes not just the satellites but also the ground stations that monitor them and the receivers in the aircraft.
Why Pilots Care
Provides continuous, high-accuracy navigation that replaces many ground-based aids and enables modern instrument procedures.
Grounding Statement
The basic idea is that the aircraft compares signals from several satellites to work out where it is.
Intuition Check
GNSS does not mean only one specific system. It is the broad name for satellite navigation systems; the U.S. Global Positioning System is one example.
Example Sentence 1
The approach was coded for GNSS, so either GPS or a multi-constellation receiver could fly it.
Example Sentence 2
During the flight the GNSS receiver updated the aircraft location every second.