Definition
A general term referring to any worldwide satellite-based positioning, navigation, and timing system that allows a suitably equipped aircraft to determine its position, velocity, and time using signals from a constellation of orbiting satellites. GNSS is the umbrella name covering individual systems such as the U.S. GPS, the European Galileo, the Russian GLONASS, and China's BeiDou, along with augmentation systems that improve their accuracy and integrity for aviation use.
Plain English
GNSS is the broad name for any system that uses satellites in space to tell an aircraft exactly where it is, how fast it is moving, and what time it is. GPS is the most familiar example, but it is one of several such systems worldwide.
Context Anchor
Seen in avionics manuals, flight planning, instrument procedures, and discussions of satellite-based navigation equipment.
Derivation
Built from three plain words: 'global' (worldwide), 'navigation' (finding your way), and 'satellite system' (a network of spacecraft working together). The term was chosen as a generic label so it would cover any country's satellite navigation network, not just the American GPS.
Why Pilots Care
It enables accurate worldwide navigation and supports precision approaches without ground infrastructure.
Analogy
GNSS is the umbrella name; GPS is one system under that umbrella. If someone says GNSS, they are talking about the whole satellite navigation category.
Intuition Check
GNSS does not mean exactly the same thing as GPS. GPS is one GNSS; GNSS is the broader category of satellite navigation systems.
Example Sentence 1
The approach was coded as an RNAV (GNSS) procedure, so any approved satellite navigation receiver in the aircraft could fly it.
Example Sentence 2
GNSS signals allow the aircraft to fly a precise path without relying on ground radio beacons.