Definition
A space-based radio navigation system that provides users with highly accurate position, velocity, and time information anywhere on or near the Earth. The system relies on a constellation of satellites broadcasting precise timing signals; a receiver calculates its own position by measuring the time it takes signals from at least four satellites to arrive.
Plain English
A network of satellites circling the Earth that send out signals. A receiver in the aircraft listens to several of those signals at once and uses the tiny differences in their arrival times to work out exactly where it is, how fast it is moving, and what time it is.
Context Anchor
Pilots encounter GPS on cockpit navigation displays, flight plans, moving maps, and approved GPS-based routes or approaches.
Derivation
‘Global’ means worldwide. ‘Positioning’ comes from the Latin positio, meaning ‘placing’ or ‘setting in a place.’ Together the name describes exactly what the system does: it places you on a position, anywhere in the world.
Why Pilots Care
GPS supplies accurate navigation data without depending on ground-based radio aids, allowing direct routing and safer operations when weather or terrain limits other options.
Intuition Check
GPS is not the cockpit screen or moving map itself. GPS is the satellite-based system that supplies position, movement, and time information to the equipment showing it.
Example Sentence 1
She loaded the flight plan into the GPS and selected direct-to the destination airport.
Example Sentence 2
During the cross-country flight the GPS showed the direct route and estimated time of arrival.