Definition
Aircraft avionics that determine position, track, and guidance information by receiving and processing signals from a constellation of navigation satellites, most commonly the Global Positioning System (GPS). The equipment computes the aircraft's three-dimensional position by measuring the time it takes for signals to travel from multiple satellites, and presents course, distance, and waypoint information to the pilot for use in navigation.
Plain English
Onboard equipment that uses signals from satellites in space to figure out where the aircraft is and where it's going.
Context Anchor
Seen in discussions of modern instrument panels, flight instruments, and navigation systems used during instrument flying.
Derivation
Satellite comes from the Latin satelles, meaning attendant or companion -- something that travels alongside something larger. Navigation comes from the Latin navigare, to sail a ship. Together the term describes navigation guided by companion objects orbiting Earth -- a useful image because the satellites are quietly traveling overhead, providing reference points the aircraft uses to fix its position.
Why Pilots Care
Enables precise direct routing and instrument approaches without reliance on ground stations, improving safety and efficiency in IFR operations.
Intuition Check
Satellite-based does not mean the airplane is being controlled by satellites or connected to the internet. It means the equipment listens to satellite signals and uses them to calculate the airplane's position.
Example Sentence 1
Before departing on the IFR flight, the pilot confirmed the satellite-based navigation equipment was receiving a strong signal and had loaded the correct flight plan.
Example Sentence 2
During the instrument approach, satellite-based navigation equipment provided continuous position updates to the flight display.