Definition
A navigation system that uses radio signals transmitted from a network of satellites in orbit to determine an aircraft's position, altitude, velocity, and time. The receiver in the aircraft picks up signals from multiple satellites simultaneously and calculates its location based on the time it takes those signals to arrive. GPS is the most widely used example in aviation.
Plain English
A way for an aircraft to figure out exactly where it is by listening to radio signals sent down from satellites circling the Earth.
Context Anchor
Seen in GPS discussions, instrument flying, and avionics manuals when describing how GPS provides position and navigation information.
Derivation
Satellite' comes from the Latin satelles, meaning attendant or companion -- something that travels alongside a larger body. 'Radio' refers to the radio-frequency signals the satellites broadcast. Together the phrase simply describes a navigation system whose signal sources are companions orbiting the Earth rather than ground stations.
Why Pilots Care
Provides worldwide positioning independent of ground facilities, enabling GPS approaches and precise enroute navigation.
Intuition Check
Do not read “radio” here as voice communication. In this term, radio means invisible signals sent from satellites to the aircraft's receiver.
Example Sentence 1
GPS is the satellite-based radio navigation system most pilots rely on for en route and approach navigation.
Example Sentence 2
During the RNAV approach the satellite-based radio navigation system displayed the aircraft's distance to the final approach fix.