Plain English Meaning
Finding your way in the air by tuning in to radio signals sent from stations on the ground, and using those signals to know where you are or which way to fly.
Full Definition
A category of air navigation that relies on radio signals transmitted from fixed stations on the ground — such as VOR, NDB, DME, ILS, and TACAN — to determine an aircraft's position, track, or course relative to those stations.
Context Anchor
Seen when studying navigation systems that rely on stations or facilities installed on the ground, such as during enroute navigation and instrument training.