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.
Plain English
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.
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.
Derivation
"Ground-based" simply means the transmitting equipment sits on the ground, in contrast with satellite-based systems where the signal source is in orbit. The distinction matters because the geometry, range, and failure modes of each are very different.
Why Pilots Care
These systems remain required knowledge for instrument ratings and serve as reliable backups when satellite navigation is unavailable.
Intuition Check
Ground-based navigation does not mean navigating while the airplane is on the ground. It means the navigation help comes from equipment located on the ground.
Example Sentence 1
The instructor explained that ground-based navigation, using VOR stations along the route, would be their primary method if the GPS failed in flight.
Example Sentence 2
Many instrument approaches still rely on ground-based navigation facilities when GPS is not authorized.