Plain English Meaning

Equipment on the ground or in space that sends out signals so pilots can figure out where they are and where they're going.

Full Definition

Ground-based or space-based facilities that transmit signals pilots use to determine position, track a course, or follow an approach. Common examples include VOR stations, NDBs, ILS components, DME, and GPS satellites.

Context Anchor

In the night illusions section, this term appears when discussing featureless terrain, where a pilot may need to rely more on instruments and navigation aids than on outside visual references.

Derivation

A simple of '' — anything that aids . 'Navigation' comes from the Latin navigare, meaning to sail or steer a ship, which carried directly into when pilots needed the same idea: knowing position and direction without .