Definition
The flat, imaginary surfaces in space along which GPS satellites travel around Earth. The GPS constellation uses six orbital planes, each tilted about 55 degrees relative to the equator, with multiple satellites spaced along each plane so that several satellites are visible from any point on Earth at any time.
Plain English
The invisible flat tracks in space that GPS satellites follow as they circle the Earth. There are six of these tracks, arranged so that no matter where you are, enough satellites are overhead to give you a position fix.
Context Anchor
Seen in GPS system descriptions that explain how the satellites are arranged in space.
Derivation
From Latin orbita, meaning 'track' or 'path', and plane meaning 'flat surface'. An orbital plane is literally the flat surface that contains a satellite's circular path around Earth.
Why Pilots Care
Knowing the arrangement ensures pilots understand the reliability of GPS positioning even in areas without ground-based aids.
Analogy
Imagine six hula hoops tilted around a globe at different angles, each holding several satellites spaced evenly along the hoop. Together they form a cage around Earth so that some satellites are always overhead, no matter where you stand.
Grounding Statement
The key idea is that GPS satellites are arranged in organized paths around Earth, not scattered randomly in space.
Intuition Check
Planes does not mean aircraft here. It means flat imaginary surfaces used to describe where satellite paths are located.
Example Sentence 1
GPS satellites are distributed across six orbital planes to ensure continuous global coverage.
Example Sentence 2
A pilot relying on GPS for oceanic navigation benefits from the even spacing of satellites across several orbital planes.