Definition
A coordinated group of satellites working together as a single system to provide continuous coverage of the Earth. In GPS, the constellation consists of a planned arrangement of satellites in specific orbits so that a sufficient number are always visible from any point on the Earth's surface to allow position fixing.
Plain English
A network of satellites arranged in space so that, no matter where you are or what time it is, enough of them are overhead at once to give you a position fix.
Context Anchor
Seen in discussions of GPS navigation, satellite signal coverage, and Selective Availability.
Derivation
From the Latin 'constellatio,' meaning a group of stars. Astronomers used it for patterns of stars seen together in the sky. The aviation/space use carries the same idea: a deliberate group of objects in the sky that function as a set, not individually.
Why Pilots Care
Reliable coverage from the constellation maintains accurate GPS position even when Selective Availability is in use.
Analogy
Think of the constellation like a team of lookout points spread around Earth. One lookout is not enough, but several in different places let the receiver work out its position.
Intuition Check
Do not read constellation as a pattern of stars in the night sky. Here it means a planned group of navigation satellites working together.
Example Sentence 1
The GPS satellite constellation is designed so that at least four satellites are in view from anywhere on Earth at any time.
Example Sentence 2
Before departure the pilot confirmed that enough satellites from the constellation were visible for reliable navigation.