Plain English Meaning

Navstar satellites are the actual satellites that make GPS work. They circle the Earth and send out signals that your GPS receiver listens to in order to figure out where you are.

Full Definition

The constellation of U.S. Department of Defense satellites that broadcast the radio signals used by GPS receivers to determine position, velocity, and time. Each Navstar satellite continuously transmits coded signals from medium Earth orbit, and a GPS receiver uses signals from at least four of them to calculate a three-dimensional fix.

Context Anchor

Seen in GPS system descriptions, especially when learning how an aircraft GPS gets position information from the space part of the GPS system.