How The GPS System Works. How the GPS System Works. 24 satellites + spares 6 orbital planes 55° inclination Each satellite orbits twice every 24 hours. At least 4 satellites visible any time of day, anywhere in the world. A 2 Dimensional Example.
A small cluster of satellites can result in a large position error.
Similar to triangulating with mountain peaks that are
close to one another.
Check your EPE!