Satellites are used to figure out a receiver's location from space, as a satellite's exact position is known at any time. This is a significant reason for GPS tracking to be so accurate. Ground ...

The best GPS units offer reliable navigation in even the most off-the-beaten-track areas, including topographical and off-road-specific maps, the ability to mark customizable routes and waypoints ...

We currently have over 30 GPS satellites orbiting the Earth at around 20,200 kilometers or about 12,550 miles above us, with at least four always visible from any point on Earth's surface.