Ground based GPS?

1. Is GPS ground based?
2. What is ground based navigation system?
3. What is the use of ground station for GPS?

Is GPS ground based?

Yes, ground-based GPS transmitters have been a thing since GPS was introduced. Search on "pseudolite" or "GPS pseudolite" ("pseudolite" = "pseudo satellite"). GPS doesn't depend on a transmitter being in orbit -- that just makes each transmitter work over a longer distance.

What is ground based navigation system?

A Ground Based Augmentation System (GBAS) augments the existing Global Positioning System (GPS) used in U.S. airspace by providing corrections to aircraft in the vicinity of an airport in order to improve the accuracy of, and provide integrity for, these aircrafts' GPS navigational position.

What is the use of ground station for GPS?

The ground stations use radar to make sure they are actually where we think they are. A receiver, like you might find in your phone or in your parents car, is constantly listening for a signal from these satellites. The receiver figures out how far away they are from some of them.