Originally Posted by
Garfield Cat
I have always wondered about these GPS devices. There must be millions out there just by Garmin alone. When do these satellites run out of the ability to track each one? Will there be a time of over saturation? Or does Garmin just shoot more satellites into orbit to handle the traffic here?
GPS satellites don't/can't track the GPS units. The satellites broadcast signals that the GPS receivers pick up, which allows the GPS receiver to determine where it is. The satellites have no way of knowing where the GPS receivers are. They just orbit and broadcast their signals.
You can get GPS units that also transmit their location to different satellites (not GPS satellites) for the purposes of tracking. This is a service you pay for and is used by trucking companies, trains and other commercial operators. Your Garmin Edge or typical auto GPS can't do this.
The GPS satellites are put up by the US military. There is a EU system (Galileo) and a Russian system (Glonass) too.