What is the shortest route to the next stop or the agreed meeting point? Global positioning systems (GPS) have become a routine part of everyday life for most people. Until now, however, the minimum number of GPS satellites needed to determine the exact position of a mobile phone or other navigation device has remained a matter of conjecture. Researchers have now proved that a precise location can be determined in most cases with five or more satellites. At present, we can generally be sure of having contact to only four satellites.
Geiger Mueller News Service