How does GPS work? The science behind GPS Now that you know how
GPS has been developed, it's time to dive deeper into the
subject and find out exactly what happens before your navigation
device tells you exactly where you are. The location of the
satellites To work out where you are, your navigation device
needs to know two things: a. The location of at least four
satellites above you, b. Your distance from each of those
satellites. The distance of the satellites A navigation device
works out its distance from a GPS satellite from the time it
takes the signal to travel to the receiver from the satellite.
The fourth satellite In satellite navigation perfect timing is
everything; the fourth satellite checks the time measurement of
the other three satellites to make sure the information about
your location is as accurate as possible. Atmosphere-induced
error & Multipath error So we’ve got perfect timing and we know
the satellite's exact position. But up to now our calculations
have been based on the speed of lig