Global Positioning System
GPS is one of those technologies that never fails to amaze you when you sit and think about how it works. When you also consider that a phone you can put in your pocket is capable of using it too, it is even more mind-numbingly extraordinary.
Tip
Warning: If you were born after 1990, you might not understand the previous paragraph and probably think that GPS is quite dull.
The system works with 27 satellites in space known as the GNSS. Out of these, 24 of the satellites are active and three are a backup. Each satellite orbits the Earth every 12 hours constantly broadcasting the changing position data.
By performing calculations on data from at least three of these satellites, our device can provide us with a location in the world in longitude and latitude. Oversimplifying a little (ok, oversimplifying quite a lot), these are the degrees from the poles and equator. They are extremely precise values, as we will see, and therefore accurate potentially to five meters...
