Global Positioning System

What is it?

The Global Positioning System is a space-based satellite navigation system that provides your location and time information, anywhere in Earth, where there is a clear, unobstructed line to four or more GPS satellites. GPS was invented by the U.S. Department of Defense and Ivan Getting, it cost twelve billion dollars. It is now owned by the American government and accessible to anyone with a GPS reciever.

How does it work?

GPS satellites circle the earth twice a day in a very precise orbit and they transmit signal information to earth. GPS receivers take this information and calculate the user's exact location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the electronic map built in.

What apps use GPS?

Many apps use GPS, obvious apps like maps but also many others. Apps like Facebook and Twitter use GPS to add your location to the bottom of you status or tweet. Also fitness apps like ‘map my ride’ and ‘map my run’ use the GPS. These apps track and save the route you cycle or run and they also tell you how far the routes are. Other apps like ‘AroundMe’ use GPS in another way. This app locates where you are, then tells you where the closes supermarket, restaurants and cinemas are, along with many other places.