How Do Sat Navs Work

So Just How Does a Sat Nav work?

A sat nav is a wonderful piece of technology, Getting us where we need to go with little effort it would seem but how does this incredible device work?

Satelite Navigation is worked by GPS (Global Positioning System) and complex software that create the maps you see on the screen.

There are 26 GPS satelite's orbiting the earth and new one's being built on the ground to replace old one's in space, Each satelite is designed to last 10 year's so new one's are built continuosly. The GPS network we all use is called Navstar and is funded by the U.S Department of Defence (d.o.d).

How It Works

The GPS satelite's transmit signal's and will be picked up on the ground by any GPS reciever or i.e your sat nav. To get a good signal on the ground with your sat nav you need to be recieving at least 4 GPS satelite signals, A GPS receiver "knows" the location of the satellites because that information is included in the transmitted emphemeris data. By estimating how far away a satellite is, the receiver also "knows" it is located somewhere on the surface of an imaginary sphere centred at the satellite. It then determines the sizes of several spheres, one for each satellite. The receiver is located where these spheres intersect.

In other word's the data being picked up by the satelite's form a triangular postion around you, The satelite then compares the data from the other satelite's work's out the distance time and speed from the other's and determine's your position.

GPS transmit two signal's which travel in the line of sight meaning they can travel through Glass, Plastic, Wood, Cloud's etc, but will not travel through solid building's or built up mountain's.

Brief description

A sat nav is worked by the GPS ( 26 ) satelite's that are orbiting the earth, Your sat nav lock's onto 4 of them picking up the signal's they are transmitting forming a triangular position with you in the middle, They then compare the data, time, speed and distance with the other's knowing you are somewhere near them and provide's you with the right information of where you need to go.

Sat Nav's are a great bit of technology and if you dont have one now then you should consider buying one, More than anything it is a massive time saver with a great design and easy to use, I use the Garmin Nuvi and have to say it is a great piece of kit, along with tom tom which is also good:-)