GPS navigation

GPS navigation in cars
As time goes on, more and more people are relying on GPS systems installed into their car to guide them on a journey. These are usually to places they have never been before. No doubt they’re great systems, but there are pitfalls when using one, and pitfalls when buying one.

What is GPS?
GPS stands for Global Position System. It was designed by the US military for accuracy in long range attacks, surveillance, and R&D. There are currently about 2 dozen GPS satellites in orbit. They can calculate your position from your signal, its position and three or more satellites. This is a technique called trilateration (for more info on trilateration, click here. There are two levels of accuracy – the military one, which is about 3m, and the civilian one, which is about 15m.

Who are the suppliers of in-car navigation systems?
There are many suppliers – Garmin, TomTom, NavMan, Mitec to name a few. It is important to look around and see what you are willing to pay, and what is available. Don’t buy something because someone else says it’s good.

Why are they good?
Navigation systems tend to replace maps. Maps that get used a lot tend to get dog-eared and pages can go missing. You can also set the system to guide you to your destination, and it will give clear directions where to turn.

Why are they bad?
First things first, people are beginning to rely too much. There are cases where people have gone off the road following the instructions of the GPS, regardless of what the roads signs said – especially more so in construction zones, which may change condition daily. Also, the map in the system may become old – new roads may not have been added in. It’s possible to update the map – most companies use cards or a CD which can be replaced, but is far more expensive.