Although we often tend to hear the words "Sat Nav" and GPS used interchangeably, there is a significant difference between them.
What is GPS?
GPS (Global Positioning System) forms the basis of this new genre of navigational tools and operates through triangulating three or more points with the desired location as the intersection. It is generally accepted that it takes four satellites in orbit around the earth to provide an exact location - three to find it and the fourth to check any errors. The position is then used to calculate latitude, longitude and altitude, and laid over a road map to pinpoint a location within a few feet.
GPS is used not only in driving but also for boating, hiking, on watches, for search and rescue, in aircraft landing devices and a multitude of other commercial applications. Many Android mobile phones or iPhones have a built-in GPS and may require you to be connected to the internet via wireless. You might use this information to find the nearest pizza restaurant or if you're having a hard time finding your way to a friend's house. Some digital cameras use GPS technology to record the exact location a photo was taken.
Currently, no matter which company makes the sat nav device you buy, they all triangulate their GPS from the same satellites.
The GPS system was originally designed in the USA. Several countries including the EU are in the process of developing public access and regional navigation systems as well for the future.
What is a Sat Nav?
Sat Navs(Satellite Navigational) aids serve as GPS receivers and combine mapping software with pre-loaded and pre-programmed maps and graphics alongside these GPS satellite readings to virtually guide you to your destination.
The GPS locks into the Sat Nav receiver in your unit and locates its position on the surface of the earth. Built-in software geared to the part of the world you're travelling in can be purchased and downloaded to help you work out the simplest route between any two points, combine road speeds, and even advise you on road conditions enroute.
This software takes the co-ordinates provided by the GPS and calculates step by step instructions which are constantly updated. You can choose to listen to these audibly so that you essentially have a virtual map reader sitting beside you in the vehicle telling you when to turn, without the argumentation!
Some high-end touch screen GPS receivers even give access to real-time TV broadcasts as well as radio and images from your own vehicle's camera. Bluetooth GPS systems benefit from intelligent technology that allows you to speak directly to the device, make calls via Bluetooth and access travel and weather information.
Even as we become more and more reliant on tools to navigate our way and take the stress out of the journey, remember not to throw common sense to the wind along with your old road maps. Although not infallible, these hand-held navigational devices certainly leave us without much excuse to become lost anymore!