Buying a Satellite Navigation (Satnav) system for your car.
Once they were only for the rich and were only fitted in very high end cars but today SatNav systems are available to all. You can either opt for the relatively expensive in-car fitted systems or you can go for the handheld or portable units. This article is about the latter.
What is SatNav?
SatNav is a navigational system that comprises of two elements, a GPS data receiver and a CPU/display unit. The receiver receives its information from orbiting GPS navigational satellites and communicates this information to the CPU/display unit. From the signal the unit is able to compute its exact location on the planet. The data receiver usually receives data from 7 or 8 different satellites and it is by comparing the data received from the different satellites that the CPU can compute the position.
The unit displays road maps of the area along with an indicator showing the current position and heading of the car.
FeaturesThe units allow you to plan a journey ahead of time. The unit will guide you to your chosen destination by displaying a map of your current area, the road that you should follow is usually shown in a different colour. Most now have voice instructions so the unit will tell you, when you are approaching a junction, which turning you should take. The units are also capable of making real time adjustments to the route, this means that if you go the wrong way the until will recalculate the route to your destination taking into account the wrong turning you have just made. The display can also show other information like speed of the car, distance to next turning, time to destination, average speed etc.
MapsThe maps for the unit can be loaded for the different regions you visit, so there may be a map of the UK and another for France and so on. Most modern units store the maps on a removable memory cards like SD cards or similar memory card but some units read directly from a CD or DVD. The display can be set to show the conventional flat map view or the new 3D view that shows a view as if the camera for the display was above you and looking forward. This view is very good and clear.
TrafficSome units offer systems that will warn you of road works/traffic jams etc as they happen, and offer suggestion as to how to avoid them.
POIMost units have Points of Interest (POIs) incorporated into them that will show things like garages, restaurants, historic sites, airport and ferries etc. You can also add your own POIs of your favourite places. One POI that is very popular is the location of all the speed cameras and accident black spot locations.
WeatherAnother feature that is becoming increasingly available is the weather for a location. The system will tell you the weather at a certain location on the map i.e. at that beach location you are planning to visit.
UsageWhen you want to plan a journey you will need to enter the start and end destination, this can be done in a number of ways, the city, street and house number. The street intersections, the post codes or a location chosen on the on screen map. The start can be done in the same way with the addition of the present location as the starting point (remember the unit knows where you are). There are then itinerary or way points, these allow you to program destinations along the way. Finally you are usually presented with choices of routes with choices like, Fastest Route, Shortest Route, Scenic Route, Avoid Motorways etc some have the choice to avoid toll charges.
FittingThe units can be fitted into the car in a number of ways but the 2 most popular ways are with a mounting bracket that has a strong suction cup. This cup sticks to the windscreen. The second way is a bracket that fixed to the cars air vents, this method can be very good but requires a fixing for each type of car. The unit is then fitted to the brackets and adjusted to give the driver the best viewing angle.
There are dozens of systems available now with a variety of choices of the options available. You need to choose which of the above options are important to you and then choose the unit that best suits you or your budget.
You can see a large variety of different units at different costs at my favourite comparison site www.wangled.co.uk just type in Mobile GPS
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About the Author
Paul Davies is a professional engineer and product reviewer, he submits articles on product guides and reviews. All his articles can be seen on the premium shopping comparison site www.wangled.co.uk