More than 2 dozen satellites which are orbiting the earth form the Global Positioning System (GPS). The GPS unit and Sat Nav in your car can guide you in finding your location and the shortest route to reach your destination. The unit consists of a receiver and a mini computer provided with route maps. The GPS keeps on guiding you while taking diversions and also it will find out the correct route whenever you make a wrong turn. The Sat Nav system can also provide information regarding speed of the vehicle and accordingly probable time of reaching the destination, weather forecast, altitude and alerts on speed monitors, red light signals, traffic block etc. When you drive your car to a place that is unfamiliar to you, GPS in the car can enable you to save a lot of time by providing instant information regarding the route and traffic. Sat Nav is equally useful for businessmen, tourists and all other types of travelers.

An ideal GPS system should have a voice-guidance feature so that once a particular route is taken it will provide verbal instructions regarding diversions to be taken. A portable GPS unit is more ideal than the other type which is permanently fixed to the car. Portable GPS unit will be compact and can be easily shifted from one car to another. Thus it can be shared among a few people. Portable GPS can be attached to the wind screen of the car and can be charged through a cable from the cigarette lighter of the car.

When you buy your Sat Nav, it must have the mapping software either already loaded or in the form of a memory card which slots into the unit. You may also purchase maps of different countries which can be used during your travels abroad. Digital maps can be easily updated with the changes in the routes. They also provide useful information such as speed camera data, postal codes, places of tourist attraction, positioning of house numbers etc. The ideal map will provide a 3D view of the route which is found out by the GPS according to your requirements like the shortest, fastest etc. The periodically revised maps can be purchased either as SD cards or downloaded from internet.

GPS units with touch screens are the easiest to use. Entering the address of your destination using the touch screen keyboard is the usual method of operation of Sat Nav. Those who can listen and follow the voice instructions need not view the screen continuously. The best GPS & Sat Nav unit can provide information regarding location of petrol stations, traffic condition ahead etc. Sat Navs of different screen sizes are available. However, 3.5” diagonal screen size is considered as the standard.

While buying the GPS unit, you must choose the voice feature suitable to you from a variety of accents and languages. Your Sat Nav must be able to locate the nearest restaurants, parks, supermarket, hospital, post office etc.

Portable GPS unit can be easily removed from the car after your travel so as to prevent theft.

The user interface of the Sat Nav should be easy to use and the touch screen should be responsive. The screen of the Sat Nav should be visible in bright sunlight. Before buying the system, the power lead must be checked. For small trips and shifting the unit from car to car, battery powered units are more suitable. The battery must ensure that it will last for a minimum duration of 4 hours. When you buy a Sat Nav with Bluetooth capability, you can sync the device with your mobile phone so that while driving, you can make and receive phone calls hand-free.

Though a GPS unit with larger screen size will be easier to use, it will be costlier and also difficult to carry around.

There are hundreds of different Sat Nav models in the market and the prices vary within a wide range. The size of the screen and the additional features are the two main factors for fixing the price. Hence while buying a new Sat Nav, the buyer must know about the new features and see whether those features are required. Basically, an ideal Sat Nav must meet the following specifications:

  • A portable device with a screen of standard size with clarity
  • Audible, visible, simple and clear audio and video alerts
  • Simple, easy to operate user interface
  • Easy-to-navigate menus
  • Useful extra features