You may not know where you're going, but with a global positioning system (GPS) device installed in your car you never have to worry about getting lost. You can drive around a new town as if you were a lifelong resident.
A GPS device has three basic parts. The receiver taps into the NAVSTAR system originally developed in 1973 by the U.S. Department of Defense for military purposes. The NAVSTAR network consists of 30 satellites orbiting the earth every 12 hours. To determine your position, the receiver locks onto at least four of these satellites and triangulates your position using long-forgotten equations from your trigonometry class.
The GPS device also stores a comprehensive selection of maps. Once it locates your position, the GPS pulls up the appropriate map and overlays your position on it.
Finally, the GPS device has the ability, like such Web sites as MapQuest or Google Maps, to chart your course.
You use a GPS by entering your destination, either by pinpointing it on a map or typing in its address on the touch screen. Your GPS then takes over, locates you, determines the best route from your current location to your destination, and provides you with voice commands as you move across the landscape.
GPS devices are designed to be forgiving. If you miss a turn, the GPS will recalculate your route and provide new directions—without comment!
When choosing a GPS, take into account the following considerations:
- Screen Quality. If you can't make out the images on the screen, your GPS will not be much help. The ideal screen is big, easy to read in bright sunlight, and can be seen from a wide viewing angle. If you can, try it out before you buy it.
- Map Quality. Make sure the GPS comes with maps for your area. Before making your purchase, find out how much it will cost to update the maps you use frequently and to buy maps for other areas of the country that you intend to visit.
- Size. To work well, a GPS antenna has to have a clear view of the sky. If you choose a portable GPS system, this usually means placing it on the top of your dashboard. You should decide how much space you can afford to give up without impeding your vision.
If you are buying a new car, consider opting for a factory-installed, in-dash navigation system. If you are considering a GPS for your current car, you can have one professionally installed or choose a portable model. Typically, a portable GPS will attach to your dashboard with a suction cup. Like virtually every other technology from music players to video cameras, GPS is even making its appearance in cell phones. The only drawback: the screen size is too small to be read conveniently in a moving automobile.