The Global Positioning System (GPS) is a technical marvel made possible by a group of satellites in earth orbit that transmit precise signals, allowing GPS receivers to calculate and display accurate location, speed, and time information to the user.
By capturing the signals from three or more satellites (among a constellation of 31 satellites available), GPS receivers are able to use the mathematical principle of trilateration to pinpoint your location.
With the addition of computing power, and data stored in memory such as road maps, points of interest, topographic information, and much more, GPS receivers are able to convert location, speed, and time information into a useful display format.
GPS was originally created by the United States Department of Defense (DOD) as a military application. The system has been active since the early 1980s, but began to become useful to civilians in the late 1990s. Consumer GPS has since become a multi-billion dollar industry with a wide array of products, services, and Internet-based utilities.
GPS works accurately in all weather conditions, day or night, around the clock, and around the globe. There is no subscription fee for use of GPS signals. GPS signals may be blocked by dense forest, canyon walls, or skyscrapers, and they don’t penetrate indoor spaces well, so some locations may not permit accurate GPS navigation.
GPS receivers are generally accurate within 15 meters, and newer models that use Wide Area Augmentation System (WAAS) signals are accurate within three meters.
While the U.S. owned and operated GPS is currently the only active system, five other satellite-based global navigation systems are being developed by individual nations and by multi-nation consortiums.
Basics of GPS
GPS technology has found its way into a wide variety of consumer products that can help you in your travels for business or pleasure. Which type of GPS unit is right for you? What features are available? Once you know the class of product that will best suit your needs, and the features offered, you will be well-prepared to shop and compare.
Sales of aftermarket in-car GPS devices have more than doubled over the past two years, and automotive is the fastest-growing segment of the GPS market. Why? Better and brighter color screens, improved accuracy and usability of maps and directions, added features such as traffic alerts, the ability to wirelessly link a mobile phone to an in-car unit to get hands-free mobile speaker-phone use… all of these reasons and more.
You just got an in-car GPS navigator. Here are some tips for quick setup, safety, and getting the most from your GPS. Handheld GPS units have dramatically changed outdoors travel, replacing map and compass with moving digital maps, and precise location, elevation, topographic and other data. GPS products for cycling and running provide a great way to track and record your workouts. Marine GPS devices are a pleasure to use, and dramatically enhance all-weather, all-light-condition safety. Portable aviation units offer intuitive, moving-map views with navigation overlays, providing a great supplement to a plane's instrumentation.