The GPS or Global Positioning System is a globalnavigation system used for military and civilian applications alike.
As a positioning system, GPS allows users to map waypoints, tracking their position on a map to within a few meters of their exact location. Civilian use GPS systems are made by companies such as Magellan, Garmin and Trimble.
Hand-held GPS units are often used by hikers and mountain climbers to plot their courses and to accurately reflect exactly where they are. The author once used GPS to organize a helicopter evacuation of an injured motorcycle rider in a remote region of the La Sal mountains in Utah. A reading was taken, coordinates given, and the pilot was able to find us with ease.
GPS is short for (the) Global Positioning System, a satellite navigation system developed by the US Department of Defense. A fleet of more than two dozen GPS satellites broadcasts precise timing signals to GPS receivers, allowing them to accurately determine location anywhere on Earth. In practice, this means that using a GPS device, you can find out where you are in terms of longitude, latitude and altitude.
Atomic clocks on the GPS satellites are set to "GPS time", which is the number of seconds since 00:00:00 UTC, January 6, 1980. UTC is short for Coordinated Universal Time. Today, GPS time is 14 seconds ahead of UTC, because it does not follow leap seconds. That's why new GPS units initially show the incorrect time after achieving a GPS lock for the first time. However, this is usually corrected on the display within 15 minutes once the UTC offset message is received for the first time.
In 1998, Vice President Al Gore announced plans to upgrade GPS with two new civilian signals for enhanced user accuracy and reliability, particularly with respect to aviation safety.
The most recent launch was in September 2005. The oldest GPS satellite still in operation was launched in February 1989.
GPS is coming into common use in cars these days. Most new cars allow you to purchase GPS technology that will help you plot your trip from one location to the next.
The GPS system uses a satellite constellation of 24 satellites in intermediate circular orbits. The orbits are designed so at least four satellites are always within line of sight from almost any place on earth. The constellation also includes three spare satellites in orbit.
GPS was first made available for commercial applications in 1983, after the Soviet Air Force shot down the civilian airliner KAL 007 in restricted Soviet airspace, killing all 269 people on board.
More accurate GPS receivers are used these days in surveying to accurately locate boundaries, structures and so on.
When it was first deployed, GPS included a feature called Selective Availability (or SA) that introduced intentional errors of up to a hundred meters into the publicly available navigation signals, making it difficult to use for guiding long range missiles to precise targets. Additional accuracy was available in the signal, but in an encrypted form that was only available to the United States military, its allies and a few others, mostly government users.
The United States Department of Defense developed the system, officially named NAVSTAR GPS (Navigation Signal Timing and Ranging GPS), and the satellites are managed by the 50th Space Wing at Schriever Air Force Base. Although the cost of maintaining the system is significant, GPS is available for free use in civilian and commercial applications.
In early years, the US military made the civilian application purposefully less powerful than it could. But since August 2000, the GPS civilian application provides the accuracy of GPS signals to within 2 meters (6 ft). Fact is, GPS accuracy can be improved further, to about 1 cm (half an inch) over short distances, using techniques such as Differential GPS (DGPS).
Each satellite repeatedly re-broadcasts the exact time according to its internal atomic clock along with a digital data packet that includes the satellite's precise position, satellite status messages, and an almanac of the approximate position of every other active GPS satellite. The almanac lets GPS receivers use data from the strongest satellite signal to locate other satellites.
1. GPS Discount Sells receivers, fishfinders, chartplotters, and other outdoor products.
2. Discount GPS Navigation Discount GPS Navigation offers a large selection of Garmin and Magellan GPS navigation units and all the accessories at discounted prices.
7. Discount GPS Store Home Page Welcome to Discount GPS Store. We are so sure that our prices are the lowest in the world that if you can find a better price anywhere for any item ...
8. Garmin | GPSDiscountDepot.com | Garmin and Magellan GPS http://www.gpsdiscountdepot.com ... and excellent customer service on a wide variety of portable GPS units from aviation to marine applications and all in between. ...
10. Discount GPS Systems | GPS Auctions | GPS systems for cars is one of the newest hottest trends in today's auto market. Find discount GPS systems here at low prices. We have new and used GPS units for sale ...
11. GPSmart GPSmart is Canada's choice for discount GPS products by Garmin, Magellan, TomTom. GPSmart provides both sales and rentals of GPS products. We pride ourselves on fast ...
14. YouTube :: Tag // discount gps gps, Global Positioning System. Honda Accord custom gauge face (night) ... Cheap Garmin nüvi 205W 4.3-Inch Widescreen Portable GPS Navigator Reviews ...
15. My Discount GPS My Discount GPS. We are still under construction. Please check out our other websites: www.goodfragrancesite.com, www.dvdbuysonline.com, www.superdogshop.com. ...
17. Discount GPS Site Discount GPS Site. great selection & prices. Main Menu. Home. Products ... Discount GPS Site. Main page info... Featured Products. GARMIN MOBILE 20 SENSOR ONLY $163. ...
18. discount gps | Popular Science discount gps. 01.22.10. Most Recent. Most Viewed. Top Rated. Most ... Viewed. discount gps. Most Commented. discount gps. Most Emailed. discount gps. Name. Address ...
20. Compare GPS | bookmarks | oneview You are interested in Compare, GPS, cheap or compare prices? If so, oneview is just right for you! ... Compare prices, cheap, discount for GPS Accessories, products ...
21. Add to Cart Discount GPS Garmin nüvi® 1350T Automotive GPS ... In addition, this ultra-thin GPS has preloaded maps for North America or Europe, announces streets by name, ...
22. Discount Marine GPS This site lists auctions for discount marine GPS units. The marine GPS devices on this site may be used or refurbished, so read the auction before purchasing. ...
24. GPS Discount, Inc. sells name brand GPS receivers ... GPSdiscount.com offers a full line of Garmin and Magellan GPS systems, including Colormaps, Streetfinders, and Mapping software at the lowest prices on the web guaranteed!
25. GPS direct from China (Mainland) Want to find GPS? Find hot sale original Lcd game player with big discount,free shipping&video game,game player,TV game player&Discount brand GPS free Shipping and ...
28. Discount GPS Sales GPS Training offer 10% discount on the RRP of all Garmin GPS units and all Memory-Map Software (All prices shown are the manufacturers RRP less 10 ...
30. Discounted-GPS.com - An Overview of the GPS System Keyword: gps system Word Count: 420 Keyword Density: 9/2.14% Using a GPS System The idea for a GPS tracking device was created and developed by the United States ...
32. vendors 15 years experience in the field providing rock-solid advice about GPS equipment and GPS Software. ... GPS CITY (USA & INTERNATIONAL): Discount prices on tons of GPS gear, ...
33. GPS Discount Guide The king of automotive GPS I really love the 720. I have tried the ... to its popular pocket-sized GPS navigator lineup. As with all nüvis, you get Garmin ...
34. Discount Garmin Nuvi 760 GPS What Makes the Discount Garmin nuvi 760 GPS So Accurate? ... Many models, such as the discount Garmin nuvi 760 GPS, perform many other functions as well. ...
35. discount gps | Popular Science discount gps. 12.25.09. Most Recent. Most Viewed. Top Rated. Most ... Viewed. discount gps. Most Commented. discount gps. Most Emailed. discount gps. Name. Address ...
37. GPS Deals, GPS Coupons, Cheap GPS, GPS Discount & GPS Sale gps deals, gps discount, cheap gps, gps sale & gps coupons. Bookmark DealsOfAmerica.com ... Prices, GPS Coupons and/or gps promotions in each deal were active at the time ...
38. GPS-Planet.com Offering name-brand car and truck GPS units.