gps

gps receiver comparison
650 gps treo
gps satellite navigation system
gps child locator
garmin forerunner 201 gps personal training device
motorcycle gps mount
garmin gps sales
marine gps navigation software
garmin gps 3
gps holux receiver usb
gps car video navigation
discount lowrance gps
tomtom gps navigator
avic car dvd gps mp3 n2 navigation pioneer
gps fish finder review
portable automotive gps
gps receiver serial
garmin gps map 76c
gps microsoft street and map
antenna gps receiver
nextel cell phone with gps
magellan blazer 12 gps
monarch gps receiver
gps truck tracking system
navman gps review
compare gps system
etrex gps
garmin gps handheld unit
magellan gps 3000 xl
gps product review
gps map satellite
canada gps map
rental car gps navigation
garmin gps 76c
wireless blue tooth gps receiver
gps laptop mapping software
blue tooth ipaq gps
tom tom gps navigator
track gps cell phone
gps hunting unit
3000 direction gps magellan use xl
gps based vehicle tracking
cell gps navigation phone
color gps magellan meridian receiver
cobra gps review
760 gps magellan roadmate
using map with gps
garmin street pilot gps
lowrance gps unit
c330 garmin gps receiver streetpilot
gps cell phone cingular
free gps tracking
portable car gps navigation system
portable gps navigator
lowrance 500 gps
sdio gps receiver
lowrance sonar gps
gps home motor navigation
automobile gps
alarm car gps gsm
garmin gps language odbiorniki pl
automotive gps
60 gps map
free gps map download garmin
car stereo with gps
toyota gps navigation system
map for gps handheld
gps software download
gps handhelds
adapt blue gps receiver tooth
800 gps magellan
gps mount
gps navigator system
microsoft gps
gps fixed mount
garmin gps 48
gps map software
device gps gps
portable gps receiver
magellan portable gps
hand held gps unit
handheld gps forum
gps israel map
gps iii navilock receiver sirf usb
gps lowrance map
lowrance ifinder go2 gps

The GPS or Global Positioning System is a global navigation 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.

The US military has developed the ability to locally deny GPS (and other navigation services) to hostile forces in a specific area of crisis without affecting the rest of the world or its own military systems. Such Navigation Warfare uses techniques such as local jamming to replace the blunt, world-wide degradation of civilian GPS service that SA represented.

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 author would have loved to have used GPS years ago in college. We had a class where we used maps and compasses. We were given precise coordinates and had to plot a course through woods and streams and swamps to find and sign in at specific latitude and longitude coordinates. Today, this sport, now called "geocaching", is a popular activity, particularly for outdoor hiking enthusiasts.

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.

GPS receivers calculate their current position (latitude, longitude, elevation), and the precise time, using the process of trilateration after measuring the distance to at least four satellites by comparing the satellites' coded time signal transmissions.

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 late 2005, the US government introduced the first in a series of new generation GPS staellites offering new capabilities. Chief among these is a second civilian GPS signal called L2C for greater accuracy and reliability.

One of biggest problems for GPS accuracy is that changing atmospheric conditions change the speed of the GPS signals unpredictably as they pass through the ionosphere. The effect is minimized when the satellite is directly overhead and becomes greater toward the horizon, as the satellite signals must travel through the greater "thickness" of the ionosphere as the angle increases. Once the receiver's rough location is known, an internal mathematical model can be used to estimate and correct for the error.

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.

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.

During the Gulf War, the shortage of military GPS units and the wide availability of civilian ones among personnel resulted in disabling the Selective Availability. In the 1990s the FAA started pressuring the military to turn off SA permanently. This would save the FAA millions of dollars every year in maintenance of their own, less accurate, radio navigation systems. The military resisted for most of the 1990s, but SA was eventually turned off in 2000 following an announcement by then US President Bill Clinton, allowing all users to enjoy nearly the same level of access.

More accurate GPS receivers are used these days in surveying to accurately locate boundaries, structures and so on.

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.

lowrance ifinder go2 gps online resources.
Site map