What is GPS?
The Global Positioning System (GPS) is a satellite-based navigation system
made up of a network of 24 satellites placed into orbit by the Department
of Defense. GPS was originally intended for military applications, but in the 1980s,
the government made the system available for civilian use. GPS works in any weather
conditions, anywhere in the world, 24 hours a day. There are no subscription fees
or setup charges to use GPS.
How it works
GPS satellites circle the earth twice a day in a very precise orbit and transmit
signal information to earth. GPS receivers take this information and use triangulation
to calculate the user's exact location. Essentially, the GPS receiver compares the time
a signal was transmitted by a satellite with the time it was received. The time difference
tells the GPS receiver how far away the satellite is. Now, with distance measurements
from a few more satellites, the receiver can determine the user's position and display it
on the unit's electronic map.
A GPS receiver must be locked on to the signal of at least three satellites to
calculate a 2D position (latitude and longitude) and track movement.
With four or more satellites in view, the receiver can determine the user's 3D
position (latitude, longitude and altitude). Once the user's position has been determined,
the GPS unit can calculate other information, such as speed, bearing, track, trip distance,
distance to destination, sunrise and sunset time and more.
Today's GPS receivers are extremely accurate, thanks to their parallel multi-channel design.
12 parallel channel receivers are quick to lock onto satellites when first turned on
and they maintain strong locks, even in dense foliage or urban settings with tall buildings.
Certain atmospheric factors and other sources of error can affect the accuracy of GPS receivers.
GPS receivers are accurate to within 15 meters on average.
Newer GPS receivers with WAAS (Wide Area Augmentation System) capability
can improve accuracy to less than three meters on average. No additional equipment or fees
are required to take advantage of WAAS. Users can also get better accuracy with Differential GPS (DGPS), which corrects GPS
signals to within an average of three to five meters. This system consists of a network of towers that receive GPS signals and
transmit a corrected signal by transmitters. In order to get the corrected signal, users must have a differential receiver and antenna
in addition to their GPS.
A GPS system comes with a “panic” button. When this button is pressed an operator
at the GPS carrier can listen in on the conversation and either help you out or alert the
authorities. This will keep you safe in case of accidents or hi-jacks.
Your car will never loose your car at a football match or mall.
The GPS service will track the car for you and send its lights flashing.
If your vehicle is ever stolen the GPS system will track the vehicle and
the authorities will be able to get it back in no time.
A GPS system in a car, boat, plane or haversack will ensure that you are never lost.
A GPS system streamlines supply chains and truck movements. The system
can track goods at any point of time and accurately predict when goods will reach their destination.
GPS systems are used to detect structural problems in buildings and roads and to predict disasters like earthquakes and so on. The scientific
applications of a GPS system are many.
A GPS system can be used to locate a lost child, pet or family. The device is quite small and is like a watch or button on a collar.
A GPS is a great exercise monitor and will help you keep track of your speed and so on.