How do GPS know where are you

In big cities you can now select what GPS tool? TomTom, Magellan and Garmin gets into your eyes, and with the popularity of smart phones, everyone can have a GPS positioning system. But did you know how GPS works?

The global positioning system (GPS) is actually a satellite monitoring of terminology, there are currently 24 satellites around the Earth, first launched in 1978, 24 complete launch was in 1993, and formally put into use in 1995, the system cost $ 10.012 trillion, the annual maintenance costs are estimated at about $ 400 million. Each satellite weighed 2000 pounds and relies on solar power, around the Earth takes 11 hours and 58 minutes, one orbiting the Earth two weeks at 10600 miles above sea level (altitude).

When setting up a satellite system is because the United States wants to deploy military weapons, systems named NAVSTAR,2000 year, when President Clinton's GPS system is open to the world.

Any time your phone's GPS system will be received from the 4-12 satellite positioning, the satellite's orbit form a cage-like surround system via triangulation technology, your GPS device can tell you the exact location. For example, through the eyes of three satellites, using high-frequency, low-power radio signals at the speed of light, and then calculates the distance between the satellites with equipment, because they have a fixed orbit pattern, and the United States Naval Observatory atomic clock synchronization, this process generates an accurate position reading. But in order to more precisely, GPS systems typically grabs satellite signals, in particular need to determine altitude when.

As long as the GPS knows where you are, you can map routes, speed, and other location information, such as the other half of the Earth a place of sunrise and sunset. With the passage of time, the accuracy of GPS will be slightly affected by the Sun and the Moon, but United States Defense Council will regularly send updated data to the satellite correction. Vans case

Whether it is on foot, car, boat or air, GPS systems are very useful, and thank you for many applications to launch, GPS have bigger stage, most real life example of this is the Government access to relevant technology and sharing of traffic data to ease urban traffic problems. case iPhone Vans

Via mashable