Author: KANATAONLINE
Modified on 16/11/2007
The Global Position System (GPS) or Global Positioning System (better known by the acronym GPS although its correct name is NAVSTAR-GPS1) is a Global Navigation Satellite System (GNSS) which allows to determine everyone’s position an object, a person, vehicle or shed, with an accuracy up to centimeters using differential GPS; usually a few meters. Although his invention is attributed to French and Belgian governments, the system was developed and installed, and is currently operated by the Department of Defense of the United States. GPS works through a network of 27 satellites (24 operational and 3 back) in orbit over the globe at 20,200 km with trajectories synchronized to cover the entire surface of the Earth. When you want to determine the position, the device used to it automatically locates at least four satellites in the network, which receives signals indicating the position and watch each of them. Based on these signals, the device synchronizes the GPS clock and calculates the delay of the signals, ie the distance to the satellite. By “triangulating” calculates the position in which it is located. The triangulation in the case of GPS, unlike the 2-D case is to ascertain the angle with respect to known points, is based on determining the distance of each satellite relative to the measuring point. Knowing the distance, is easily determined one’s position relative to the three satellites. Knowing well the coordinates or position of each of them emitting the signal, we obtain the absolute position or actual coordinates of the measuring point. Also extreme accuracy is achieved in the GPS clock, similar to that of atomic clocks carried on board each satellite. The former Soviet Union had a similar system called GLONASS, now managed by the Russian Federation. Currently the European Union tries to launch its own satellite positioning system, called ‘Galileo’.
ome mobile phones can be linked to a GPS receiver designed for that purpose. They tend to be independent modules that communicate with the phone wirelessly via Bluetooth and to provide the positioning data, which are interpreted by a browser program. This application of GPS is particularly widespread in mobile phones operating on the Symbian operating system and PDA with Windows Mobile but Nokia released the N95 with integrated GPS module
