GPS Tracking
The Global Positioning System (GPS) or Global Positioning System (better known by the acronym GPS, although its correct name is NAVSTAR-GPS [1]) is a global navigation satellite system (GNSS) for determining worldwide the position of an object, person, vehicle or a ship, 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 above the earth, at 20,200 km, with trajectories synchronized to cover the entire surface of the Earth. When you want to determine the position, the receiver used to it automatically locates at least three satellites in the network, which receives signals indicating the position and watches each of them. Based on these signals, the device synchronizes the GPS clock and calculates the delay of the signals, i.e. the distance to the satellite. By "triangulating" it 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 and it is based on determining the distance of each satellite relative to the measuring point. Knowing the distance is easily determined by 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 ma....
Currently the EU is developing its own satellite positioning system, Galileo.
Space segment
* Satellites in the constellation,24 (4 x 6 orbits)
or Altitude: 20,200 km
or Period: 11 h 56 min (12 hours sider)
or Inclination: 55 degrees (relative to terrestrial Ecuador).
or Life: 7.5 years
* Control Segment (ground station)
or Main Station: 1 land or antenna: 4
or station monitors (monitoring): 5
* RF Signal
or carrier frequency:
+ Civil - 1575.42 MHz (L1). Use the estimated acquisition code (C / A).
+ Military - 1227.60 MHz (L2). Use the Precision Code (P) encryption.
# Level of signal strength: -160 dBW (surface soil).
# Polarization: circular right-handed.
* Accuracy
or position: approximately 15 m (95%)
or Time: 1 ns
* Scope: Global
* User Capacity: Unlimited
* Coordinate system:
or World Geodetic System 1984 (WGS84).
or Earth-Centered, fixed.
* Integrity: notification time 15 minutes or more. NOT ENOUGH FOR CIVIL AVIATION.
* Availability: 24 satellites - 70% and 21 satellites - 98% NOT ENOUGH AS A PRIMARY NAVIGATION.
Today, there are many different areas of using the GPS system. It is useful and helpful advice in every car, aero plain, ship, bicycle or mobile phone. Therefore, its usage is very spread.For More Information Please visit. http://www.gps-teknik.se/