Monday, 1 October 2012

Why is it said that the 'Global Positioning System'(GPS) is helped to how the exact position on earth?

GPS (Global Positioning System) is a system which shows the exact position in anywhere,anytime in the Earth.It works with a help of a number of GPS satellites orbiting in the earth. The GPS device is like this:

A GPS navigation device is a device that receives GPS signals for the purpose of determining the device's current location on Earth. GPS devices provide latitude and longitude information. GPS devices are used in military, aviation, marine and consumer product applications.
GPS devices may also have additional capabilities such as:
  • containing all types of maps, like streets maps, which may be displayed in human readable format via text or in a graphical format
  • providing suggested directions to a human in charge of a vehicle or vessel via text or speech
  • providing directions directly to an autonomous vehicle such as a robotic probe
  • providing information on traffic conditions (either via historical or real time data) and suggesting alternative directions
  • providing information on nearby amenities such as restaurants, fueling stations, etc.
Each satellites is equipped with precise clocks that keeps an accurate time.These time signals are  transmitted with other parameters,to the receiver or the navigational device.The receiver detects the signals from three satellites,by doing some mathematical calculations, its locations is accurately  determined.By getting the information from a fourth satellites,it is able to give the time also.Thus,the navigational device sees four satellites at a time.