An intro to GPS

First , What's the meaning of GPS ?
  It's meaning Global Positioning System .

    This system is based on a system of satellites ,Revolves around the Earth and works on solar energy and the spin rate of two complete cycles per day.The orbits are arranged so you can see 4 satellites in the sky at any time and from any point on Earth's surface.

     GPS receiver determine the location of these satellites and calculate the distance between them and the earth, and take advantage of these data to infer the site of the future and thus determine your coordinates on the surface of the earth. 

     Knowing the distance from a satellite, you will be on the surface of the ball with a diameter of the amount of this distance , Knowing the distance from the second satellite we will  have 2 balls intersect in a circle,  And your site will be one of the points the Circumference of this circuit.

     Gps receiver is depend on radio waves to calculate the distance from the satellites and calculates the duration of the these waves to cross the distance.

     Boats and ships  uses it to locate it's location and Taxis companies too .