The GPS consists of three major segments: 1) Space Segment is composed of 24 to 32 satellites circulating around Earth orbit. 2) Control Segment is composed of ground control stations and shared antennas. 3) User Segment is represented by GPS devices. 1 - Each Satellite broadcast radio signals with their location, position and specific time. GPS radio signal travels at light speed, nearly 300,000 km/h. 2 - Quadcopter GPS Sensor receives radio signals, observing their exact time of arrival and use these data to calculate its distance from each satellite it can see. 3 - When the Quad GPS Sensor gets its distance from at least four satellites, it uses geometry to define its exact location on Earth.