Global Positioning Satellite System has three parts that are both dependent and independent to one another. They are called segments and each segment has a hand in the basic processes such as data requesting, data transmitting, processing and retrieval or return. The three segments are the user segment, space segment and control segment. This delicate balance of monitoring and receiving data keeps the system in check.
The space segment contains the most cost amongst all the three segments. This segment contains the net of twenty four satellites that make a routine orbit around the planet, handling their own areas of responsibility. The satellites keep a distance of eleven thousand nautical miles from around each other to prevent bumping. Orbitting around the earth takes 12 hours each and each satellite is equipped with devices to keep each unit from bumping into each other. Bumping satellites are becoming more and more common due to the space debris floating in outer space.
The control segment consists of various ground stations that are placed on Earth. They are stationary locations that are responsible for handling various data that goes from satellite to each monitoring station. A master control station is located at Colorado, in the Schriever Air Force Base. Six other unstaffed stations located in Hawaii, Kwajalein, Diego Garcia in the Indian Ocean, Ascension Island in the Atlantic, Cape Canaveral in Florida and another one in Colorado make up the system. There are four other large ground antenna stations that send data and monitor the satellites themselves to make sure they don't go off in an unexpected manner.
The user segment are those that are being held by the people that use this system. They are called GPS receivers, as they receive data that is sent by the satellites and processed by the ground stations. There are at least a hundred of these models scattered around the world, from something as small as a wristwatch to those in a car. The smallest could weigh as little as an ounce.
As the user sends a request, this is handled by the space segment. The space segment sends back data according to the location of the user which explains the fast response time. The monitoring stations, meanwhile, make sure that the satellites stay in order to prevent any accidents. All their collected data is sent to the master control station for processing or storage. The ground antenna from the master control station then sends needed data for the space segment to adjust in case it is needed.