Date Added: Jul 2012
The Global Positioning System (GPS) is a satellite-based radio navigation system made up of a network of 24 satellites placed in an orbit by the US Department of Defense. GPS was originally intended for military applications, but now it is freely available to all. For anyone with a GPS receiver, the system will provide location and time. GPS provides accurate location and time information for an unlimited number of people in all weather, day and night, anywhere in the world. The GPS is made up of three parts: satellites orbiting the Earth; control and monitoring stations on Earth; and the GPS receivers owned by users. GPS satellites broadcast signals from space that are picked up and identified by GPS receivers.