Global Positioning System Global Positioning System or GPS is better known as "a satellite based radionavigational system developed and operated by the U.S. Department of Defense (DOD). Global positioning system permits land, sea, and airborne users to determine their three-dimensional position, velocity, and time twenty-four hours a day, in all weather, anywhere in the world with a precise and accuracy far better than other radionavigation systems available today or in the foreseeable future." (Navcen) The Global Positioning System was designed for two services. One being, the Standard Positioning System and the other being the Precise Positioning