Bradford Parkinson, professor of aeronautics and astronautics at Stanford University, conceived the present satellite-based system in the early 1960s and developed it in conjunction with the U.S. Air Force.
Bradford Parkinson, profesor aeronautike i astronautike na Sveučilištu u Stanfordu, osmislio je današnji satelitski sustav u ranim 1960-ima i razvio ga zajedno s Ratnim zrakoplovstvom SAD-a.