Origins, Evolution, and Future of Satellite Navigation

The Global Positioning System (GPS or NAVSTAR) has been called the most significant civil spin-off of the cold war. It evolved from technology efforts in the Navy and in the Air Force but was almost canceled before gaining approval by the Department of Defense. While it offers phenomenal accuracy (centimeters for landing aircraft), it still requires some expansions to satisfy integrity, continuity, and availability requirements. Most of all, for this system to be formally accepted (and certified) internationally, the world will need greater confidence in commitments by the U.S. and greater participation by the world community. (Author)