[SatNews] Its civil and recreational use has proliferated since 2000 when President Clinton ended Selective Availability, and the service that the GPS satellite constellation provides has for many become part of everyday life.
SSTL has faced increasing challenges as well as competition from other Global Navigation Satellite System (GNSS) systems around the world. In a time when U.S. government departments are operating on tight budgets, but demand for GPS data is increasing, future GPS satellites will need to be able to do more for less. They must also continue to fulfill essential requirements such as improved accuracy, interoperability with other GNSS systems, anti-jamming, and other signal security capabilities.
Progress has been made to modernize the system since Congress authorized these efforts in 2000, and the first GPS III satellites are due to begin service in 2015. This is a long concept-to-launch time (and one that has already been subject to delay), meaning that by the time the new satellites reach orbit, they will already be flying outdated technology. Various studies have also identified areas where delivery of subsets of GPS signal data would benefit the GPS military, civil, and commercial user communities.