In 1998, United States Vice President Al Gore announced plans to upgrade GPS with two new civilian signals for enhanced user accuracy and reliability, particularly with respect to aviation safety, and in 2000 the United States Congress authorized the effort, referring to it as GPS III.
1998. - američki potpredsjednik Al Gore objavljuje planove nadogradnje GPS-a s dva nova civilna signala radi poboljšane korisničke preciznosti i pouzdanosti, posebice u odnosu na avijacijsku sigurnost a 2000. američki Kongres potvrđuje potporu koju naziva GPS III.