Selective availability (SA)

Selective Availability (SA)

Selective Availability (SA) is a satellite technology that once allowed the Department of Defense (DOD) to intentionally introduce clock and ephemeris errors into the GPS satellite signals in order to degrade the accuracy of civilian GPS devices. The primary reason for this was to enhance national security by preventing potential enemies from using GPS for accurate targeting purposes. However, SA was discontinued in 2000 due to advancements in military technology as well as increased civilian reliance on GPS. SA’s discontinuation allowed civilian GPS devices to achieve improved accuracy, which in turn has led to increased usage of GPS in everyday life and a variety of industries.