In the
global positioning system (
GPS), Selective Availability refers to the decreased accuracy of the civilian band GPS. Selective Availability can be set to vary between 10 and 200
meters, although it has normally been set at about 50 meters.
Comparison of Accuracy with and without Selective Availabilty
Collection 95% 95%
Hours with SA without SA
24 45.0 m 6.3 m
12 60.7 m 7.9 m
6.5 48.3 m 4.5 m
Data collected by NOAA in spring 2000.
On May 1, 2000, SA was removed from GPS by Executive Order.