What is “SELECTIVE AVAILABILITY”?
“SELECTIVE AVAILABILITY” (abbr.SA )is the artificial adulteration of the sent GPS signal for the civilian user. SA sets the theoretical accuracy from 200 m up. Since 01.05.00 ist “SELECTIVE AVAILABILITY” disconnected and now the full performance ability of the receiver is available to every GPS user.
In general civilian (not military) GPS can provide position information with an error of less than 25 meters, and velocity information with an error of less that 5 meters per second. The US Government had originally activated what was known as Selective Availability (SA) to maintain optimum military effectiveness. Selective availability inserts random errors into the timing and ephemeris information broadcast by the satellites, which reduces GPS SPS code accuracy to between 25 and 100 meters. Luckily for us, Selective Availability (SA) was switched off on May 2nd 2000. [Back to top] – GPS Availability – March 21, 2003 The United States Government recognizes that GPS plays a key role around the world as part of the global information infrastructure and takes seriously the responsibility to provide the best possible service to civil and commercial users worldwide. This is as true in times of conflict as it is in times of peace. The U.S. Government also maintains the capability to prevent
