Selective Availability
Selective Availability (SA) was an intentional degradation of public GPS signals implemented for national security reasons. At the direction of the President, SA was discontinued in May 2000 to make GPS more responsive to civil and commercial users worldwide. The U.S. Government has no intent to use SA again.
In September 2007, the U.S. Government announced its decision to procure the future generation of GPS satellites, known as GPS III, without the SA feature. Doing this will make the policy decision of 2000 permanent and eliminate a source of uncertainty in GPS performance that has been of concern to civil GPS users worldwide for some time.
Information Regarding the September 2007 Decision
- White House Press Statement
- Department of Defense News Release
- Remarks by the Secretary of Transportation at ICAO Assembly
Information Released in 2001 and 2003
Information Regarding the May 2000 Decision
- Frequently Asked Questions about Selective Availability
- Statement by the President
- White House Fact Sheet
- Statement by the Secretary of Commerce
- Examples of Civilian Benefits from Discontinuing Selective Availability
- Transcript of White House Press Conference Featuring Remarks by OSTP, DOD, DOT, and DOC
- Remarks by the NASA Administrator at GNSS 2000 Conference
- Data from the First Week without Selective Availability