SAASM

SAASM

An SAASM, for "Selective Availability / Anti-Spoofing Module", is used by military Global Positioning System receivers to allow decryption of precision GPS coordinates, while the accuracy of civilian GPS receivers may be reduced by the US military through Selective Availability.http://www.symmttm.com/pdf/Gps/an_saasm.pdf] However, the US Presidential directive instructing the discontinuation of Selective Availability, along with the directive that no future GPS programs will include selective availability makes any changes to SA unlikely.

SAASM allows satellite authentication, over-the-air rekeying, and contingency recovery. Those features are not available with the similar, but older PPS-SM system. PPS-SM systems require periodic updates with a classified "Red Key" that may only be transmitted by secure means (such as physically taking the receiver to a secure facility for rekeying or having a trusted courier deliver a paper tape with a new key to the receiver, after which that paper tape must be destroyed). SAASM systems can be updated with an encrypted "Black Key" that may be transmitted over unclassified channels. All military receivers that will be newly-deployed after the end of September 2006 must use SAASM..

SAASM does not provide any additional anti-jam capability because it uses the exact same signal-in-space as current GPS signals (power and modulation). Future GPS upgrades, such as M-Code, will provide anti-jam capabilities.

SAASM hardware modules are covered with a sophisticated anti-tampering coating, to deter analysis of their internal operation.

The next generation military signal for GPS, called M-code, will be launched on IIR-M and IIF satellites beginning in 2005. A complete constellation of 18 satellites with M-code capability is planned for 2016.

References

[http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=21878 GPSworld.com article "Saving SAASM"] by Robert Huffman (Webpage, January 2006)


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Defense Advanced GPS Receiver — The Defense Advanced GPS Receiver (DAGR) The Defense Advanced GPS Receiver (DAGR; colloquially, dagger ) is a handheld GPS receiver used by the United States Department of Defense and select foreign military services. It is a military grade, dual …   Wikipedia

  • AGM-154 Joint Standoff Weapon — The AGM 154 Joint Standoff Weapon (JSOW) is the product of a joint venture between the United States Navy and Air Force to deploy a standardized medium range precision guided weapon, especially for engagement of defended targets at ranges outside …   Wikipedia

  • Paveway IV — The Raytheon Paveway IV is a new generation dual mode GPS/INS and laser guided bomb for use by military aircraft. It is the latest iteration of Raytheon s popular Paveway series.The weapon is a guidance kit based on the existing Enhanced Paveway… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”