Error analysis for the Global Positioning System: Difference between revisions

Revision as of 09:56, 17 June 2011

Revision as of 03:55, 19 June 2011

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Some countries allow the use of GPS repeaters to allow the reception of GPS signals indoors and in obscured locations; however, under EU and UK laws, the use of these is prohibited as the signals can cause interference to other GPS receivers that receive data from both GPS satellites and the repeater.

Due to the potential for both natural and man-made noise, numerous techniques continue to be developed to deal with the interference. The first is to not rely on GPS as a sole source. According to John Ruley, "[[Instrument flight rules|IFR]] pilots should have a fallback plan in case of a GPS malfunction".<ref>Ruley, John. AVweb. [http://www.avweb.com/news/avionics/182754-1.html GPS jamming]. February 12, 2003.</ref> [[RAIM|Receiver Autonomous Integrity Monitoring]] (RAIM) is a feature included in some receivers, designed to provide a warning to the user if jamming or another problem is detected. The U.S. military has also deployed since 2004 their [[SAASM|Selective Availability / Anti-Spoofing Module]] (SAASM) in the [[Defense Advanced GPS Receiver]] (DAGR).<ref>[https://rdit.army.mil/GPS/CustomContent/gps/ue/dagr.html US Army DAGR page]</ref> In demonstration videos the DAGR was shown to detect jamming and maintain its lock on the encrypted GPS signals during interference which caused civilian receivers to lose lock.

== See also ==