The Government Accountability Office (GAO) was asked to review the effects of Global Positioning System (GPS) disruptions on the nation’s critical infrastructure. GAO examined: (a) the extent to which the U.S. Department of Homeland Security (DHS) has assessed the risks and potential effects of GPS disruptions on critical infrastructure; (b) the extent to which the U.S. Department of Transportation and DHS have developed backup strategies to mitigate GPS disruptions; and (c) the best strategies that selected critical infrastructure sectors should employ to mitigate GPS disruptions and any related challenges.
http://www.gao.gov/assets/660/658792.pdf