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GCN : December 2013
12 GCN DECEMBER 2013 • GCN.COM [BrieFing] The Government Accountability Of ce said GPS has become "an invisible util- ity" underpinning many applications criti- cal to the nation's security and economy. A number of executive directives have mandated programs to detect and miti- gate accidental or malicious interference, but, "sectors' increasing dependency on GPS leaves them potentially vulnerable to disruptions," GAO concludes. The Transportation and Homeland Security departments have primary responsibility for ensuring the security of systems relying on GPS, but a lack of resources and cooperation has limited progress in identifying backup technologies in the last eight years. In its report, "GPS Disrup- tions: Efforts to Assess Risks to Critical Infrastructure and Coordinate Agency Ac- tions Should Be Enhanced," GAO recommends that DHS produce a more reliable assessment of the risks of GPS disruption together with metrics for the effectiveness of risk mitigation and that the two departments establish a formal agreement laying out roles and responsibilities. GPS is a satellite-based system providing precise timing signals that can also be used to determine position and for navigation. Timing functions are used widely in critical infrastructure, and trans- portation industries, particularly aviation and maritime, use GPS for navigation. Because it relies on radio signals, GPS is susceptible to natural interference from weather on Earth and in space, to ac- cidental interference from other devices and to intentional blocking or spoo ng. Disruptions to service have not been common. The U.S. Coast Guard, which elds reports of GPS problems, received 44 such reports in 2012. But reporting is not mandatory, and GAO noted that USCG's role is not widely known, so incidents could be underreported. GAO examined the use of GPS in four critical infrastructure sectors --- com- munications, energy, nancial services and transportation --- as well as DHS and DOT efforts at risk management. The communications and transportation industries are most reliant on the service, although the nancial services and energy sectors use its timing features to a lesser extent. DHS has produced a National Risk Estimate for GPS, released in 2012 for of cial use only. GAO criticized the report, saying it is incomplete and has limited usefulness because it does not meet the department's own guidance for risk management. DHS defended the study, saying that its scope was limited, that it ful lls its intended purposes and that it "suf ciently characterized the risk environment." GPS is the backbone for NextGen, the Federal Aviation Administration's next- generation air traf c control system, and because of its use for navigation DOT is the lead civilian agency for GPS reliability efforts. The department was charged in a 2004 national security directive with de- veloping backup capabilities for govern- ment and industry, with the assistance of DHS. An implementation plan for a national position, navigation and timing architecture has been released, and potential backup alternatives for FAA NextGen are being researched. Current navigational alternatives to GPS do not support NextGen capabilities, and FAA expects to make a decision by 2016 on a backup system. USCG is doing research to test alternative non-space-based sources of timing, NIST is researching the possibil- ity of using the nation's ber networks as an alternative, and DHS has commissioned a study of ways to detect and mitigate sources of disrup- tions. The Defense Advanced Research Projects Agency also is working on alternative navigation tools. But GAO found little progress had been made in identifying adequate backup technologies, due to a lack of staf ng and budget and to a lack of cooperation between the two lead de- partments. Roles in the effort have not been clearly de ned, and DOT sees its job as addressing only the needs of the transportation sector, leaving the rest to DHS. But DHS says that the terms of the directive put DOT in the lead position. DHS said that it will establish a formal, written agreement with DOT "that will clearly delineate roles and responsibili- ties" in developing GPS backup capabili- ties. But it noted that "the ability to fully implement agreed-upon shared tasks will be contingent on the availability of personnel and nancial resources." • GPS disruption could have a wide impact on US systems BY WILLIAM JACKSON NATIONAL OCEANIC AND ATMOSPHE4RIC ADMINISTRATION The constellation of GPS satellites provide precise timing and location data essential to much of the nation's critical infrastructure.