WASHINGTON — As jamming and disruptions to the nation’s positioning, navigation and timing satellites become more commonplace, the federal agency in charge of coordinating a national effort to protect critical infrastructure cannot ensure that “essential” operations would continue during an outage, according to a new report.

GPS “has become an invisible utility that users do not realize underpins their applications, leaving sectors potentially vulnerable to GPS disruptions,” a Nov. 6 report from the Government Accountability Office (GAO) read.

Industry officials have said the proliferation of GPS jamming devices is creating a market for countermeasures, both in the defense and commercial sectors. In a speech at the annual Air Force Association conference Sept. 17, Gen. William Shelton, commander of Air Force Space Command, which operates the 30-plus satellite GPS constellation, highlighted jamming as an increasingly common problem. 

But too often, the GAO report said, GPS outages are viewed as “low risk.”

In “GPS Disruptions: Efforts to Assess Risks to Critical Infrastructure and Coordinate Agency Actions Should Be Enhanced,” GAO officials said the Department of Homeland Security has underestimated the services that rely on GPS. Additionally, the Homeland Security and Transportation departments have made limited progress developing backup plans for GPS disruptions. Those plans are required as part of a 2004 presidential directive. 

The Transportation Department has been researching three potential GPS backup solutions for the satellite-enabled Next Generation Air Transportation System and expects to make a decision by 2016, the report said. The Homeland Security Department, through the U.S. Coast Guard, has been testing nonspace-based alternative to GPS’s precision timing service. The National Institute of Standards and Technology, meanwhile, is leading research on using fiber networks for precision timing. 

In the meantime, the GAO said the Homeland Security Department had not measured how effective the nation’s backup plans would be in the event of a disruption.

“The inability to mitigate the negative effects of a GPS disruption, especially a longer-term disruption, could potentially lead to loss of life or billions in economic losses,” the report said.

In one example, U.S. Coast Guard officials told the GAO that mariners accustomed to relying on GPS might no longer have the skills to use legacy systems, a move that could translate to millions of dollars in losses, the report said.

In another example, numerous alarms sounded on a ship’s bridge during a GPS disruption test, signifying the failure of different systems. The GAO said the test raised concerns that GPS signal loss could lead to hazardous conditions for mariners.

The report focused largely on nonmilitary uses of GPS.

The GAO recommended Homeland Security collect threat and vulnerability data for critical infrastructure. The watchdog agency also questioned whether government officials had enough expertise to understand the full scope of GPS vulnerabilities within certain sectors. 

“High-impact events, such as extreme solar storms, spoofing, and high-power jammers — which can impact a larger geographic area, or can have larger consequences in terms of safety, loss of life, and economic loss — are perceived as low probability,” the report said.

In a response, Jim Crumpacker, director of the Homeland Security Department’s GAO liaison office, disagreed saying government and nongovernmental entities accurately characterized the risks.

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Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...