A conditional approval of LightSquared’s use of the mobile satellite spectrum in 2011 put GPS signals at risk of dangerous interference—but Congress has the power to protect GPS from present and future threats, AOPA President Craig Fuller told a House subcommittee Feb. 8.
The House Transportation and Infrastructure Committee’s aviation subcommittee’s hearing on the importance of GPS as a critical part of transportation infrastructure allowed Fuller to make recommendations on new protections that are needed to preserve the system’s safety-critical role in the National Airspace System.
In today’s society, GPS is both critical and vulnerable, Fuller explained: Pilots rely on satellite-based systems for everything from en route navigation to precision approaches. “Just as surface highways provide for commercial and personal transportation around the nation, so GPS ‘highways’ in the sky allow for the efficient movement of people and goods via general aviation aircraft,” he said in testimony. “And just as the integrity and access to our surface infrastructure must be protected, so must the reliability and accessibility of our airborne infrastructure.”
Interference with GPS signals—which, as the subcommittee’s briefing memo noted, travel 12,500 miles from space to the receivers and are comparatively weak—could jeopardize use of the foundational technology in airspace modernization efforts, Fuller said. And to make matters worse, no formal backup is in place in case of GPS system shutdown or interference.
“Access to the GPS system is also vulnerable to interference from changing uses of the broadcast spectrum,” Fuller said. “As recent events showed, powerful ground-based transmitters using spectrum adjacent to that designated for GPS are one potential source of interference. But as the demand for bandwidth continues to grow and new technologies are developed, the potential for interference will also continue to expand.” He urged the subcommittee to protect GPS from potential new threats as well as existing ones.
While current policy and practice offer protection to GPS, further protections are needed, Fuller added: A “clear statement of the need and intent to protect the system from a wide range of harmful actions would be an effective starting point.” New protections will require extensive cross-agency and user collaboration, he said, including input from the FAA, Federal Communications Commission, Department of Defense, Department of Homeland Security, Department of Agriculture, and others.
Other witnesses included Department of Transportation Deputy Secretary John Porcari, who testified about the benefits of NextGen and the role of GPS in other important services. Subcommittee Chairman Tom Petri (R-Wis.) later underscored the importance of GPS to aviation and the broader economy in a media release.
“Efforts must be made to ensure aviation safety and efficiency benefits made possible by GPS are preserved,” Petri said. “I was pleased to hear Deputy Secretary Porcari’s announcement this morning of the proactive plan the Department will pursue to protect GPS safety and efficiency benefits. We will work with the aviation community, the Department of Transportation, and our colleagues to find the best path forward to achieve that goal.”
