In 1997 the President’s Commission on Critical Infrastructure Protection, which was charged with examining threats to our national security, recommended an assessment be made of the vulnerability of the U.S. transportation infrastructure if it had to rely on GPS. Subsequently, the DOT was directed to assess the “risks to civilian users of GPS-based systems, with a view to basing decisions on the ultimate architecture of the modernized National Airspace System.” In turn, the DOT assigned this task to its highly respected Volpe Transportation Systems Center in Cambridge, Mass.
The Volpe study, released last month after lengthy internal delays, suggests that sole-means GPS may be much further away than previously believed. “There is a growing awareness within the transportation community that the safety and economic risks associated with loss or degradation of the GPS signal have been underestimated,” the report states, and to ensure optimum safety it advocates the “use of backup systems and procedures to GPS in applications where the consequences of losing GPS are unacceptable.”
