On 15 January the US Department of Transportation (USDOT) released the report to Congress entitled: Complementary Positioning, Navigation, and Timing (PNT) and GPS Backup Technologies Demonstration1.

USDOT’s Volpe National Transportation Systems Center (Volpe Center) conducted field demonstrations of candidate PNT technologies that could offer complementary service in the event of Global Positioning System (GPS) disruptions. The purpose of the demonstrations was to gather information on PNT technologies at a high Technology Readiness Level that can work in the absence of GPS.