Official US Government Icon

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.

Secure Site Icon

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

The latest general information on the Coronavirus Disease 2019 (COVID-19) is available on For USDOT specific COVID-19 resources, please visit our page.

GPS Backup Demonstration: National Defense Authorization Act 2018, Section 1606

Accurate sources of Positioning, Navigation, and Timing (PNT) information support critical infrastructure in the transportation sector and are essential for national security. The primary and most recognizable service supporting critical infrastructure is the Global Positioning System (GPS). However, because GPS relies on signals broadcast from the constellation, its signals are low power at the receiver and thus opens vulnerabilities to intentional and unintentional disruption.

U.S. DOT's Office of the Assistant Secretary for Research and Technology (OST-R)  conducted field demonstrations of candidate PNT technologies that could offer complementary service in the event of GPS disruptions. The demonstrations focused on technologies at a high Technical Readiness Level (TRL) and that can work in the absence of GPS. This effort stems from the 2018 National Defense Authorization Act (NDAA) Section 1606, which directed the Secretary of Defense, the Secretary of Transportation, and the Secretary of Homeland Security to jointly develop a plan for demonstrating PNT capabilities in the absence of GPS.

The Government, through a competitive acquisition process, selected 11 candidate technologies to demonstrate Position and Timing capabilities in the absence of GPS over two demonstration sites. Five technology vendors demonstrated at Joint Base Cape Cod (JBCC) and six technology vendors demonstrates at NASA Langley (LaRC). The Government ran nine possible scenarios, allowing each vendor to select which scenario(s) it would like participate.

Last updated: Tuesday, May 5, 2020