The 2017 National Defense Authorization Act (NDAA) mandated a study “to assess and identify the technology-neutral requirements to backup and complement the posi-tioning, navigation, and timing [PNT] capabilities of the Global Positioning System [GPS] for national security and critical infrastructure.”

Having accurate PNT is essential for critical infrastructures across the country, and currently GPS is the primary source of PNT information for many applications. However, GPS signals are susceptible to both unintentional and intentional disruption, thus leaving critical infrastructure vulnerable. Because of the essential need for precise positioning or timing in many critical-infrastructure sectors, the Homeland Security Operational Analysis Center (HSOAC) was tasked to provide the U.S. Department of Homeland Security (DHS) with a study of the costs and benefits of proposed new PNT systems for the various types of critical infrastructure.