Transportation Department seeks GPS alternatives to fortify US’s position, navigation and timing system

The Department of Transportation is on the hunt for alternatives to GPS to better complement and support the nation’s transportation system with reliable position, navigation and timing (PNT) services.

The department’s John A. Volpe National Transportation Systems Center issued a request for information to identify capable vendors to participate in field tests of “very high technical readiness level” complementary PNT systems.

Specifically, the RFI seeks “technology capable of providing critical infrastructure users and operators positioning and/or timing information that is derived independently from Global Navigation Satellite Systems (GNSS).”

Much of the nation’s critical infrastructure, like the transportation system, depends on position, navigation and timing methodologies. While there are many PNT systems and uses, GPS is far and away the most popular.

However, as the RFI explains, “because GPS relies on signals broadcast from satellites in medium Earth orbit (MEO), signal strength at the receiver is low and thus vulnerable to intentional and unintentional disruptions.”

DOT was called on in a 2020 executive order to lead the government’s efforts to enhance PNT resilience.

The eventual field tests are meant to “characterize the capabilities and limitations of such technologies to provide PNT information that meet critical infrastructure needs when GPS service is not available and/or degraded due [to] environmental, unintentional, and/or intentional disruptions. This deployment is intended to test these technologies against CI-relevant requirements in order to gain confidence in performance and foster user adoption.”

DOT’s Volpe Center in 2020 held field demonstrations of GPS alternatives, which resulted in a report on those systems. However, that event did not ” test the technology performance against stringent CI requirements and needs including resiliency to cybersecurity threats (e.g. jamming and spoofing of PNT signals).” It also allowed the participation of technologies of lesser maturity, according to the RFI.

Transportation will accept responses to the RFI through Oct. 10.

The Department of Defense is also working on alternatives to GPS in case the system isn’t available for troops and their weapon systems. In March, Defense CIO John Sherman said with global tensions rising in ways reminiscent of the world wars, the DOD needs to quickly identify and adopt alternatives to GPS ahead of a potential conflict with great power adversaries because it will be those nations’ first target in a modern war.