US efforts pointing to coherent, resilient PNT architecture

December 2, 2019  - By

DoT remarks follow China announcement on “comprehensive PNT”

The U.S. Department of Transportation “…is seeking the best solutions to ensure that America has a combination of  PNT [positioning, navigation and timing] systems which, when used together, will be difficult to disrupt” according to remarks made at a recently concluded conference.

Diana Furchtgott-Roth (Photo: USDOT)

Diana Furchtgott-Roth

Diana Furchtgott-Roth is the department’s Deputy Assistant Secretary for Research and Technology. She made the comments during a keynote address at the Royal Institute of Navigation’s annual conference in Edinburgh mid-November.

Trained as an economist, Furchtgott-Roth noted that Edinburgh was the home of Adam Smith who in the 1700s referred to the efficiency of free markets as an “invisible hand” guiding economies. She regularly referred to GPS as “the invisible hand” guiding individuals, transportation, and technologies across the globe.

Citing GPS as a “one of the great and heroic systems of our times,” she also acknowledged wide and generally unconscious reliance on GPS signals, and its vulnerabilities. “A lot of the work in research and technology at the Transportation Department…assumes the existence of GPS. It assumes that GPS will continue to work, sight unseen, without interference.”


A dedicated GPS-only receiver “sounds as outdated as a pager.”


While PNT is essential now, she said, it will be even more important in the future as it becomes essential for even more safety applications.

“Public confidence in these will be critical. People will not be comfortable getting into an automated vehicle or with platooning driverless trucks heading down the highway if they think that their invisible hand is not reliable and that their GPS might be spoofed.”

As part of this, development and adoption of a wide variety of space-based, terrestrial, and self-contained navigation sensors must be deployed and widely adopted. A dedicated GPS-only receiver, she said, “sounds as outdated as a pager.”

She also echoed the theme of protecting frequencies, toughening receivers, and augmenting GPS signals as a way of achieving greater PNT resilience.

The department let a contract in November for demonstration of 11 technologies that could serve as a GPS augmentation/backup system. Furchtgott-Roth said, “This effort will inform implementation of a system that by law is required to be terrestrial, wireless, have wide area coverage, be difficult to disrupt, and be capable of expansion to provide positioning and navigation services.”

Departing from her prepared script, she added, “The Department of Transportation hopes to come to a decision by next May. Then we will get together with the Defense Department and the Department of Homeland Security and chose a technology or combination of technologies… And then we hope that our Congress will allocate funds to purchase this equipment. Our top priorities are national and economic security. We cannot have GPS be a single point of failure for transport and other critical infrastructure.”

The United States published its National PNT Architecture Study in 2008 citing the need for an integrated and resilient approach. Despite its call for use of multiple phenomenologies and an implementation plan signed several years later little has been done as of yet now.

Furchtgott-Roth’s comments came roughly a month after a Chinese representative to a Stanford symposium that here nation was developing a national “comprehensive PNT” after the fashion of what was called for in the U.S.’s 2008 study.

Her prepared remarks are available here.