Inside GNSS: The PNT T.A.P. (Toughening, Augmenting, Protecting) Dance

One hundred days into the administration and the federal civil service crew has set the stage for the Biden team on the tough Positioning, Navigation, and Timing (PNT) issues they face: the Ligado debacle, interference concerns and a troubling lack of system redundancy or resiliency.

“With the stroke of a pen to allow the sale of such multi-element antennas, companies will produce them. Users could add them on military or civilian ships, airplanes, trucks and anywhere else where we could encounter a spoofing or jamming threat to productivity, safety, or general usage.”

Brad Parkinson, 1st Vice-Chair, National PNT Advisory Board

Reports indicate that the Department of Transportation (DOT)’s new Acting Assistant Secretary for Research and Technology (OST-R), Dr. Robert Hampshire, an electrical engineer, is a quick study who “gets” it. Hampshire will also serve as the co-chair of the Executive Steering Group of the National Executive Committee for Space-Based PNT. Now that he’s been educated on the current issues, what’s next?

Complementary Augmentation

Speaking of tim(ing), PNT augmentation also ranks high on DOT’s dance card. Van Dyke elaborates, “Augment is the complementary PNT aspect: what other tech can you integrate and take advantage of to use for positioning or timing functions in the absence of GPS, such as physically impeded environments indoors or underground or electronically impeded environments such as jamming or spoofing.”

DOT’s Volpe Center, which falls under the OST-R Assistant Secretary, selected 11 candidate technical readiness level (TRL)-qualified vendors for demos of various technologies. The resultant January 2021 report contained four principal findings.

• All TRL-qualified vendors (TRL 6 or higher) demonstrated some PNT performance of value.

• Only one, NextNav LLC, based in Sunnyvale California, demonstrated PNT performance in all use case scenarios. These use cases were: timing performance, positioning performance, timing-terrestrial broadcast; PNT-terrestrial broadcast; timing-broadcast; and PNT broadcast. NextNav’s Metropolitan Beacon System (MBS) geolocation platform, a multilateration 2D terrestrial-based P&T synchronized network of transmitters which revert to non-sat cesium clock or time-over-fiber timing sources in GPS-denied environments, came out on top.

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