Session A1: Alternatives, Backups, Complements to GNSS

Time Transfer Performance of the Broadcast Positioning System™ (BPS™)
Tariq I. Mondal, National Association of Broadcasters; Jeffrey A. Sherman, National Institute of Standards and Technology; David A. Howe, University of Colorado and National Institute of Standards and Technology
Location: Beacon A

The Global Positioning System (GPS) is the most prevalent Global Navigation Satellite System (GNSS) that provides Position, Navigation, and Timing (PNT). GNSS vulnerability is well-known, and the search continues to find an independent system that can provide PNT services with comparable accuracy and precision, low user cost, and diverse coverage. NAB has developed and demonstrated a terrestrial PNT solution, known as the Broadcast Positioning System (BPS™), that uses existing NextGen TV (also known as ATSC 3.0 standard) transmission facilities to broadcast ns-level time. We investigate how accurately and reliably the ATSC 3.0 communications frames carrying BPS information function as time-reference beacons. This paper focuses on the BPS time transfer test results and stability using KWGN TV station in Denver and the NIST facilities in Boulder and Fort Collins, Colorado.
BPS time transfer stability is studied using signal from a live TV station and two baselines, one exceeding 100km. We show that the ns-level timing of BPS can support PNT services comparable to GPS or other GNSS. This is done using a BPS signal observed in common view at two different locations. After adjusting for the common sources of errors, it is observed that the stability of BPS time transfer is comparable to or better than GNSS, making BPS a viable complementary PNT solution when GNSS is unavailable.
BPS related blogs and NAB BEITC Proceedings papers are freely available at https://nab.org/bps/.