Providing a Resilient Timing and UTC Service Using eLoran in the United States

Abstract

More and more systems are becoming solely dependent on GPS or other Global Navigation Satellite Systems (GNSS) for their precise position, timing, and frequency information. Along with this explosive growth comes an increasing awareness of GNSS vulnerabilities such as interference, jamming, and spoofing. eLoran is a high-power, low-frequency, ground-wave radio broadcast system, capable of providing 10-meter positioning accuracy, Stratum-1 frequency distribution, and UTC timing well within 1 μs across very large areas (1,000 mi). Application of differential corrections for timing further improves the accuracy to better than 100 ns. eLoran is a proven technology, well established for providing services very similar to those delivered by GNSS, with characteristics and failure modes that are complementary to GNSS. This paper discusses the general concept of eLoran timing and UTC distribution, and the current prototype service. It highlights plans for an initial four-station CONUS-wide timing service, which can be expanded to provide increased coverage and redundancy and deeper penetration into buildings. Additional stations enable positioning and navigation services. Copyright © 2017 Institute of Navigation