Enhanced Loran for Timing and Frequency

Kevin Carroll, Tom Celano, Casey Biggs, and Gordon K. Weeks Jr.

Abstract:	The U. S Coast Guard (USCG) and Federal Aviation Administration (FAA) are cooperating in an effort to define and analyze the performance of a new Enhanced Loran system as a backup for GPS provided positioning, navigation and timing and frequency recovery services. The Loran Accuracy Performance Panel (LORAPP) is specifically addressing the critical infrastructure requirements of the frequency and timing communities. The USCG chaired LORAPP is spearheading the research and a proof-of-concept demonstration to determine the ability of an Enhanced Loran service to meet precision timing/frequency user’s needs. This paper examines the critical operational requirements centered on providing precise timing (sub 100 nanoseconds) and frequency stability (minimum of 10-12). The paper discusses how the uses of common-view techniques along with Differential Loran messages allow for precise time recovery. The paper also looks briefly on how the Coast Guard’s Loran infrastructure improvements and changes in operational procedures can result in better frequency stability. The paper validates Loran’s ability to meet the timing and frequency requirements by illustrating the results of on-air tests. A test receiver was established at Timing Solutions in Boulder, CO. A near field monitor was installed at NIST in Boulder, CO and a far field monitor at Loran Station Gillette, WY. The three sites were calibrated with respect to each other. An analysis was conducted on the ability to perform precise time and frequency recovery over different distances. Data from the field sites will be presented as well as projections of time and frequency performance based on noise levels experienced in the experimental data.
Published in:	Proceedings of the 2004 National Technical Meeting of The Institute of Navigation January 26 - 28, 2004 The Catamaran Resort Hotel San Diego, CA
Pages:	735 - 739
Cite this article:	Carroll, Kevin, Celano, Tom, Biggs, Casey, Weeks, Gordon K., Jr., "Enhanced Loran for Timing and Frequency," Proceedings of the 2004 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 2004, pp. 735-739.
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