New Loran Receiver Technology Significantly Improves Overall System Performance and Substantiates Loran Viability as GPS Backup

G. Linn Roth, Thomas Blandino, and Paul Schick

Abstract:	Although the 199 I addition of South Central and North Central Loran chains greatly improved Loran coverage in North America, Loran receiver technology had not advanced concurrently to take advantage of the increased signal availability and changes in Loran signal conditions. Over the last 5 years, however, new Loran receiver technology has been developed that generates a significant improvement in the overall performance of the Loran system. For example, SNR is typically improved 12 - 18 dB, cycle slips do not occur, and susceptibility to impulse noise and other interferers is almost nonexistent. A single receiver can simultaneously track ground and skywaves from up to 40 Loran transmitters, with some skywaves traveling 5,000 miles reaching levels of 28 dBuV/M. In a practical sense, such performance indicates Loran signals are available for navigation and timing applications over virtually all of North America, from dense urban canyons in Manhattan to remote areas of Northern Canada. Given the recent international expansion of Loran, it also indicates Loran skywave navigation would be available for aviation and marine applications over the northern Pacific and Atlantic oceans to an accuracy of approximately I- l/4 miles. The Loran system has certain characteristics, e.g. low frequency, high signal level, and ground based, that enable it to function under conditions where GPS might be temporarily unavailable. Common examples would be line-of-sight blockage by buildings, man-made interference by communication broadcasts, natural interference from solar flares, and possibly terrorist jamming or spoofing. In addition, the domestic and international Loran infrastructure is already in place, very inexpensive to operate, and Loran has the world’s largest existing user base, Given the significant safety and performance benefits the Loran system now provides at a remarkably low cost, Loran should be the system of choice to backup GPS.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	219 - 234
Cite this article:	Roth, G. Linn, Blandino, Thomas, Schick, Paul, "New Loran Receiver Technology Significantly Improves Overall System Performance and Substantiates Loran Viability as GPS Backup," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 219-234.
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