{{Short description|Long-range radio navigation system}} {{Lowercase title}} '''Enhanced LORAN''' (commonly known as '''eLoran'''; also known as '''eLORAN''', '''E-LORAN''', or '''e-LORAN''') is a long-range radio navigation system that uses terrestrial towers and the hyperbolic navigation technique. It is an advancement in receiver design and transmission characteristics which increase the accuracy and usefulness of traditional LORAN and LORAN-C.
Interest has been renewed by the potential vulnerability of global navigation satellite systems,<ref name="bbc2010">{{cite web | url = https://news.bbc.co.uk/2/hi/science/nature/8533157.stm | title = Sat-nav systems under growing threat from 'jammers' | first = Jason | last = Palmer | date = 23 February 2010 | work = BBC News }}</ref> and their own propagation and reception limitations.<ref name="bbc2010" /> With reported accuracy as good as ± 8 meters,<ref>{{cite journal |url= http://www.aviationtoday.com/av/commercial/GPS-Backup-Is-eLoran-the-Answer_76148.html |title= GPS Backup: Is eLoran the answer? |journal= Aviation Today |date= April 2012 |access-date= 10 January 2013 |archive-date= 26 June 2012 |archive-url= https://web.archive.org/web/20120626222708/http://www.aviationtoday.com/av/commercial/GPS-Backup-Is-eLoran-the-Answer_76148.html |url-status= dead }}</ref> the system becomes competitive with unenhanced GPS. eLoran also includes additional pulses which can transmit auxiliary data such as Differential GPS (DGPS) corrections, as well as ensure data integrity against spoofing.<ref>{{cite web | url = https://web.stanford.edu/group/scpnt/jse_website/documents/Enhanced_Loran_rv2-short.pdf | title = Enhanced Loran | first1 = Sherman | last1 = Lo | first2= Benjamin | last2= Peterson | date = 3 August 2016 }}</ref><ref>{{cite web | title = Efficient authentication mechanisms for navigation systems – a radio-navigation case study | url = https://www.emsec.ruhr-uni-bochum.de/media/crypto/attachments/files/2010/05/beckeriongnss09.pdf | first1 = Georg T. | last1 = Becker | first2 = Sherman | last2 = Lo | first3 = David | last3 = De Lorenzo | first4 = Di | last4 = Qiu | first5 = Christof | last5 = Paar1 | first6 = Per | last6 = Enge | access-date = 11 March 2019 | archive-date = 29 November 2019 | archive-url = https://web.archive.org/web/20191129034117/https://www.emsec.ruhr-uni-bochum.de/media/crypto/attachments/files/2010/05/beckeriongnss09.pdf | url-status = dead }}</ref>
eLoran receivers use "all in view" reception, incorporating signals from all stations in range, not solely those from a single Group Repetition Interval (GRI), incorporating time signals and other data from up to forty stations. These enhancements in LORAN make it adequate as a substitute for scenarios where GPS is unavailable or degraded.<ref>{{cite web | url=http://www.loran.org/news/LORAN%20FINAL%20DHS%20Press%20Release.pdf | title= Statement from DHS press secretary Laura Keehhner on the adoption of national backup system to GPS | author= Press office| date= 7 February 2008 |work= press release | publisher= United States Department of Homeland Security | access-date= 10 January 2013 | archive-url= https://web.archive.org/web/20080514011837/http://www.loran.org/news/LORAN%20FINAL%20DHS%20Press%20Release.pdf | archive-date=14 May 2008 | url-status=dead }}</ref>
In 2017 it was reported by the United States Maritime Association that the United States Coast Guard had reported several episodes of GPS interference in the Black Sea.<ref>{{cite web|url=https://www.maritime.dot.gov/content/2017-005a-black-sea-gps-interference|archive-url=https://web.archive.org/web/20190701092824/https://www.maritime.dot.gov/content/2017-005a-black-sea-gps-interference|url-status=dead|archive-date=July 1, 2019|title=2017-005A-Black Sea-GPS Interference|author=U.S. Maritime Association}}</ref><ref>{{cite web|url=https://www.maritime.dot.gov/content/2017-007-global-gps-disruption|archive-url=https://web.archive.org/web/20200928171649/https://www.maritime.dot.gov/content/2017-007-global-gps-disruption|url-status=dead|archive-date=September 28, 2020|title=2017-007-Global-GPS Disruption|author=U.S. Maritime Association}}</ref> South Korea has claimed that North Korea has jammed GPS near the border, interfering with airplanes and ships. By 2018, the United States planned to build a new eLoran system as a complement to and backup for the GPS system. The South Korean government has pushed plans to have three eLoran beacons active by 2019, which would be enough to provide accurate corrections for all shipments in the region if North Korea (or anyone else) tries to block GPS again.<ref>{{Cite web|url=https://arstechnica.com/gadgets/2017/08/radio-navigation-set-to-make-global-return-as-gps-backup-because-cyber/|title=Radio navigation set to make global return as GPS backup, because cyber|first=Sean|last=Gallagher|date=7 August 2017|website=Ars Technica}}</ref><ref>{{Cite web|url=https://www.gps.gov/policy/legislation/loran-c/|title=GPS.gov: LORAN-C Infrastructure & E-LORAN|website=www.gps.gov}}</ref><ref>{{cite web |last1=Narins |first1=Mitch |title=The Global Loran / eLoran Infrastructure Evolution: A Robust and Resilient PNT Backup for GNSS |url=https://www.gps.gov/governance/advisory/meetings/2014-06/narins.pdf |website=GPS.gov |publisher=Federal Aviation Administration |access-date=2022-11-13 |date=2014-06-03}}</ref> As of November 2021, no eLoran system has deployed.<ref>{{Cite web|url=https://www.gpsworld.com/eloran-part-of-the-solution-to-gnss-vulnerability/|title=ELoran: Part of the solution to GNSS vulnerability|date=3 November 2021}}</ref>
==See also== * CHAYKA * Loran-C
==References== {{Reflist}}
Category:Navigational aids Category:Aeronautical navigation systems