Angissoq Loran-C transmitter
{{Infobox transmitter
| name = Angissoq Loran-C transmitter
| image = LORAN Station Malone-Outside-Large.jpg
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| map_name = Greenland
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| coordinates = {{coord|59|59|18|N|45|10|24|W}}
| built = 1964
| demolished =
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Angissoq Loran-C transmitter was a Loran-C transmitter on the Kitsissut Islands, at the far south of Greenland. It was part of the North Atlantic, Labrador Sea and Icelandic Loran-C chains. {{cite web |title=Loran Station Angissoq |url=https://www.loran-history.info/angissoq/angissoq.htm |website=www.loran-history.info |access-date=9 April 2025 |date=n.d.}}
Loran-C
{{Main|LORAN}}
Loran-C is a system of hyperbolic radio navigation which developed from the earlier LORAN system. It uses low frequency signals from beacons to allow the receiver to determine their position. Conventional navigation involves measuring the distance from two known locations, radio navigation works in a similar way but using radio direction finding.{{Cite book| author=Appleyard, S.F. |author2=Linford, R.S. |author3=Yarwood, P.J.| title=Marine Electronic Navigation |year=1988 | publisher=Routledge & Kegan Paul| pages=77–83 | isbn=0-7102-1271-2|edition=2nd }}
Radio navigation systems use a chain of three or four transmitters which are synchronised. Each chain has a primary station and the others are called secondaries. Each chain has a group repetition interval (GRI) which, multiplied by ten, is the time difference between pulses. The GRI identifies which chain a vessel is receiving.{{citeweb|author=E. Gatterer|url=https://archive.org/details/TheDevelopmentOfLoranCNavigationAndTiming |title=The Development of Loran-C Navigation and Timing|publisher= National Bureau of Standards|date=October 1972}}
Loran-C was replaced by civilian satellite navigation systems starting in the 1990s. The first services to close were in the United States and Canada in 2010.{{Cite web | title = USCG LORAN Program Manager release, Nov. 2009 | date = 31 May 2007 | url = http://www.uscg.mil/ANNOUNCEMENTS/alcoast/675-09_alcoast.txt | access-date = 28 November 2009 | archive-date = 1 December 2009 | archive-url = https://web.archive.org/web/20091201051745/http://www.uscg.mil/announcements/ALCOAST/675-09_alcoast.txt | url-status = live }}{{Cite web|url=https://www.navcen.uscg.gov/?pageName=loranMain|title=LORAN-C General Information|website=www.navcen.uscg.gov|access-date=7 April 2025|archive-date=7 December 2024|archive-url=https://web.archive.org/web/20241207204241/https://www.navcen.uscg.gov/?pageName=loranMain|url-status=live|date=25 November 2009}} In 2014 France and Norway announced they were closing their transmitters, leaving the remaining stations in England and Germany unable to operate.{{cite web|url=https://www.trinityhouse.co.uk/notice-to-mariners/27-15-enhanced-loran-discontinued|title=27-15 Enhanced Loran discontinued|publisher=Trinity House|series=Notice to Mariners|date=1 December 2015}}{{cite web |title=Loran Off Air In Most of Europe - Move to Commercial Possible |url=https://rntfnd.org/2016/01/04/loran-off-air-in-most-of-europe-move-to-commercial-possible/ |website=RNTF |access-date=7 April 2025 |date=4 January 2016 |archive-date=7 February 2025 |archive-url=https://web.archive.org/web/20250207151930/https://rntfnd.org/2016/01/04/loran-off-air-in-most-of-europe-move-to-commercial-possible/ |url-status=live }} The stations in Norway closed on 31 December 2015.{{cite web |title=Etterretninger for sjøfarende |url=https://kartverket.no/efs-documents/editions/2015/efs01-2015.pdf |website=Kartverket |access-date=7 April 2025 |page=26 |language=Norwegian|date=2015}}
Angissoq LORAN-C station
Angissoq station was a member of several Loran-C chains. The North Atlantic chain (GRI 7930) consisted of Angissoq (master), Cape Race (Canada), Edje (Faroe Islands) and Sandur (Iceland). The Icelandic chain (GRI 9980) was Angissoq, Edje and Sandur, and the Labrador Sea chain (GRI 7930) was Angissoq, Cape Race and Fox Harbour (Canada).
The station opened with a {{convert|1350|feet}} mast but this collapsed in August 1964. It was replaced by a {{convert|625|feet}} mast in 1965. It run with a Memorandum of Understanding between the USA and Denmark and most of the staff were Danish.{{cite web |url=https://www.loran-history.info/angissoq/Angissoq-NARA-1967-GIB-wm.pdf |website=Loran History |publisher=US Coast Guard |access-date=9 April 2025 |date=1967|title=General Information Loran Station Angissoq}}{{cite web |last1=Mikkelsen |first1=Aksel |title=Grønlands loranstationer |url=http://www.tidsskriftetgronland.dk/archive/1988-9-Artikel01.pdf |website=tidsskriftetgronland.dk |access-date=9 April 2025 |date=1988|language=Da}}
On 31 December 31, 1994 the transmitter was shut down.{{cite web |last1=Mikkelsen |first1=Aksel |title=Angissoq loranstation |url=http://www.tidsskriftetgronland.dk/archive/1995-2-Artikel04.pdf |website=www.tidsskriftetgronland.dk |access-date=9 April 2025 |date=1995|language=da}} {{cite web |last1=Jensen |first1=Per Møller |title=Pituffik News 5 Station Nord - Greenland Contractors |url=https://www.yumpu.com/da/document/read/51053856/5-station-nord-greenland-contractors |website=yumpu.com |access-date=9 April 2025 |language=da}}