{"id":8634,"date":"2010-02-12T17:29:52","date_gmt":"2010-02-12T22:29:52","guid":{"rendered":"http:\/\/www.shotinthedark.info\/wp\/?p=8634"},"modified":"2010-02-12T17:29:52","modified_gmt":"2010-02-12T22:29:52","slug":"loran-time-no-see","status":"publish","type":"post","link":"http:\/\/www.shotinthedark.info\/wp\/?p=8634","title":{"rendered":"LORAN Time No See"},"content":{"rendered":"

I’ve joked, over the years, about how my native North Dakota is a maritime state, peopled by folks with salt water in their veins.\u00a0 It’s partly a joke, of course – NoDak is pretty land-locked.\u00a0 Not entirely a joke, of course; many of us are descended from the Vikings (not the ones that choke in the playoffs – the ones that made all your anscestors cry “uncle”).<\/p>\n

But at least partly because North Dakota had a Coast Guard base.<\/p>\n

For the past forty-odd years, thirteen of the loneliest coasties in the entire service have manned a LORAN transmitter near the little town of Lamoure.\u00a0 The station broadcast a continuous signal with about four megawatts of power (most of our metro TV stations and bigger FM stations are 100,000 watts) to ships and planes around the world; in the days before GPS, it was the gold standard of electronic navigation.<\/p>\n

Was.\u00a0 The system was officially shut down this past Monday<\/a>:<\/p>\n

On Monday at 2000 GMT, the U.S. Coast Guard terminated the transmission of the LORAN-C radionavigation signal, marking the end of a system which has been an important factor in maritime navigation (and, to a lesser extent, air navigation) for more than half a century. The termination of LORAN was based on budget considerations and on the conclusion that LORAN\u2019s functions have been supplanted by GPS. I\u2019m not totally sure that this was a good decision.<\/p><\/blockquote>\n

LORAN was developed in World War II, and has served well.\u00a0 But time and technology march on.\u00a0 But progress doesn’t always progress, really:<\/p>\n

Most LORAN users have now converted to GPS: however, there are signficant concerns about the increasing level of navigational dependency on this satellite-based system. For one thing, GPS signals are necessarily weak and can be jammed relatively easily. This was much less of a threat for LORAN because of the very high power (up to 4 megawatts) of its terrestrial transmitters.<\/p><\/blockquote>\n

So powerful, in fact, that they’d kill birds in flight near the towers.<\/p>\n

Various proposals have been advanced for GPS backup systems, one of which involves radio signals transmitted from blimps. An alternative that was on the table was e-LORAN, involving the upgrade of the system\u2019s accuracy to about 8 meters: indeed, significant money has already been invested in e-LORAN development. I\u2019ve seen estimates that the cost of completing e-LORAN deployment would have been about $250MM, which is roughly the same amount of money being spent to dismantle the existing LORAN infrastructure. (LORAN operating costs were quite reasonable, about $35MM\/yr.) I wouldn\u2019t be surprised if whatever we wind up doing for GPS backup turns out to cost a lot more.<\/p><\/blockquote>\n

Of course, GPS developers have a lot more political clout than LORAN technicians, these days.<\/p>\n

Anyway – bon voyage, LORAN!<\/p>\n","protected":false},"excerpt":{"rendered":"

I’ve joked, over the years, about how my native North Dakota is a maritime state, peopled by folks with salt water in their veins.\u00a0 It’s partly a joke, of course – NoDak is pretty land-locked.\u00a0 Not entirely a joke, of course; many of us are descended from the Vikings (not the ones that choke in […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-8634","post","type-post","status-publish","format-standard","hentry","category-geekery"],"_links":{"self":[{"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/posts\/8634","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8634"}],"version-history":[{"count":3,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/posts\/8634\/revisions"}],"predecessor-version":[{"id":8639,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=\/wp\/v2\/posts\/8634\/revisions\/8639"}],"wp:attachment":[{"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8634"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8634"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.shotinthedark.info\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8634"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}