USCG announces CRADA for alternative to GPS timing

By Brian at January 12, 2012 18:37
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In the Federal Register on January 11, 2012 the Coast Guard announced it was establishing an Cooperative Research and Development Agreement (CRADA) with UrsaNav, Inc. "to research, evaluate, and document... a wireless technical approach for providing precise time using U.S. government facilities and frequency authorizations."

The announcement said they plan to use old LORAN station locations and four frequency ranges:

  • LORAN frequencies (90-110 kHz)
  • dGPS frequencies (283.5-325 kHz)
  • HA-dGPS frequencies (435-490 kHz)
  • former international calling and distress frequency (500 kHz)
It will be interesting to see how this testing goes and to find out more about this technology. There has been a lot of speculation abut what the former LORAN and 500kHz distress frequencies would be used for and a lot of hopes they'd be used to expand communications bandwidth available for e-Navigation uses. Timing information is certainly a valuable component of e-Navigation and a reliable backup to GPS for timing is needed.


End of an e-Navigation era

By Brian at April 26, 2010 08:18
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We know the Coast Guard stopped transmitting Loran-C at most sites on 08 February 2010.  They are moving with alacrity to dismantle this system - a press release was issued on 23 April 2010 stating that the Loran tower at Port Clarence would be taken down in a controlled demolition.  The release doesn't include a date, but a safety zone around the area went into effect on Sunday (I assume that meant Sunday, 25 April 2010; I was unable to find a federal Register notice for the safety zone) so it will likely be very soon.  Apparently the tower is in poor shape, and the demolition is intended to prevent an uncontrolled collapse.

I didn't realize this tower was the tallest structure in Alaska; the release also says the demolition will be "the tallest structure ever intentionally brought down with explosives in a controlled demolition."  I guess if you're going to do something like that for the first time, a remote location in Alaska is a good place for it.  Here's a photo of the site and tower, courtesy of the interesting site

While technological progress is inevitible, and I can't recall the last time I actually saw a Loran box, much less used it, it makes me a bit uneasy to so quickly throw out a proven system, especially since the primary system (GPS) is so different and relatively vulnerable.  As the saying on the charts goes, "the prudent mariner should not rely solely on any single aid to navigation..."  Of course, a good navigator will not rely entirely on electronic aids no matter how many layers of back-ups there are.  I'm pretty sure they're still teacing watch officers traditional coastal navgation techniques and to look out the window every now and then, even if they aren't teaching celestial navigaton any more.

Aviation perspective on Loran shutdown

By Brian at March 19, 2010 07:43
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Interesting perspective from the aviation community on the recent shutdown of Loran.  Kind of alarming to hear that it apparently took some (private) pilots by surprise.