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.


And another one gone...

By Brian at September 18, 2010 15:30
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No tower demolition this time (yet) but another LORAN station is decommissioned.

Here's the Loran History website for this staton; that's where I got this photo:

Another one bites the dust

By Brian at August 28, 2010 09:26
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From USCG press release:

Attu, Alaska – The Coast Guard demolished the 625-foot Long Range Aids to Navigation tower in Attu home of the westernmost Coast Guard unit in Alaska Wednesday before LORAN Station Attu is scheduled to be decommissioned August 26. Due to the deteriorating condition and with no funding for repairs, the station’s 625-foot LORAN tower was becoming an ever-increasing risk of uncontrolled collapse. The Coast Guard began decommissioning its LORAN infrastructure in response to direction from Congress provided in the 2010 budget. LORAN Station Attu ceased transmission of the LORAN signal Feb. 8, 2010 and the Russian-American signal ceased Aug. 1, 2010.

See the video here.

Old and older...

By Brian at June 28, 2010 14:17
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That's Cape Hatteras Light (older) on the right and a Loran tower* (old) in the center distance (it may be hard to make out).  Another photo I took includes even older - the foundation of the original location of the Cape Hatteras light where it was erected in 1872 (it was moved in 1999 to its current location) which is near where the original light was built in the early 1800s.


Something curious to consider as we move forward with e-Navigation - the "newer" technology (Loran) is not in use anymore but the light is still going strong 138 years after it was established, probably another 100 years or so after a light was first placed there and thousands of years after the first use of lighthouses.  Navigation by visual means is still a critical part of seafaring, and will continue to be so no matter what technological wonders e-Navigation brings.


In order to be successful, e-Navigation must accommodate existing forms of navigation, in particular visual navigation.  There has been a lot of talk about how lights, buoys, beacons and other visual aids can be reduced or even eliminated as we head into the brave new e-Nav future.  Besides the obvious need for redundancy and backup ("what will you do when the generator dies/batteries go flat/system crashes/GPS is jammed," etc.), these are time-tested, reliable, refined tools for the navigator, not to mention they exist in the same real world as the vessel and the navigator.


e-Navigation must thoughtfully, gracefully and elegantly incorporate and enhance traditional navigation methods in order to be accepted, successful and ultimately useful.



     *I'm pretty sure that's the Loran tower; in any event it's in the right location.  According to, Cape Hatteras had a Loran-A station until 1980.

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.