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Old 06-04-2016, 13:50   #1
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Break Out the Sextants

Looks like Pyongyang is playing with GPS signals:

Domestic/News/News/KBS World Radio

Pentagon concerned about North Korea jamming GPS signals, officials say | Fox News

Latest is that they have stopped as of earlier today. I guess the saving grace is that at a basically line-of-site frequency it is hard to put together a wide area jamming signal.
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Old 06-04-2016, 14:27   #2
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Re: Break Out the Sextants

Jamming GPS is incredibly easy, I'm a dummy and I could do it.
Spoofing or sending false signals which would have your plotter still work, but show an incorrect location, isn't easy.
Sounds like they are just Jamming


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Old 06-04-2016, 14:29   #3
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Re: Break Out the Sextants

Either way 33 Korean fishing boats returned to port because they didn't know their position. Of course, that begs the question of how they got back to port
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Old 06-04-2016, 14:35   #4
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Re: Break Out the Sextants

I participated in the "Crab War" of 1999. They take the fishing thing a little too seriously, but there have been severe Famines in the North a few times too, so maybe not.
http://www.atimes.com/atimes/Korea/EF14Dg03.html


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Old 06-04-2016, 17:51   #5
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Re: Break Out the Sextants

The US is reintroducing celestial navigation for naval officers. Not a bad thing.

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Old 06-04-2016, 20:24   #6
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Re: Break Out the Sextants

The news is all from South Korea and the US. I wish someone would ask North Korea if they are jamming GPS.
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Old 06-04-2016, 20:57   #7
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Re: Break Out the Sextants

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Originally Posted by Seymore View Post
The news is all from South Korea and the US. I wish someone would ask North Korea if they are jamming GPS.
You look for the loopiest person in the crowd and point the finger, the majority of the time you get it right.
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Old 06-04-2016, 21:18   #8
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Re: Break Out the Sextants

An old US Navy friend of mine once told me that when relying on GPS and chartplotters for your navigation, "You're a diode away from disaster". I still have and use paper charts when circumnavigation as well as know celestial navigation. What he said made sense to me.
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Old 07-04-2016, 07:31   #9
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Re: Break Out the Sextants

Does that apply to GLONASS also?
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Originally Posted by Dsanduril View Post
Looks like Pyongyang is playing with GPS signals:

Domestic/News/News/KBS World Radio

Pentagon concerned about North Korea jamming GPS signals, officials say | Fox News

Latest is that they have stopped as of earlier today. I guess the saving grace is that at a basically line-of-site frequency it is hard to put together a wide area jamming signal.
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Old 07-04-2016, 07:45   #10
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Re: Break Out the Sextants

For civilian use, GPS is at 1575MHz, while GLONASS is 1598 to 1605MHz. So, a jammer could very easily cover the entire band, but the "news" is silent as to the technical details.

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Old 07-04-2016, 07:49   #11
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Re: Break Out the Sextants

Many think the South China Sea is our most existential threat. All over fish:

Fishing Disputes Could Spark a South China Sea Crisis | Foreign Policy
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Old 07-04-2016, 07:49   #12
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Re: Break Out the Sextants

1985 my 1st Bluewater trip. Long Island NY to Ft. Lauderdale FL. Fresh out of Chapman's. The captain took us almost 200 miles offshore in 17' seas on a Hunter 40. This captain, my 1st experience, was let's say different. Anyway that boat 6 months old leaked and buckled but mostly everything went down. We used just a sextant for 3 days. A ship passing in the early morning, QE2, gave us a fix, with a top of the morning mate. We we're only 1 mile off our EP. Pretty darn good! I remembered what my instructors at Chapman's always said. Trust your work and use electronics to support you. If you rely totally on electronics you'll get screwed eventually. Of course GPS was still a bit in the yachtsmans future, 1984, but coming in quickly. Instructors were all X Navy. Now I just use my ISS apps and dream of being back at sea. Celestial nav is important for the true seaman. Electronics great, but???
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Old 07-04-2016, 08:49   #13
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Re: Break Out the Sextants

I plan to circumnavigate, have my good sextant and and backup, know how to use them, and also have the paper charts. I enjoy the math and the knowledge, I also have a lot of computers, software, many GPS's and hundreds of electronic charts of the world. One needs to have many layers of backup if one expects to succeed. I will mainly use GPS and electronic charts, but know I will probably have to rely on the sextant sometime. I have a steel boat, will carry a welder and also have a machine shop on board. I taught ME and EE, and know electronics will fail and often leave you up a creek. Mechanical equipment will also fail but often you can figure out the problem and jury rig a temporary solution.
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Old 07-04-2016, 10:01   #14
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Re: Break Out the Sextants

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Originally Posted by Dsanduril View Post
Either way 33 Korean fishing boats returned to port because they didn't know their position. Of course, that begs the question of how they got back to port
Maybe they just, could not get on top of the sweet spot for fishing so why waste their time?
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Old 07-04-2016, 10:08   #15
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Re: Break Out the Sextants

I think an issue is that it is a pretty highly contested area, and without GPS or maybe Loran, how do you know your not over the line and fixing to be sunk?
I'd be real surprised if that wasn't the point, sucker some over the line so you could start an incident.
N Korea's leadership was just nuts, now Daddy is gone, Junior is bat crap crazy.
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