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Wonderful article published in GCaptain today.
Apparently merchant vessels have no backup navigation system if GPS fails (what planet do some of these guys come from).
Therefore consideration is to be given to developing e-loran as a backup.
Apparently some vessels had their GPS signals hacked and had to return to port!!!!
 

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Best quote is "if the GPS fails, ships run the risk of colliding or running aground".
Wow, sounds dangerous to be at sea nowadays.
 

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But Julian haven't you been following the blogging here on reliance on GPS. There is a body of experienced navigators who are happy to rely on just GPS (of course not for ship dodging)? We have been fed the need for spending on hybrid Glonass/GPS receivers and the development of Galileo as back ups. I would favour something that did do entirely without the space segment preferably a ham bone, charts and sensible passage plans that did not seek to squeeze passed geology unsuitable for the passing of by squeeze. Failing that eLoran would do.
 

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I think the USA dropped the requirement for a while and then had second thoughts. I am sure we could all manage the theory for an exam but is a sight taken once a week or month for compliance with operational procedures enough to keep up the skill and accuracy that comes with that?
 

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Decca Main Chain was developed for the Normandy landings. Ships travelled down an allocated lane and then switched to the second allocated lane giving them a dog leg into the beachhead. It was not a position fixing system, merely a guide and without it, Normandy would not have been possible considering the number and complexity of craft involved. It was switched off immediately after the landings in case the Germans realised what it was and how it worked.

It was developed from an idea from an American engineer whose career was on hold after contracting TB and the initial trials took place in California but neither the US Airforce or Navy were interested. The UK eventually saw its potential and developed it off Angelsey.
 

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Perhaps it's worth mentioning also that some decapitating event such as an exceptionally huge solar flare could not only knock out GPS but all the Comms as well, world wide. We might be able to repair or counter a hack, but the Sun is a whole different ballgame. Not that a rusting old Morse key would be of any help because it needs both ends.

We all saw recently how a minor software failure bought BA to its knees.

I sort of have a hankering to be in a 'post apocalyptic' world, and each day I see the news, I think it's getting closer. [=P]
 

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Decca Main Chain was developed for the Normandy landings. Ships travelled down an allocated lane and then switched to the second allocated lane giving them a dog leg into the beachhead. It was not a position fixing system, merely a guide and without it, Normandy would not have been possible considering the number and complexity of craft involved. It was switched off immediately after the landings in case the Germans realised what it was and how it worked.

It was developed from an idea from an American engineer whose career was on hold after contracting TB and the initial trials took place in California but neither the US Airforce or Navy were interested. The UK eventually saw its potential and developed it off Angelsey.
I always understood that Decca was developed for bomber command to improve their bombing accuracy.
 

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I always understood that Decca was developed for bomber command to improve their bombing accuracy.
John, the RAF was approached but opted to stick with the problematic Gee system, it was the Navy that spotted the potential especially in that Gee and Gee H were limited in user numbers, Decca was unlimited.
 

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Looks like GEE was the first hyperbolic navigational aid and that that was used by the RAF bomber command.

The latest form of navigation aid being investigated by the Chinese is X-ray pulsar XNAV using X ray emission from space.

Another interesting one being investigated at the NPL is quantum inertial systems http://www.npl.co.uk/news/quantum-timing-navigation-and-sensing-showcase-at-npl
The X ray pulsar is an interesting idea since you have a large constellation of free natural sources which even the most ardent hacker is going to have trouble messing with. (EEK)
 

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John, the RAF was approached but opted to stick with the problematic Gee system, it was the Navy that spotted the potential especially in that Gee and Gee H were limited in user numbers, Decca was unlimited.

I stand corrected , thanks for the explanation.
 

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janmike
Ever tried finding your longitude by watching the sun set. It was an idea for use in lifeboats. Interesting it does work to a degree or so
 

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I think the USA dropped the requirement for a while and then had second thoughts. I am sure we could all manage the theory for an exam but is a sight taken once a week or month for compliance with operational procedures enough to keep up the skill and accuracy that comes with that?
The US has never dropped the celnav requirement for the ocean Merchant Marine licenses. I think that you are referring to the US Naval Academy dropping the requirement for all midshipmen. The QM's still have to know it.

In fact, the CM/Masters exams has some odd-ball reductions like ex-meridian of lower transits and circles of equal altitude. For assessments they have to shoot a non-solar transit and an ex-meridian. So celnav is alive and well, but how much anyone really remembers is up for debate. I am currently mentoring my 2nd mate on the fine art as she is slated to take her CM/Master test after this tour.

I harp on celnav on my ship, but I'm one of the few masters who seems to understand that if the GNSS fails, we are back to DR's and Celnav until we can get within radar range of land since there isn't anything else out here.
 

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Jeremy. I said I am sure we could manage the theory not that we HAD managed the theory.

Good to hear you are following the true path. Many here would see it consigned to the bin. Would they go for a drive without the wherewithal to overcome a punctured tyre? (Yes, probably!)
 
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