Cyber threats prompt return of radio for ship navigation.

Ah, I see. I thought you meant something like on-off keying for radio navigation beacons. Even so I did the math once on energy use based on words per watt-hour for different modes of communications, comparing things like manual CW, automated CW, a couple radio teletype modes, and SSB voice, and as I recall on-off keying didn't look good. I think I gave a budget of something like 70 watts for a computer which would be far more than what would be needed today. Maybe I'll repeat that thought experiment again. I suspect the best plan "B" for a failure of your SSB gear is a spare set of SSB gear.

 

All said and done, it's kinda like tossing out all your maps and asking the city to remove all the road signs because you now have a GPS. When we used to travel a lot on motorcycles, we did use a GPS, but at least one of us always had a copy of The Roads Of Texas, because it usually had *every* road on it, including the pig trails. More than once, the GPS was just wrong, but the map was right.

 

This is actually the reasoning behind the "duplication of equipment" maintenance option in the GMDSS that most ship-owners use today.

Carrying spare-parts and having qualified on-board repair personnel is far more expensive for first-world merchant navies.

Regarding power outages enroute, the loss of maneuverability is far more dangerous than any loss of ECDIS or AIS presentation.
Besides, current classification society rules call for an UPS capacity for essential bridge functions of at least 60 minutes. Most settle for the 6 hours of battery and emergency generator operation which is required of a GMDSS radio installation.

e-Loran is frequently discussed as a "sanity check" and back-up function for PNT application. However, it does not give the accuracy required for precision navigation in congested waters. If GPS should become unreliable, any AIS based navigation can only continue with reductions in speed and larger separations between vessels.

Loss of GPS enroute on high-seas is a quite moot point. The sea is large enough to accomodate navigation by dead-reckoning for quite extended periods. Besides, any large-scale jamming of GPS on the high-seas would be a major undertaking by a world power.

This could only be of interest in case of a large scale conflict, and in that case we have far more pressing worries...

73/
Karl-Arne
SM0AOM

 

Cheap shot!

 

For those with an interest in history, below is the link for the memoirs of J.A. Pierce (W1JFO; SK now for many years) who invented (along with others) LORAN, and OMEGA. FYI, my interest is defined by the fact that I worked for Jack when I was a teenager, in his lab.

The memoirs are not edited, were written over almost 20 years, and have gaps and several sad and abbreviated chapters. However, much of the LORAN and OMEGA sections are detailed, vibrant and fascinating:

http://phk.freebsd.dk/misc/jack_pierce.html#Barharbor

73
Chip W1YW

 

Chip,

Wow! Thanks for posting this link. While the story of the science and technology is fascinating, the humanity and humor in the tales of Jack's life are riveting. Timely too, pertinent to the OP but ironically also including an eclipse expedition. It will occupy my casual reading for quite some time.

73 de John - WØPV

 

This made me curious if there are any modernized electronic or digital sextants. While there are some stand-alone devices on the market, I noticed there are also apps for Smartfones.

Like Spyglass for iOS, and others for Android. Using the former seems quite simple elegant by holding the phone up with the front camera viewing the live sky and overlapping and matching navigation stars to a stored star field chart image.

Has any one here actually used these apps and have comment on their accuracy or usefulness?

73 de John - WØPV

 

Look at it from the point of view of the responsible airline, shipping companies, and the crews they hire. They will look are the GPS receivers, compasses, radios, this, that, and the other thing, all in duplicate or triplicate. Then the government comes along and says, "We think that's not enough, you need this on board too. Oh, and a spare."

I don't remember the details on the fight to get the FAA and such to allow two engine aircraft to perform transoceanic flights. I do recall reading about a case, and I'm likely getting the details wrong, of a pilot flying over the ocean when one of the two engines failed. As I recall it was something like being just short of the halfway point on a 3.5 hour flight with an aircraft rated for 2 hours of flight on a single engine. Rather than turn back the pilot continued to his destination. He didn't keep the engine failure as a secret, he reported the problem, his intention to continue, and (again, as I recall) no one questioned him until he landed. I don't recall him getting fired or sued over this but it made the news enough that I, who is not a pilot, heard of it.

Was this safe? Of course not. Flying on one engine, over water, and not have flotation landing skis, is not safe. It does sound to me though that he made a logical choice and the risks of one over the other was so small that it's real hard to claim any passenger's life was at any more risk either way. Did he break protocol? Perhaps. What seems clear to me is that things break, and that's not going to change, life is dangerous, that's not changing either, and no matter what we do to make things "safer" there will always be another thing to make use "safer" yet. There's a point somewhere of reaching the absurd.

What we have here is a bunch of people in government looking at a potential failure of GPS and what to do about it. First, this is unlikely to happen over any extended period of time or over extended areas. Second, the crews are already trained on how to handle navigation equipment failures. Loran just duplicates one single point of failure system with another system with a single point of failure. If the problem is jamming and spoofing then can't a determined attacker hit both at the same time?

As I recall one argument against Loran was that each site was a big juicy target for adversaries to take out and cripple shipping. I say if we are going to make these ships and planes carry another piece of equipment then make it as self contained as possible. Inertial and celestial navigation is exceedingly accurate now. Judging by some of the stuff I've seen people do with off the shelf stuff these could be also very cheap. No one is going to block out the sun, and if there is a power failure on board then GPS is gone, Loran is gone, and the crew is down to compass, watch, charts, the sun, and the moon.

Also, I recall talking to someone that was on a Navy ship and showed me some pictures he had of the deck. He pointed to this antenna array on the front that looked like a big tuning fork. Most of the time it's folded down so as to not interfere with the operation of the deck guns. If there's a navigation failure though this antenna can be deployed and someone with pretty basic ideas of radio navigation and some charts of known radio beacons, broadcast radio stations, or anything with a known position and frequency, all of which becomes a navigation beacon, can get them where they need to be. This can be automated. Instead of a Loran network, and special Loran receivers, give them a system that can use any given radio station as a navigation beacon. A computer with a wide band RF receiver, a pair of antennas, and a large enough database of existing stations, can figure this out.

With inertial navigation, celestial navigation, and radio navigation from existing transmitters, all very accurate, inexpensive to automate, and requires no new infrastructure, I'd think someone can come up with something better than Loran. Especially since Loran has much of the same vulnerabilities that they claim they're trying to address from GNSS.

I'm sure I'm missing something here, like how much money some Senators can divert from federal coffers to their state if Loran is taken out of mothballs.

 

Good comments Karl-Arne. Since nav on open seas is inherently less dangerous and can easily use other methods to prevent getting lost, it would seem that the real threat is mostly collisions, arising not so much from loss or jamming of GPS (GNSS) but rather to ignorance, inaccuracy and/or insecurity of the current standard AIS.

Which as presently implemented appears to quite vulnerable to more sophisticated hacking, ie, spoofing, hijacking, DoS, etc So development of more precise and robust non-sat based AIS would probably be a better investment then eLORAN.

 

I would also assume there might be a reason for the friendlies to jam or turn off GPS if they emeny was using some sort of GPS-guided weapon, drone, etc... eLoran might be a bit hard to implement in a small rocket versus GPS, so they could disable or jam GPS to make these things miss their targets.

 

AIS in its present form is not per se dependent on GPS, due to its self-organising properties, but loss of GPS positioning and timing would degrade the performance.

It is ages since I saw LORAN-C "in the flesh", but the dynamic accuracy for slow-moving users was in the 10-s of meters.

This may not be sufficient for safe AIS-based navigation in congested waters such as estuaries and harbours.

73/
Karl-Arne
SM0AOM

 

What I don't understand is why a solely radar based AIS system (no external reference, ie, GPS / LORAN) apparently is so imprecise or not responsive enough to measure RELATIVE position between ships to be useful enough to prevent them from colliding. If it is working now for automobiles / aircraft, why not at sea?

Running into a lighthouse or bridge , or hazard of nature, of course is another matter; unless it's also equipped with an active AIS xponder.

 

What you are talking about is essentially the anti-collision radar function.

It works, but has one drawback in close vicinity situations, as its algorithms have difficulties to decide how fast and in what direction a ship is making a turn.

For these reasons, "sensor fusion" is commonly used in modern ECDIS equipment, where data from several sources are weighted together before being presented on the displays.

A bridge or lighthouse collision is much easier to prevent, as they are not moving by themselves. They may also have a radar reflector or RACON to enhance their visibility. Also, a RACON based AIS system (ITOFAR) was actually proposed in the mid-80's by at least one radar manufacturer.

It would have worked something similar to the SSR or ADS-B system used in aviation, where a transponder is interrogated by survelliance or navigational radar.

73/
Karl-Arne
SM0AOM

 

Typical lack of knowledge from the writers of the article, in particular this quote from the article>>>adopting versions of the technology, which works on radio signals.

Hello writers and editors, are you aware that GPS also relies on radio signals just like Loran and ELoran does or did they think that GPS works with magic fairy dust?

 

I think it is more about being able to track RF jammers.

This could be good for ham radio.