The Many Methods of Communicating with Submarines

https://hackaday.com/2020/07/15/the-many-methods-of-communicating-with-submarines/

by gumby • 6 years ago

120 75 6 years ago

I love reading about stuff like this!

I had 2 questions perpetually on my mind:

1) The article doesn't go into physical sonic wave communication, like ultrasonic I suppose. Did that ever have applications for submarine comms?

2) I always wonder whether like in the movies, submarines actually have or ever use the audible ping. Of course, it gives away one's position instantly, but does such a ping capability even exist still, on modern submarines?

kevinskii• 6 years ago

I was a sonar tech on a nuclear submarine 20 years ago. I don't recall hearing about any ultrasonic applications. As for the "audible ping": Yes, such a capability exists, and it is very much like the movies. It is rarely used for the reason you mentioned.

drtillberg• 6 years ago

Re: #2, that is active sonar, which is for useful for locating objects that are silent, e.g., rocks.[1] It also is very loud and disruptive for whales and dolphins.[2]

[1] https://oceanservice.noaa.gov/facts/sonar.html

[2] https://skeptoid.com/episodes/4236

supernova87a2• 6 years ago

Ah of course, the issue several years ago when the Navy's testing was causing whale / dolphin strandings...

aoki• 6 years ago

1) Yes, it’s nicknamed “Gertrude”.

2) Yes, every tactical platform that hunts subs has an active sonar capability of some kind. (Hull mounted, towed, dipping, sonobuoys, ...) When the ambient noise floor exceeds the target sub’s noise, you need that option.

throw0101a2• 6 years ago

What, nothing about NATO's JANUS?

JANUS performance has so far been evaluated by many collaborating partners at centre frequencies from 900 Hz - 60 kHz and over distances up to 28 kilometers in waters all over the world.
JANUS packet and bit error rates have been computed as functions of the signal to the noise ratio (SNR) and time spread over periods extending from hours to months. Signal correlation times have been computed and long-term experiments by CMRE(external link) in 2008 and 2009 have helped quantify robustness during variable environmental conditions.

* http://www.januswiki.com/tiki-index.php?page=About+Janus

Toolkits available under GPLv3.

* https://spectrum.ieee.org/tech-talk/telecom/wireless/nato-de...

* https://robohub.org/janus-creates-a-new-era-for-digital-unde...

notthetup• 6 years ago

JANUS looks great on paper, but is pretty restrictive for doing anything useful in real life.

At the standard frequency bands they've chosen (9440-13600 Hz), with the type of coding scheme they use FH-BFSK, the bandwidth is too limited (4KHz -> ) to do anything except service discovery.

Having said that, I agree, it should have been mentioned.

throw0101a2• 6 years ago

JANUS looks great on paper, but is pretty restrictive for doing anything useful in real life.

Were they going for reliability rather than bandwidth?

Are there any alternative 'underwater modem/codec' standards?

FabHK2• 6 years ago

“It sometimes seems hard to believe that we humans have managed to explore so little of what we have so much of: the seas.”

Apparently fewer people have been to the bottom of the Mariana trench (between 11 and 12,732 km away from you) than to the moon (about 400,000 km away from you).

RandomBacon• 6 years ago

Visiting the bottom of the Mariana Tench might be feasible for some people here.

Apparently there are three slots available on a first-come-first-serve basis, for $750,000.

https://www.cnn.com/travel/article/marianas-trench-challenge...

Climbing Everest used to be a bucket list item for me, but not anymore after I hear how bad it's gotten over the years.

Going into space seems more feasible for me than the trench, only $250,000.

FabHK2• 6 years ago

Yeah, Mt Everest... nobody goes there anymore, it’s too crowded ;-)

I happened to be in Guam in 2012 and in some dodgy dive bar (...) ran into the crew that took James Cameron down to Challenger Deep, only the second manned descent ever. Didn’t believe them a word until I saw my couch surfing host dancing with Cameron.

codezero2• 6 years ago

I remember researching this in 2008 and I thought satellite based lasers were already in common usage (sending signal to specific known surface location and also receiving from that location using the surface of the ocean as the medium that the sub and satellite read.

This was a while ago so no links maybe I’m misremembering.

dylan604• 6 years ago

they do this with directional encrypted radio. what would be the advantage of doing it with a laser other than 'friggin' laser'?

rocqua4• 6 years ago

Hide the fact of communication instead of the content of communication

codezero2• 6 years ago

What the other comment said. I guess it’s also because of friggin lasers and I may even be misremembering that part. But a laser would have a smaller beam diameter and less likely of interception.

kdeldycke• 6 years ago

Also learned about submarine to satellite direct communications with lasers in a 33c3 video at: https://youtu.be/P4Qk88IpND0?t=32m8s

Source: https://twitter.com/kdeldycke/status/830035138805428224

SaberTail2• 6 years ago

My favorite attempt to get the Department of Defense to pay for physics research is a paper that suggests building a muon storage ring and using that to generate a beam of neutrinos to communicate with submarines[1].

The physical principals are pretty sound. We do already generate neutrino beams, like at Fermilab[2]. And we do have the ability to detect neutrinos in water, optically as ANTARES[3] does, or acoustically, as SAUND[4] demonstrated.

There are some serious engineering challenges to building a muon storage ring, which is why we don't have any. If we could build them, we could build a muon collider. Muon colliders would be great. Muons are elementary particles, and don't have all the garbage inside that a proton does, and so you'd get very clean signals out of such a collider, unlike the LHC. And since muons are much heavier than electrons, it's easier to get them to very high energies without losing a lot of power to synchrotron radiation.

[1] https://arxiv.org/abs/0909.4554 [2] https://www.fnal.gov/pub/science/particle-physics/experiment... [3] https://antares.in2p3.fr/Overview/index.html [4] http://saund.stanford.edu/saund1/

Enginerrrd• 6 years ago

I've often wondered about the feasbility of a private firm doing something similar to dominate the HFT scene by getting a massive lead on information from the opposite end of the globe.

SpaceRaccoon• 6 years ago

They would dominate indeed, but potentially at the detriment of Neutrino research detector sensitivity world-wide.

schoen3• 6 years ago

Avoid the pesky curvature of the Earth's surface by going directly along a chord through the mantle rather than along a great circle?

Using https://planetcalc.com/7725/ and https://planetcalc.com/73/ I just concluded that the straight-line chord distance between Tokyo and San Francisco is 1552 km whereas the great-circle distance is 8270 km. (Neither of these is very precise because it's unclear where in each city you should measure from, and unclear whether either calculator uses data about the irregularity of the Earth's curvature.)

It does make a noticeable difference for HFT applications, I guess: 1552 km/c is about 5 ms while 8270 km/c is about 28 ms. (The neutrinos might do better in another way because I guess light in a fiber doesn't directly follow the curve of the fiber itself, since it's getting repeatedly reflected off of the inside surface of the glass.)

JimTheMan2• 6 years ago

Things that improve HFT sadden me because I don't really see the net benefit to mankind. I see someone else's share of the pie getting smaller, someone's gets bigger and the rest of us remain starving.

jankotek• 6 years ago

Neutrino detection is very slow, it is averaging signal over several hours to transfer a few bytes. Useless for HFT.

hchz6• 6 years ago

I think you might lose for two reasons:

- Conventional RF systems can function with very low latency. The signal processing chain for radiation detection systems is comparatively large, and can require correlation (or anti-correlation) and significant noise reduction or signal separation to construct a useful signal.

- It requires an unbelievable capital investment for low bandwidth. You need a large time advantage to make your PnL on the few names this would support compared to microwaves and other conventional means.

jimbob45• 6 years ago

Wait then why are you implying that they’re pulling a fast one on the DoD when you make it seem like a neutrino beam is a legitimate method of submarine communication?

hchz6• 6 years ago

This sounds like a fantastically complicated way to restore ELF capability, which has already been deprecated.

SaberTail2• 6 years ago

It would work, but physics research would benefit far more than the DoD would, especially since they have other methods to communicate with submarines.

hinkley2• 6 years ago

Also in the plus column you get to call it 'tightbeam communication' and make a bunch of sci fi people very happy.

gopalv• 6 years ago

If we could build them, we could build a muon collider. Muon colliders would be great.

Making muons easy to make/keep will get us closer to a legit cold fusion reactor as a result.

https://en.wikipedia.org/wiki/Muon-catalyzed_fusion#Viabilit...

larrik• 6 years ago

The 228,000 ocean-dwelling species that we know about represents about ten percent of the estimated total aquatic species.

I don't buy it. The idea that the deep ocean is full of all this life we haven't plundered yet seems like a fantasy.

nickff• 6 years ago

They usually make these types of estimates by looking at the rate of new species discovery, and assuming it will asymptotically approach zero.

gerdesj• 6 years ago

Do you have any idea just how vast the seas are? Think about it for a while. Consider that we mostly bob about on top and that is much bigger area compared to dry land. Now allow that it keeps on moving and drops away to up to 11 Km deep. Our senses are nearly useless in this alien world. 10% is just an educated guess and may be woefully low.

waste_monk• 6 years ago

The idea that the deep ocean is full of all this life we haven't plundered yet seems like a fantasy.

It's quite simple, they count the total number of species in the ocean and then use the number of species we know about to work out the percentage.

Sharlin• 6 years ago

"Species" includes arthropods, other invertebrates, and everything else all the way down to single-cellular organisms. And there is an incredible abundance of variety among those forms of life. I doubt we have even catalogued 10% of all species of beetles, never mind of all oceanic life.

akira2501• 6 years ago

The USSR used buoys extensively during the cold war. Here's a former naval officer describing the sonar based system:

https://www.youtube.com/watch?v=Eb6e_-HvBzw

audiometry• 6 years ago

I recently stumbled on this channel. It’s amazing to watch him “twitch stream” analyzing an underwater recording to pull out all sorts of interesting insights while only using a consumer, general purpose audio software.

walrus012• 6 years ago

You can do some pretty effective low bitrate critical satcom stuff with a buoy and molniya orbit satellites. The Russian military has been launching molniya orbit narrowband comms satellites periodically for the past 45 years. They're used for ground, air and naval C4I purposes.

With the long satellite dwell time over high latitude and Arctic regions, a submarine in the arctic ocean could surface a buoy that has a radome in its top, containing a small yagi-uda antenna with a fat oval gain pattern aimed straight up at the sky.

sparker726782• 6 years ago

If you like this kind of stuff checkout "Blind Man's Bluff: The Untold Story Of American Submarine Espionage"

There are so many fascinating details about submarine operations that are now unclassified (and makes you guess about what things are like that are still hidden). From communications to the underground listening stations to attempting (and succeeding) in wire-tapping soviet communication cables, to attempting to lift a wrecked foreign submarine right off the ocean floor.

It's an amazing read and very well written.

dfsegoat• 6 years ago

The audiobook has some nice extra commentary as well.

That book blew the cover off missions that hadn’t been known to the public at all, so it was a bit controversial at release - the commentary touches on all that.

Red November and The Taking of K129 are also great reads along these lines.

sparker726782• 6 years ago

I loved the audiobook, but somehow I missed the controversy part. Thanks for the recommendations!

KineticLensman• 6 years ago

I think you mean 'The hunt for Red October'

b06tmm• 6 years ago

Thanks! I just downloaded the Kindle book.

fortran77• 6 years ago

I worked on the Eaton AIL CVLF radio receiver, which was the one of the first digital radio receivers done in the late 1980s. Because the frequencies used to communicate with subs were around 19 kHz, the CPUs of the time were just fast enough to do the signal processing. We used the Fairchild 9445 which was essentially a Data General "Nova 4" on a chip.

This receiver was used to receive launch commands. It received teletype data that was printed on a Model 29 Teletype. The encryption keys and the key generator used on this project were compromised by the Walkers, a family of spies (See https://news.usni.org/2014/09/02/john-walker-spy-ring-u-s-na... )

The Submarines dragged a wire antenna that was used to receive the VLF radio signals, that were transmitted from several megawatt sites within the US and beyond.

elchief• 6 years ago

I recall an X-Files episode where a woman was affected by the transmission of a ULF or ELF antenna and it was making her crazy. Was a fun episode

Here it is https://en.wikipedia.org/wiki/Drive_(The_X-Files)

gorgoiler• 6 years ago

Ah yes: the other Vince Gilligan TV show starring Bryan Cranston.

hchz6• 6 years ago

You can actually hear some forms of Gertrude through the hull!

I slept with my head right near the hull, and when we did a certain kind of op where it was in use, you could faintly hear what sounded like a home modem.

kayfox• 6 years ago

You can hear it in the movie The Abyss as well, since Cameron is a stickler for accuracy.

hchz6• 6 years ago

I was disappointed with how much this missed:

https://en.wikipedia.org/wiki/Fleet_Satellite_Communications...

https://en.wikipedia.org/wiki/UFO_(satellite)

https://en.wikipedia.org/wiki/Milstar

https://en.wikipedia.org/wiki/Global_Broadcast_Service

https://en.wikipedia.org/wiki/Defense_Satellite_Communicatio...

https://en.wikipedia.org/wiki/Advanced_Extremely_High_Freque...

https://en.wikipedia.org/wiki/Minimum_Essential_Emergency_Co...

The interesting aspects of how USN submarines access these systems doesn't appear to be openly available.

082349872349872• 6 years ago

To some degree one can guess some parameters by reverse engineering the list of dual-use technologies: https://news.ycombinator.com/item?id=23548220

(with my experiences, I see far more submarine detection than communication, but those differently geeky may have better luck.)

matheusmoreira• 6 years ago

FLTSATCOM 7 and FLTSATCOM 8 have been used for repeating UHF Satcom transmissions by unauthorized radio users particularly in Brazil, including criminals, illegal loggers, truckers and individuals located in remote areas.

I wonder how much disruption they're causing...

peter_d_sherman• 6 years ago

"While the high frequency (HF: 3 MHz to 30 MHz) and low frequency (LF: 30 kHz to 300 kHz) bands are perfectly capable of reaching across the globe thanks to ionospheric refraction, the high conductivity of seawater rapidly attenuates signals in these bands.

Dialing down the spectrum a bit, the very low frequency (VLF: 3 kHz to 30 kHz) band starts to exhibit decent penetration of seawater, down to a depth of perhaps 20 meters."

[...]

"Going even further down the spectrum, signals in the extremely low frequency (ELF: 3 Hz to 30 Hz) band are capable of penetrating 120 meters of seawater"

Submarines aside, this is tremendously interesting how specific mediums (in this case, salt water) either act as transducers or attenuators for different radio frequencies.

Now, when a radio frequency is influenced by some form of matter (in this case, salt water, and at higher frequencies, attenuation), it might be because the matter and the radio frequency are somehow related.

In other words, perhaps future scientists will discover that the molecules of water are resonating at a frequency which is a much higher harmonic than the radio waves that they block. And/or perhaps their frequency is somehow related to the much lower frequency radio waves that they conduct.

See, it's sort of like any attenuator can act as a conductor (or vice versa), but the frequency or set of frequencies used makes the determination as to whether the medium in question is going to attenuate or conduct...

Compare this concept to resistors in electronics.

They resist standard DC... but what about AC at a certain frequency, or pulsed DC at a certain frequency?

The higher the frequency (to a certain point when space becomes conductive and thus dissipative with respect to the circuit), the more a resistor should become a conductor...

Also, observation: The reason why distance is lost (in seawater, but also other mediums) when higher frequencies are used, is typically because power is converted into frequency, which then, in the case of a standard radio wave, expands into space as a sphere, that is, it's a inverse-square-law power loss over space.

Compare radio waves to lasers; lasers do not lose power in accord with the inverse-square-law over space...

bertjk• 6 years ago

They resist standard DC... but what about AC at a certain frequency, or pulsed DC at a certain frequency?

Um.. yes. This is actually exactly how you model coupling capacitors when analyzing circuits. You use them to connect two nodes. Apply DC and no current flows through once the capacitor is charged. Apply AC and the signal is transmitted to the other side. The strength of the transmitted signal is dependent on frequency and of course whatever else you have connected to the circuit.

walrus012• 6 years ago

I just did a Ctrl-f on this comments page, and on the article for "iridium", and I'm surprised nobody has mentioned the disposable/expendable iridium buoys yet.

They absolutely exist and come in several varieties. These are not as big a secret as they were 15 years ago. The USN was the first user of such things, but other NATO countries have also purchased and deployed them, or developed their own models.

The Many Methods of Communicating with Submarines

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