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Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

thedrive.com

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Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#71

Post by vmh1928 »

justanotheranon wrote: post #26
adriancooney wrote: post #4

I'm not normally one to promote Hollywood but the film Greyhound (2020) with Tom Hanks does an _excellent_ portrayal of this technology (albeit slightly more primitive) in fighting German U-Boats in WW2. Well worth a watch if this interests you.

the British cracked Enigma in 1941, and from then they were able to completely destroy the 300-400 German u-boats, because they were intercepting and decrypting u-boat radio traffic, so they always knew where the u-boats were going. The only reason the Allies allowed the u-boats to continue winning small victories was to preserve the illusion that Enigma was still secure to prevent the Germans from switching to anoth…

The book "Marching Orders" by Bruce Lee tells the story of Magic intercepts of the Japanese military and diplomatic code and reviews the daily summaries read by Marshall and other US leaders in the context of what was happening in the war at that time The point of the book, c.1995, was that signals intelligence played a huge role, but unknown role, in influencing the actions of the U.S. and U.K. And that without understanding what the leaders knew there is a tendency to overestimate their skill / leadership ability.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#72

Post by hchz »

zkms wrote: post #59
mhh__ wrote: post #18

Earlier quoted context omitted.

That's if they aren't already. Without having the data I can't try but I'd guess that Fourier analysis (or something a bit more clever to deal with noise e.g. Welch) would get you a lot of the way there even without invoking AI

This is not based on any classified information and sonar signal processing is not something i know much about, but cyclostationarity (and other higher-order statistical signal processing) does tend to be useful when processing signals that are generated by processes where there's multiple periodicities at work: https://en.wikipedia.org/wiki/Cyclostationary_process#Angle-...

Signal separation techniques for characterizing cyclostationary signals are also more robust to noise. For example, analysis of the second order FFT can resolve the signals of incipient faults in rolling bearings because it can resolve the signals of the bearing components rotating (at a much lower frequency than the shaft) whereas simple FFT analysis would generally only measure the magnitude of the structural resonance of the machine, with spikes at the mains, rotational, and slip frequency.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#73

Post by hchz »

I used to be a part of this when the tracking party was manned and I was engine room sup.

Using the computer tools For fusion was definitely interesting (90’s X11 gore), with a large palette of modeling tools, but the coolest experience was being taught to time/range plot on paper by the mustang weps.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#74

Post by GCPGCP »

epiphanitus wrote: post #67
adriancooney wrote: post #4

I'm not normally one to promote Hollywood but the film Greyhound (2020) with Tom Hanks does an _excellent_ portrayal of this technology (albeit slightly more primitive) in fighting German U-Boats in WW2. Well worth a watch if this interests you.

There's actually a former US Navy Sonarman who has a youtube channel called Sub Brief and it's amazing. He left the service in 90s (IIRC) but he shares all kinds of interesting knowledge on how torpedos and mines work, all the different kinds of accidents and mishaps that happen - he even analyzes different disasters like the Kursk and how they likely happened. I highly recommend it if you're into subs. https://www.y…

JiveTurkey and Aaron Amick (author of this article) are the same person :)

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#75

Post by GCPGCP »

Anechoic wrote: post #34
MrBuddyCasino wrote: post #19

Earlier quoted context omitted.

235db! Apparently also kills wales and dolphins. https://physics.stackexchange.com/questions/93222/could-subm...

Keep in mind that's likely not related to the dB sound pressure level in air that we're all familiar with. dB is a logarithmic ratio to pressure to a reference. In air, that reference is 20µPa, acoustic pressure in water typically uses a different reference (1µPa). There is also an adjustment of 36 dB to account for the higher impedance of water. So 235 dB in water is roughly 173 dB SPL -- still loud, but many orders…

This is what you can expect https://www.youtube.com/watch?v=sCmyZYYR7_s&t=90s

This diver was near a sub base for training.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#76

Post by remarkEon »

GCPGCP wrote: post #74
epiphanitus wrote: post #67

Earlier quoted context omitted.

There's actually a former US Navy Sonarman who has a youtube channel called Sub Brief and it's amazing. He left the service in 90s (IIRC) but he shares all kinds of interesting knowledge on how torpedos and mines work, all the different kinds of accidents and mishaps that happen - he even analyzes different disasters like the Kursk and how they likely happened. I highly recommend it if you're into subs. https://www.y…

JiveTurkey and Aaron Amick (author of this article) are the same person :)

I recently got into realistic combat simulators (Squad, Arma, DCS, Cold Waters ... there are some other sub sims out there too) and I had no idea JiveTurkey and Aaron were the same person. Maybe I just missed it or wasn't paying attention.

Anyway, if you're a military geek and want to get into realistic naval combat sims play Cold Waters (Uboat is also good, but way different play style). Like all realistic sims the learning curve is pretty steep, but during lockdown having something to concentrate on and enable a bit of a disconnection from the rest of the world for a while is nice.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#77

Post by Ao7bei3s »

tantaman wrote: post #68

Oh man, I worked on the software for these systems for 6 years :) specifically the ones from this image https://www.thedrive.com/content-b/message-editor%2F15972209... During the holidays we'd pump Christmas music through the sensors. We could do this since that's what the raw data is anyway -- sound. Made for interesting sonar displays as well as background music.

If you can say, what does the dev version look like, physically? I assume you don't have a dev ship? So same HW, just in an office? Or remote access to HW in a server room? Or is there a more desktop friendly form factor? Or all virtualized?

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#78

Post by pgreenwood »

justanotheranon wrote: post #26
adriancooney wrote: post #4

I'm not normally one to promote Hollywood but the film Greyhound (2020) with Tom Hanks does an _excellent_ portrayal of this technology (albeit slightly more primitive) in fighting German U-Boats in WW2. Well worth a watch if this interests you.

the British cracked Enigma in 1941, and from then they were able to completely destroy the 300-400 German u-boats, because they were intercepting and decrypting u-boat radio traffic, so they always knew where the u-boats were going. The only reason the Allies allowed the u-boats to continue winning small victories was to preserve the illusion that Enigma was still secure to prevent the Germans from switching to anoth…

And Poland cracked Enigma in 1933, and then shared their techniques and Enigma clones with the British in 1939!

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#79

Post by james_s_tayler »

Ao7bei3s wrote: post #77
tantaman wrote: post #68

Oh man, I worked on the software for these systems for 6 years :) specifically the ones from this image https://www.thedrive.com/content-b/message-editor%2F15972209... During the holidays we'd pump Christmas music through the sensors. We could do this since that's what the raw data is anyway -- sound. Made for interesting sonar displays as well as background music.

If you can say, what does the dev version look like, physically? I assume you don't have a dev ship? So same HW, just in an office? Or remote access to HW in a server room? Or is there a more desktop friendly form factor? Or all virtualized?

It would be fun to be that guy saying but dev/QA/prod should all look the same.

Re: Veteran submariner on how sonar crews tirelessly hunt enemies they can't see

#80

Post by GCPGCP »

remarkEon wrote: post #76
GCPGCP wrote: post #74

Earlier quoted context omitted.

JiveTurkey and Aaron Amick (author of this article) are the same person :)

I recently got into realistic combat simulators (Squad, Arma, DCS, Cold Waters ... there are some other sub sims out there too) and I had no idea JiveTurkey and Aaron were the same person. Maybe I just missed it or wasn't paying attention. Anyway, if you're a military geek and want to get into realistic naval combat sims play Cold Waters (Uboat is also good, but way different play style). Like all realistic sims the…

688(I) Hunter/Killer with the Jane's manual is great too. I find it more immersive than Cold Waters as you are in charge of the waterfall and have to move the cursor like a true sonarman to find the good signature.
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