Diver Detection Sonar

[quimby]

In Cape Canaveral...we are trying to develope passive acoustics....an ear that listens...no active sonar

Joe

30+years ago they called it the " SOSUS (SOund SUrveillance System)". Just ask the navy and CIA how they found (heard) the Russian sub that broke up in the Pacific and we tried to pick it with the "glomar explorer" from 17000ft

3DENT

If you heard it, it you weren't being tracked. Sonar in the audio range doesn’t have the resolution to pick up small targets

Your right as the discrimination ability of a unit is dependant on freq and pulse length.
What you hear or feel isnt the "Tone" or xmitted frequency, its the pulse rep rate, and if your up close you'll feel the snap like a arc from a spark plug or similar. Im talking small systems like commercial grade side scans or forward searching or even depth finders with some punch.
All bets are off if we get into phased array and cont FM and fancy stuff but the above stands for the usual pulsed sonar units

 

[Rickg]

Hence your location, San Diego. Sometimes people think that the Gov't watching is a bad thing, I'm glad you don't and I know I have nothing to hide.

dlndavid,

Actually never lived in CA until after I retired but you won't find me complaining much about San Diego, especially since we moved here in early '98 and bought a home when the real estate market was rock bottom. Now only if the water was warmer.

Rickg

 

[Rickg]

In Cape Canaveral...we are trying to develope passive acoustics....an ear that listens...no active sonar

Joe

cudachaser,

The Navy has been doing passive acoustics for years. Unfortunately, the shallow water/littoral areas are a very difficult problem to solve. You should look into the Navy's Mobile Inshore Undersea Warfare (MIUW) program.

Rickg

 

[Jai Bar]

If you heard it, it you weren't being tracked. Sonar in the audio range doesn’t have the resolution to pick up small targets.

Your link isn’t working. Were you diving someplace where the Navy or CG might think you were a threat?
E]

And why is that? Which frequencies do you think have the resolution to pick up "small targets"? BTW, assuming a speed of sound of ~1500 meters/sec, and suppose we can hear frequencies between 20-20000 Hz, then you receive wavelengths of 75m down to 7.5cm - so at least the higher range of frequencies in the audible spectrum have the ability to resolve relatively small targets. Moreover, frequency alone is not the only parameter of importance- sonar pulse duration and acoustic beam shape affect the ability to detect tagets, as well as the properties of the target reflecting the sound waves, the array of hydrophones receiving the reflected signals etc. etc.

 

[m3830431]

Just in case you want to swim acrouse the Atlantic with a shoe bomb.

 

[MaresMan1]

RickG, is correct.

The DoD and Dept of the Navy have been working on surveillance systems for years. The key word is systems, comprised of Sonar, Hydorphones, Lightwave systems, etc. Everything in the water has a distinct signature. Collect samples of different creatures, cross referrenced and how they move in water and create a database. The unit used to be called ULSS (Undersea Lightwave Surveillance Systems). Lightwave referred to the linking communications medium. Covers all of our domestic coasts, including Hawaii and Guam.

Big Brother has been watching and recording for years and getting better at it.

Dive Smart; Dive Safe
Enjoy the ride
:14:

 

[Don Burke]

We figure it was active sonar that we were hearing three years ago on this dive. I'm sure that they had us tracked the whole time.

Your description fits an AN/SQS 23 (which is obsolete and probably gone by now), an AN/SQS 26, or an AN/SQS 53. None of these have any reasonable chance of tracking divers.

A better choice would be one of the 87-72 kHz CTFM SONARS like the Straza 500 series. I seem to recall a version of this being designated AN/BQS 18, although it has been a while since I worked in that world.

 

[sinkorswim]

God help anyone if they get close enough to be hit by the navy's high-volume low and mid-frequency sonar, from what I have heard, it will pretty much turn your insides into gel. I know the Navy has restricted their use in peacetime. As far as I know the Navy doesn't have a sonar that can pick-up a diver, that is why they are using dophins to beat the living snot out them. Just think what kind of damage that a dolphin can do to someone if it hit you at full force. I sure wouldn't want to be on the receiving end.

 

[pipedope]

SQQ-14 would pick up a diver easily.

I seriously doubt that any are still around.
I did some operator time on one when I served on USS Constant (MSO-427) back in the 70s. I don't know all the details as I was the lead ET not ST but we were short crew being a reserve ship so we did a lot of doubling up.

If you had an MSO with SQQ-14 you could make a wonderful dive boat for wreck divers. The sonar makes finding wrecks easy. It was quite amazing how much you could see on the display.

 

[sinkorswim]

Now see what we did, since we started talking about it. Pride of the fleet.

http://story.news.yahoo.com/news?tmpl=story2&u=/ap/20050306/ap_on_re_us/stranded_dolphins