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RE: [PSUBS-MAILIST] directional passive sonar has arrived!

Alan,
 
   In it's present state, installation aboard a surface support vessel or perhaps an ambient submarine is all we could hope for. This is because this array must be physically turned in that a shaft with hull penetration is required if installed aboard a 1atm submarine. With an ambient sub, this array would simply be lowered out of the access hole in the boats underbelly or over the side of a surface boat.
Flow noise if deployed while in transit will be a problem as this system was used in a sprint and drift method of search in WW1.
   If deployed from a surface unit, following a submarine should not be hard as motor function and other transients should be easily detected especially the use of pressurized air.
   It is a diamond in the rough but shows great potential.
 
David Bartsch
 
 
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] directional passive sonar has arrived!
Date: Mon, 29 Nov 2010 21:04:45 +1300

David,
You could possibly use this to conduct grid searches.
You could have a surface boat with GPS tracking a certain course, & the sub on the bottom
following sounds emitted from the surface craft.
Alan
----- Original Message -----
Sent: Monday, November 29, 2010 7:20 PM
Subject: RE: [PSUBS-MAILIST] directional passive sonar has arrived!

   I was using the Sierra 1 rc Bismarck and the range was 200' at the farthest. Normal boat traffic will no doubt be picked up much farther. It does get flaky when the range is less than 20' but farther out it's great. If I add the analog meter circuit this should get this to within 1 to 3 degrees! The farther out from the array the more accurate the results.
   The next logical step is for Jens to come up with a time delay circuit whereby three fix mounted hydrophones at the base of a K250/350 can determine the actual bearing with beam forming as apposed to turning an actual array. This is where we intend to go with this.
   There are some bugs to work out. The need for shielding of signal wires came in loud and clear as I once again heard radio stations...when I ran the rc boat I almost went deaf!
   It's like when "skunk works" found what shape best evaded radar. Once discovered, they were handed it back and told to find a way to make it fly...
   We have a passive sonar that can show the bearings of detected contacts. All we need now is a simple way to install and use on these small submarines. We have our work cut out for us.
   I was very impressed with this first in-water test of this system.
  
 
David Bartsch
 
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] directional passive sonar has arrived!
Date: Mon, 29 Nov 2010 17:40:55 +1300

Keep at it David sounds great.
I guess you now have the added security that you will be able to tell
what direction the crocodiles comming from. (Lake Placid movie)
Alan
----- Original Message -----
Sent: Monday, November 29, 2010 3:09 PM
Subject: [PSUBS-MAILIST] directional passive sonar has arrived!

To all:
 
  I just tested the passive binaural sonar system in the waters of Lake Placid in Chickasaw State Park just East of Henderson, Tn. today. This system can determine the exact bearing to a given detected passive sonar contact within about 5 degrees and should prove even more accurate once an analog meter system is deployed.
  There are still a few issues to work out such as proper shielding to avoid radio reception and better sound mounting to avoid self generated noise.
 
  Passive directional sonar has finally arrived!
 
David Bartsch