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Awesome, I nominate you for a Psub award.
Probably the one you had last time.
Alan
----- Original Message -----
Sent: Wednesday, December 01, 2010 11:53
PM
Subject: RE: [PSUBS-MAILIST] directional
passive sonar has arrived!
Alan,
In in-water tests of the six
hydrophone array using a micro switch hydrophone selector in 2007, ranges to
small pleasure craft with gas engines with low horse power (<25) was over
1/2 mile and this was in a lake containing many branching outcrops. The lake
had underwater trees and mud that absorbed and scattered sound. In open
water the detection of similar craft could be several miles.
In this same lake boats with electric drive trolling motors were easily heard
1/4 of a mile.
I'll see if I can retrieve the actual in-water
test reports from this outing.
The hydrophones in use today
differ little from these very ones used during this test.
David
Bartsch
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject:
Re: [PSUBS-MAILIST] directional passive sonar has arrived!
Date: Wed, 1 Dec
2010 22:50:47 +1300
David,
You previously mentioned tracking a submarine from a
boat with this system.
That sounds great, what range do you anticipate it would
have ???
I presume if you have your receivers even further apart
then the direction would be easier to pick up.
Alan
Sent: Wednesday, December 01, 2010 9:24
PM
Subject: RE: [PSUBS-MAILIST]
directional passive sonar has arrived!
Alan,
Before this system (although
it has yet to be better refined) a grid search was all that a surface craft
could do to locate a disabled submarine equipped with a distress pinger. Now
with this system deployed aboard the surface support vessel, no grid search
would be required but simply the training of this sonar onto the source of
this transmission!
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
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