[PSUBS-MAILIST] passive sonar

Sat May 18 15:23:41 EDT 2019

Brian,

Since you are depending on the surface vessel to see you with its equipment there may not be much that you can do.  Most fish finders would likely paint your shape proud off the bottom, and maybe as a big fish while in the water column. Unless other have had experience with that scenario, trials would answer those questions.

It would be interesting to see how an upward pointing transducer on your sub would be detected and painted by a surface based depth sounder. Would your signal not "jam" the other's display?  It's worth a try.

Tim

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of Brian Cox via Personal_Submersibles
Sent: Saturday, May 18, 2019 10:26 AM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] passive sonar

Tim,  

                       Yes that's the idea.   On my Garmin depth finder there is an optional screen which is simply stationary screen and then there is the screen that is moving , which gives you a "history" of the last few seconds of scanning .  But it would be interesting to play around with the detect ability of something like that.   Not sure how practical it would ultimately be.  

Brian

--- personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org>  wrote:

From: T Novak via Personal_Submersibles <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
To: "'Personal Submersibles General Discussion'" <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
Subject: Re: [PSUBS-MAILIST] passive sonar
Date: Sat, 18 May 2019 07:15:35 -0700

Brian,

What are you trying to do with the "passive sonar" that you are considering? Are you wanting to make your submarine more easily detectable by a surface boat with a depth sounder?

Tim

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of Brian Cox via Personal_Submersibles
Sent: Friday, May 17, 2019 8:35 PM
To: PSubs <personal_submersibles at psubs.org <mailto:personal_submersibles at psubs.org> >
Subject: [PSUBS-MAILIST] passive sonar

        I've been thinking about some sort of pinger locator for my sub.  I may get a commercially available one just as an extra safety measure, but in the mean time I was playing around with my depth finder on my sailboat .  I was thinking if I had a rotating disk that would be a little higher than the sub the changing surface exposure to the sonar waves would appear on the depth finder as a recurring blip .  I tried it with a radar reflector that I have, I tied it to a line and located it just below my transducer, I was able to move it around and observe the display on the screen.   Since the radar reflector ( used on boats so big ships can see you) has all these sides to it, as I moved it around it would show up intermittently since the sound wave sometimes would not bounce back.  I think a flat surface rotated so only the edge is showing and then a large surface was showing at a regular intervals could work as an indicator.   I might be especially valuable if you were blending into the bottom so much as to not be detectable .  That way someone with just an ordinary depth finder could detect you.  

Brian    

_______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20190518/f34902d9/attachment.html>