Next message: Arild Jensen: "RE: lv-ab: "Prper Watch""
Why not just go LIDAR?
On Thu, 1 Jun 2006 20:41:52 -0400
"lavida" <> wrote:
> Perhaps infrared detection??
>
> -----Original Message-----
>From:
> [mailto:] On
>Behalf Of Ken James
> Sent: Thursday, June 01, 2006 7:09 PM
> To: ; Philip
> Subject: Re: lv-ab: "Prper Watch"
>
>
> As far as watch keeping aids are concerned I would think
>that a passive
> sonar unit would be just the ticket. Sound travels
>faster and further
> underwater than in the air and a ship of fishing vessel
>would be audible
> for some distance.
>
>
>
> Any one hear of such a thing for small boats?
> Reply;
> In fact, at one time I had a financial backer who was
>interested in just
> such a device. However I am convinced it is a very tough
>technical
> problem if you use just one mic or sensor. This is
>because sound is
> distorted so much through water, you may hear a ship 20
>nm away clearly
> but not the one right next to you. An array of sensors
>at different
> depths would be needed.
> Or it may be possible to link a net of sensors
>electronically.
>
> I also served in the USN on Destroyers. One of our main
>jobs was hunting
> subs. Our sonar was state of the art, but when it came
>to detecting
> surface ships, it was nowhere near reliable, it would
>sooner or later
> but when was a question and getting accurate range could
>be a problem.
> Of course the same was true for subs, even though the
>sonar dome had
> many sensors. But we did a search pattern and did it
>over and over if
> necessary, as well as deploying both radio drop sones
>from a helo that
> would go to different depts and towing a powerful array
>at different
> depths. With all of that in action and also links to
>other ships and
> underwater listening stations we could detect subs
>before they could
> detect us...most of the time.
>
> Of course a sailboat can't do all that. So in other
>words yes it could
> be done but the answer is not simple or cheap.-Ken
>
>
>
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