Re: Wztching for surface traffic (was: Submarine Movie? or TV?)

[Dick Morrisson <rmorrisson@unidial.com>]

Hi Mike,
It seems to me that a simple hydrophone would allow the sub pilot to hear the
boat, and listening for a moment would give a good idea of whether the boat
was approaching or leaving (just from the change in amplitude).  A more
sophisticated device might include a spectrum analyzer to pick off the
strongest signals and then some software to check the doppler shift (for
speed) as the boat approached or left.  As far as a frequency common to all
outboards, I would think they are all a function of rpm's.  For those of the
group with time in subs, can you hear boats approaching, and if so can you
determine direction, and/or approximate distance?  I know what it sounds like
to a diver (once the terror subsides) when a speed boat passes but I have no
experience in subs to relate (yet).
Dick Morrisson

Michael B Holt wrote:

> On Sun, 4 Jul 1999 15:57:26 EDT VBra676539@aol.com writes:
> >gotta have surface support, and the surface traffic doesn't have to be
> really
> >big to cause heart failure and the like--traffic in the Keys is like
> downtown
> >Miami only wetter, and that means somebody needs to pose as the RAM
> >vessel, fly the signals and man (staff?) the radio to shoo the tourists
> and
> >the boneheads and the just plain bastards off the sub's track.
>
> I've asked before about a device that would listen for a frequency common
> to all outboards, as a warning device for submarines.    It would be
> simple
> to build.
>
> Anyone ever heard of this?
>
> Michael B. Holt
> Oregon Hill, Richmond, Virginia, U.S.A.
> --
>
> ___________________________________________________________________
> Get the Internet just the way you want it.
> Free software, free e-mail, and free Internet access for a month!
> Try Juno Web: http://dl.www.juno.com/dynoget/tagj.