[Scott Dorsey]

wrote:
I'm wondering what his interest is, whether he's just dabbling or he has an
academic interest of some sort. IF the later I'd think he'd
have already cracked a book or two on the subject.

There is an outrageous amount of information on the subject in open
publications from the US Navy. A lot of it has to do with very fancy
propeller designs. Expensive propeller designs, mind you, which is
why you don't see them on merchant marine vessels.

The Navy wants to build ships that aren't audible on passive sonar
receivers. Incidentally, some of the problem with building very quiet
ships is that animals run into them.

Some of the film sound guys who do underwater
shoots might be able to address it a little more
intelligently than a bunch of live sound and studio rats,
but still, i'd say the oceanographers and others might know
a bit more on the subject. Here in this group most of us
have a better grasp of acoustic characteristics of air

It's amazing how the physics are the same. The reason I got interested in
it is because almost all of the research on large phased array microphone
systems is Navy-financed stuff. Beamforming in air is really interesting and
a lot of the ocean work can be applied to it.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."