Re: A sub question

["Alan D. Secor" <secor@btv.ibm.com>]

>Alan D. Secor wrote:
>
>> I hope everyone who is considering a positively buoyant design such as
>> "Deep Flight" keeps in mind that since forward motion is required to
>> stay submerged, then water visibility plays a MAJOR factor in this type
>> of design.  I would hate to have to sustain a 2-3 mph forward velocity
>> to remain submerged in some of the lakes around here!!
>
>I have thought about this a bit. I think a wise investment would be to
>have some type of sonar scanner pointed straight ahead, hooked up to an
>alarm system. Anything solid enough to do pressure-hull damage should
>show up with a sonar profile. I'd probably use a small single-board
>computer to do the sonar analysis, and use a fairly wide beam low
>frequency sonar to get decent coverage.
>
>AUVs have exactly the same problem to deal with, except they must rely
>soley on sonar information for collision avoidance. Of course, the
>stakes are somewhat lower for an AUV versus a person's life, but it is
>still the same problem that has to be solved.
>
>It also wouldn't hurt to have some powerful lights mounted, pointing
>forward.
>
>Later,
>Jon
>
>-----------------------------------------------------------
> Jon Hylands      Jon@huv.com      http://www.huv.com/jon
>
>Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
>         http://www.huv.com
>
>
AUVs have the same problem BUT are they positively buoyant?  I imagine 
they
can stop or go slow to avoid an object without floating to the surface.

Also WRT powerful lights....remember that in a low vis situation there is
usually a lot of particulate matter suspended in the water making 
backscatter
from the light a problem.  Mounting the lights at a 45 deg angle from 
direction
of viewing would help to reduce this somewhat.

Later.......Al

--
Alan D. Secor
e-mail: secor@btv.ibm.com