RE: [PSUBS-MAILIST] Re: SONAR

["Karl S. Luttrell" <SDECO@prodigy.net>]

Sonar industry calls transducers for measurement to surface or bottom
altimeters.  See www.simrad.ca and click on offshore products to see types
of altimeters they offer.

Output can be variable voltage (0-5v or 0-10v, e.g.) or current at a
constant voltage (4-20ma, e.g.) or digital.  With the voltage or current
types, all you have to do is recalibrate a voltage or current meter to read
depth to surface or bottom.  Digital can be whatever you program the output
to read.  On ROVs they are usually fed to the OSD (On Screen Display)
interface computer for a constant readout on the video monitor.  Same
readout often used for pressure transducer type depth meter, compass rose,
date/time, umbilical payout, etc.

Picies box was ROV standard OSD for a while.  Nobody liked them much, but
they usually got the job done.  Newer OSDs are much more input friendly and
trend to digital allows greater connectivity. They are easier to program for
the display pattern over the video that the user wants.  Used to have to
build separate adapters for Hall effect (magnetic) sending units.  Newer
OSDs can handle those without adapter upstream.

SciDiver



-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org]On Behalf Of
VBra676539@aol.com
Sent: Monday, August 13, 2001 4:28 AM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Re: SONAR


In a message dated 8/12/2001 11:16:09 PM Eastern Daylight Time,
crest25@attglobal.net writes:

<< Yep, you're correct. Sonar will bounce or deflect with a change in
 medium or gradient temperature layer. I didn't comment about it bouncing
 or now off the surface since I have never tried that. I only know about
 signals going down or out from the vessel.
  >>
It will bounce off the surface very nicely--makes a nice depth gauge if
you've got a transducer you can point up--I've got one mounted on the front
of my stbd side thruster for instance.
Vance