Re: [PSUBS-MAILIST] Re: SONAR

["Matt Cadieux" <compkid15@earthlink.net>]

In order for a sonar to work it has to "hit" against something and bounce
back so an upward facing sonar would only give you readings if you were
under something.  SO it would only really be good to check when your
surfacing to make sure that your not coming up under a boat other then that
it would give no reading.
----- Original Message -----
From: "Ed Greany" <crest25@attglobal.net>
To: <personal_submersibles@psubs.org>
Sent: Saturday, August 11, 2001 3:13 PM
Subject: Re: [PSUBS-MAILIST] Re: SONAR


> Good question. The answer is no, now unless they are both on the same
> frequency.
> The received is tuned to receive a certain frequency (range) and it is
> listening for its own bounce.
> It's like two radio operators standing next to each other talking to
> someone on the other end. The two radios do not mix and confuse the
> receivers.
>
> Ed
>
> Michael B. Holt wrote:
> >
> > What problems appear if one uses TWO fishfinders: one pointed down to
> > give distance below the keel and one pointed up to give distance to
> > the surface?  Would the two interact to produce false readings?
> >
> > Mike
>