AVR-Chat

Actually, if this is mapping and you only need the first solid return, a
simple echosounder will do this for you.

Just measuring sound is not going to work as you could potentially be
picking up sound from all directions.

Sonar and echo sounders use a narrow beam which is pulsed on and off and you
listen for the return. The intensity of the reflection and time is used in
sonar. For echo sounder you simply listen for a reply above a preset level.
The frequency at which you transmit also determines the level of the return.
I worked in the North Sea with a 500Khz echo sounder and in one location we
got hardly any returns from the soft silty seabed. The 1Mhz scanning echo
sounder got great returns.

How is you mapping idea going to work?

Dave...

-----Original Message-----
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of Jim Wagner
Sent: 25 August 2011 09:53
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] Re: sound measurement

If you are "mapping", then you are probably talking about sonar, which
requires a transmitter and receiver, and a measured time delay for the echo.
This is very different from just measuring "sound amplitude".

Jim Wagner
Oregon Research Electronics

On Aug 24, 2011, at 6:58 PM, blue_eagle wrote:

> I wanted to try audio range and up to about 125KHz range. This is for 
> lake mapping. I could buy one but just want to make one and learn at 
> the same time.
>
> Brian
>
> --- In AVR-Chat@yahoogroups.com, Jim Wagner <wagnerj@...> wrote:
> >
> > What frequency range?
> >
> > Jim Wagner
> >
> > On Aug 20, 2011, at 8:05 PM, blue_eagle wrote:
> >
> > > I havent picked an avr chip yet. What I want to do is measure the 
> > > sound underwater from two microphones to find out which one has
> more
> > > sound over the other. Trying to understand how to use the micro to 
> > > average sound inputs. How often should it sample? Do you have a 
> > > website to explaine it?
> > >
> > > Thanks,
> > > Brian
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> 



[Non-text portions of this message have been removed]



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