sidescan with a pc soundcard?

[Joe]

Is it possable to make a basic side scan sonar
useing a pc with a good sound card eg. 24-bit/96 kHz or 44 kHz and maybe a booster amp for more output power,useing the computer to process the sound into realtime images?
There are already some programs that use sound cards as basic Oscilloscopes and Spectrum Analyzers
Any ideas?

[Joe]

Re: sidescan with a pc soundcard?

re previous posting I would like to make a further suggestion you could use a up conveter to get the sound card up to say 500kHz and a down converter to bring down the 500kHz to a frequency that a sound card can process normaly under 20kHz.
A up converter could consist of a ossilator at 485kHz this would be mixed with a 15kHz output from the sound card which would have been generated by the computer this would give two outputs one at (485-15) 470kHz and the other at (485+15) 500kHz .This signal could be then filtered with a 500kHz bandpass filter to remove the unwanted 470kHz signal,a down converter would work in reverse system bringing down the the received 500kHz to a useable 15kHz.
Any comments are welcome.

[Joe]

Anybody reading this know what I am talking about

In June I posted a message to this forum asking the question was it possible
to use a sound card to make a side sonar?
A lot of people read the post but I did not receive much in the way of
answers so I hope to get some answers WILL THIS WORK?
Please post If you know if this will work or otherwise I am not sure but I don't see why it will
not work
A average sound card usually works to 20 kHz I was proposing that you could use a up
converter to bring the frequency of the sound card up
to a higher frequency, a up converter is in this case would be a oscillator
running at say 190 kHz you would mix this sine wave with say a 10 kHz from
the sound card, this would give a output at 190 + and - 10 kHz i.e. 180 kHz and
200 kHz you would then use a band pass filter to filter out the unwanted
signals and say keep the 200 kHz signal which would be then further amplified and
sent to the transducer.A down converter would be used to reverse the
process,to bring the received echo at 200 kHz to 10 kHz so as the sound card
will be able to process it.
So the system I am proposing would consist as follows :
1 computer with soundcard
2 software to process the received data and transmit data
3 Up converter to convert the sound cards output signal to a higher
frequency say to 200 kHz
4 Down converter to convert down the received echo from the transducer to a
usable frequency say 10 kHz (could be housed with the transducer to improve
the signal to noise ratio)
5 Transducer say 200 kHz

The advantage of this system are:
1 The sound card does the digital to analog and analog to digital
conversion the heart of the sonar (at a low cost)
2 the system is broken down in to simple building blocks many people can
work together to design the various bits independently and test them
A. up down converters( basically very simple) ,B. software ,C. transducer
housing

What do you think of this theory?
I would like to hear from you.

[Carl]

Re: Anybody reading this know what I am talking about

I thought I had replied to your questions before - maybe it was email. I had concerns then but I think now it might work OK. You might be able to use std AM mod/demod components as most AM designs use 455kHz IF's.

- Carl

[dan]

Re: sidescan with a pc soundcard?

I am wondering if you got any further on the soundcard side scan idea. I saw a few replies but then it seemed like people lost interest. I did find a web site of some guy who seems to be working on software for this type of thing. The web address is http://www.pp.clinet.fi/~visitor/hasas/overview.html
Some system called Hasas, but I really didn't explore it too much. Anyhow I had the same idea, and found this mailing list, so I am wondering if anything has been done so far to further this idea.

Thanks
Dan



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