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Technical article on sonar technology

Old 11-23-2017, 07:23 AM
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Default Technical article on sonar technology

If you are interested in the technical aspects of fish finder sonar technology, I found an article with loads of info.


The article has lots of simple math, but it is well done. It has good explanations of transducer function, standard, CHIRP and side scan sonar.

There will not be a quiz later!

Last edited by m9000; 11-23-2017 at 11:34 AM. Reason: typo
Old 11-23-2017, 09:28 AM
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Default Informative and Worthwhile

Thanks, very useful.
Old 11-23-2017, 09:58 AM
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outstanding. I might argue this one, however:

Your depth finder puts out a constant amount of power. "

Pulse length has traditionaly been adjustable, at least on non CHIRP systems. That affects directly power to the target. And, many sounders do adjust power as a function of the depth range they are on. Again, not sure what CHIRP sounders do here.

while I'm thinking about Watts and power, and this paper.

RMS Power is not a proper mathmatical representation of power. You can do root-mean-square of Volts and Amps, but not power. If engine manufacturers played this same game with cars, they would be called out on it. A 600W depthfinder can deliver this 600Watts for a few milliseconds. If you bought a 300 HP car, and found out that the engine could only deliver that power for a fraction of a second, you would be dissapointed.

Sonar shares this power issue with radar systems. There, it is acceptable to indicate peak transmit power. So, you have a 12kW radar that can put out that amount of power for a very short amount of time. Radars don't, or shouldn't, be specing "rms power".

So, sonar guys: It's peak power with an associated pulse length. RMS power is unmeasurable and nonsensical.

Last edited by diver dave; 11-23-2017 at 12:12 PM.

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