Derek Lyons wrote:

I'm sure you do. But where do I state that the underwater sonar
operated in the ultrasonic range?

Since every message you've written has dealth with ultrasonics..

Given that Pat's original question was about cameras with
ultrasonic range finders, that shouldn't be too surprising.

What else could you possibly mean?

I could have meant what I wrote: The EM wave/acoustics analog can often
be exploited when the wavelengths are similar and that I have direct
knowledge of people who have very successfully done so.

Practical EM waves have wavelengths ranging from 1000's of metres to
1/1000 of a metre. That's a fairly broad range. I haven't done any
work in underwater acoustics (my expertise includes RCS prediction,
modification, and measurement at microwave frequencies) but would hazard
a guess that underwater sonar wavelengths likely fall within that broad
range.

Ah, once again you resort to flame and insult....

In hindsight, I admit that I shouldn't have explicitly paraphrased your
earlier dismissive responses to Pat and others when I responded to you.

--
Dave Michelson