Re: acoustic imager

On 16/04/2025 09:01, Cursitor Doom wrote:

On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com>
wrote:
 

>
https://www.google.com/aclk?sa=L&ai=DChsSEwjTjaDVg9uMAxW3Hq0GHVmKOlYYACICCAEQARoCcHY&co=1&cce=2&sig=AOD64_3aGs74magNuXwdRGFo7oP8zK-LMQ&ctype=5&q=&adurl=

  For 42,000 dollars? There's a product there you could develop, John.

Yes, its expensive, but its a lot smaller than its predecessor from 1975
which "can be transported in a small estate car".
https://www.sciencedirect.com/science/article/abs/pii/0022460X76905526
I saw a composite visible light with overlaid acoustic image of the
exhaust of a flying jet aircraft at a talk by John Ffowcs-Williams
around 1976 or 1977.  I have not been able to find this image online,
but I think the work was done in collaboration with Rolls Royce.
What was notable - apart from the feat of acoustically imaging a
fast-moving aircraft, was that most of the noise came from a few
metres behind the jet engine in the turbulent exhaust.
John