https://www.google.com/aclk?sa=L&ai=DChsSEwjTjaDVg9uMAxW3Hq0GHVmKOlYYACICCAEQARoCcHY&co=1&cce=2&sig=AOD64_3aGs74magNuXwdRGFo7oP8zK-LMQ&ctype=5&q=&adurl=
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.
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an
FPGA, and some code.
I'd expect to see a Chinese version on Temu soon.
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an
FPGA, and some code.
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an
FPGA, and some code.
In the last few decades, there's been a lot of work done on imaging with >sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good
image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array,
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in
integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1 >components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course.
If one is willing to trade off SNR and computational expense, you can
get the resolution of a full array with far less than N**2 antennas--I
forget what the the number is, but it's a lot more like N log N than
N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on
that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better
than one might suppose.
Cheers
Phil Hobbs
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.
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>LMQ&ctype=5&q=&adurl=
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-
For 42,000 dollars? There's a product there you could develop, John.
It's only $19,998.99 from Fluke: <https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905>
That might have been the price from before the tariffs arrived: "Ships
from supplier. Expected to arrive on or before Tue. May 06." "Country of Origin: China (subject to change)"
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
It's only $19,998.99 from Fluke:
<https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905>
That might have been the price from before the tariffs arrived:
"Ships from supplier. Expected to arrive on or before Tue. May 06."
"Country of Origin: China (subject to change)"
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an
FPGA, and some code.
In the last few decades, there's been a lot of work done on imaging with >>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good
image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array,
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in
integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1
components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course.
If one is willing to trade off SNR and computational expense, you can
get the resolution of a full array with far less than N**2 antennas--I
forget what the the number is, but it's a lot more like N log N than
N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on
that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better
than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those
hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the
world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example: https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an
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. >>>>>
FPGA, and some code.
In the last few decades, there's been a lot of work done on imaging with >>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good
image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array,
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in
integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>> components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course.
If one is willing to trade off SNR and computational expense, you can
get the resolution of a full array with far less than N**2 antennas--I >>>> forget what the the number is, but it's a lot more like N log N than
N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on
that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those
hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the
world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>> FPGA, and some code.
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. >>>>>>
In the last few decades, there's been a lot of work done on imaging with >>>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>> image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>> components, i.e. essentially the same information as every other
adjacent pair.ÿ The redundancy is less at wider spacing, of course.
If one is willing to trade off SNR and computational expense, you can >>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>> forget what the the number is, but it's a lot more like N log N than >>>>> N**2.ÿ A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those
hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>> world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is.ÿ Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>> FPGA, and some code.
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. >>>>>>
In the last few decades, there's been a lot of work done on imaging with >>>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>> image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>> components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course. >>>>>
If one is willing to trade off SNR and computational expense, you can >>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>> forget what the the number is, but it's a lot more like N log N than >>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those
hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>> world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
Cursitor Doom <cd@notformail.com> wrote:
bistatic radar" > For example: > >>https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basi >>cpage/20171219/Session%201.0.pdf > > > John >
For a long time, too. IIRC the first successful radar experiment used
the reflection from a BBC transmitter.
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
Yeah, Auntie was useful for something back then.
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>> FPGA, and some code.
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. >>>>>>
In the last few decades, there's been a lot of work done on imaging with >>>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>> image, you need spatial frequency information corresponding to all
values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense
array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>> components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course.
If one is willing to trade off SNR and computational expense, you can >>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>> forget what the the number is, but it's a lot more like N log N than >>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those
hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>> world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs >><pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>> FPGA, and some code.
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. >>>>>>>
In the last few decades, there's been a lot of work done on imaging with >>>>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>>> image, you need spatial frequency information corresponding to all >>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>> components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>> world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Cursitor Doom <cd@notformail.com> wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>> FPGA, and some code.
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. >>>>>>>
In the last few decades, there's been a lot of work done on imaging with >>>>>> sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>>> image, you need spatial frequency information corresponding to all >>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>> components, i.e. essentially the same information as every other
adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>> world would have the same effect, see everything. Radar without the
transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
Yes but until the cavity magnetron came to fruition British radar was >technically grossly inferior to German radar. Think of the wurzburg system >with uhf, parabolic dishes, high prf rates, coax cable etc.
In the early stages the main factor was operational in that the brits >thoroughly integrated radar into air defense whilst the Germans only used
it on an individual basis. The chain home radar was so totally >different/primitive/worse than the Nazis radars that initially they mistook >it for something else.
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com> >>wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs >>><pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>>> FPGA, and some code.
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. >>>>>>>>
In the last few decades, there's been a lot of work done on imaging with
sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>>>> image, you need spatial frequency information corresponding to all >>>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>>> components, i.e. essentially the same information as every other >>>>>>> adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>>> world would have the same effect, see everything. Radar without the >>>>>> transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a >>>>BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Pearl Harbor and 9/11 were both curiously 'fortuitous' incidents in
that they galvanized public support for going to war.The gullible
masses are *so* easily influenced (and not just in America).
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>>> wrote:
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
On Fri, 18 Apr 2025 21:58:25 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com>Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>>>> FPGA, and some code.
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. >>>>>>>>>
In the last few decades, there's been a lot of work done on imaging with
sparse arrays.
A full NxN rectangular antenna array has an enormous amount of >>>>>>>> duplicated information from an imaging point of view. To make a good >>>>>>>> image, you need spatial frequency information corresponding to all >>>>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>>>> components, i.e. essentially the same information as every other >>>>>>>> adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better
than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>>>> world would have the same effect, see everything. Radar without the >>>>>>> transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a >>>>> BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Pearl Harbor and 9/11 were both curiously 'fortuitous' incidents in
that they galvanized public support for going to war.The gullible
masses are *so* easily influenced (and not just in America).
Yes, those deplorable gullible masses are brave and patriotic. The Ivy
League elites know better.
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com> >>>>>>>>> wrote:Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>>> FPGA, and some code.
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. >>>>>>>>
In the last few decades, there's been a lot of work done on imaging with
sparse arrays.
A full NxN rectangular antenna array has an enormous amount of
duplicated information from an imaging point of view. To make a good >>>>>>> image, you need spatial frequency information corresponding to all >>>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>>> components, i.e. essentially the same information as every other >>>>>>> adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better >>>>>>> than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>>> world would have the same effect, see everything. Radar without the >>>>>> transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a
BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Pearl Harbor and 9/11 were both curiously 'fortuitous' incidents in
that they galvanized public support for going to war.The gullible
masses are *so* easily influenced (and not just in America).
On Fri, 18 Apr 2025 21:58:25 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com> >>wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com> >>>wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs >>>><pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com> >>>>>>>>> wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com>Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>>>> FPGA, and some code.
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. >>>>>>>>>
In the last few decades, there's been a lot of work done on imaging with
sparse arrays.
A full NxN rectangular antenna array has an enormous amount of >>>>>>>> duplicated information from an imaging point of view. To make a good >>>>>>>> image, you need spatial frequency information corresponding to all >>>>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1 >>>>>>>> components, i.e. essentially the same information as every other >>>>>>>> adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>>>> get the resolution of a full array with far less than N**2 antennas--I >>>>>>>> forget what the the number is, but it's a lot more like N log N than >>>>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better
than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>>>> world would have the same effect, see everything. Radar without the >>>>>>> transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a >>>>>BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a
bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Pearl Harbor and 9/11 were both curiously 'fortuitous' incidents in
that they galvanized public support for going to war.The gullible
masses are *so* easily influenced (and not just in America).
Yes, those deplorable gullible masses are brave and patriotic. The Ivy
League elites know better.
On Fri, 18 Apr 2025 19:18:25 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 21:58:25 +0100, Cursitor Doom <cd@notformail.com> >>wrote:
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com> >>>wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com> >>>>wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs >>>>><pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
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.
Seems like it needs maybe a dozen electret mikes, one mux'd ADC, an >>>>>>>>>> FPGA, and some code.
In the last few decades, there's been a lot of work done on imaging with
sparse arrays.
A full NxN rectangular antenna array has an enormous amount of >>>>>>>>> duplicated information from an imaging point of view. To make a good >>>>>>>>> image, you need spatial frequency information corresponding to all >>>>>>>>> values of dx and dy, with some regular spacing, i.e. in an NxN array, >>>>>>>>>
dx and dy go from -N/2 to +N/2-1 (or equivalently, from 0 to N-1) in >>>>>>>>> integer steps.
In principle you only need one estimate per spacing, but in a dense >>>>>>>>> array, every pair of adjacent pixels gives an estimate of the dx = +-1
components, i.e. essentially the same information as every other >>>>>>>>> adjacent pair. The redundancy is less at wider spacing, of course. >>>>>>>>>
If one is willing to trade off SNR and computational expense, you can >>>>>>>>> get the resolution of a full array with far less than N**2 antennas--I
forget what the the number is, but it's a lot more like N log N than >>>>>>>>> N**2. A pal of mine in grad school, Yoram Bresler, did his thesis on >>>>>>>>> that problem, which is where I first heard of it.
So a sparse array of microphones can in principle do quite a bit better
than one might suppose.
And it looks like the Fluke acoustic imaging is primitive, like those >>>>>>>> hybrid visual+thermal gadgets.
Cheers
Phil Hobbs
I'd expect that a bunch of wideband antennas and ADCs listening to the >>>>>>>> world would have the same effect, see everything. Radar without the >>>>>>>> transmitter. No doubt that is being done.
It is. Look up "passive bistatic radar"
For example:
https://sspd.eng.ed.ac.uk/sites/sspd.eng.ed.ac.uk/files/attachments/basicpage/20171219/Session%201.0.pdf
John
For a long time, too.
IIRC the first successful radar experiment used the reflection from a >>>>>>BBC transmitter.
Cheers
Phil Hobbs
Radar and code-breaking really saved Britain's bacon in WW2. Plus a >>>>>bit of assistance from the old colonies. :->
The Brits are very lucky that the Pearl Harbor attack happened.
Pearl Harbor and 9/11 were both curiously 'fortuitous' incidents in
that they galvanized public support for going to war.The gullible
masses are *so* easily influenced (and not just in America).
Yes, those deplorable gullible masses are brave and patriotic. The Ivy >>League elites know better.
Same with royalty. The kings and queens of old would be at the
forefront of every battle til they either vanquished the foe or else
got killed trying. Funny how that turned around in recent centuries. I
can just imagine King Charles running a mile at the first hint of any
serious trouble.
On Sat, 19 Apr 2025 11:23:19 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 19:18:25 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 21:58:25 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Fri, 18 Apr 2025 12:50:59 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Fri, 18 Apr 2025 18:04:47 +0100, Cursitor Doom <cd@notformail.com> >>>>> wrote:
On Fri, 18 Apr 2025 10:34:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-17 03:45, John R Walliker wrote:
On 17/04/2025 03:12, john larkin wrote:
On Wed, 16 Apr 2025 22:01:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2025-04-16 10:41, john larkin wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>
wrote:
On Tue, 15 Apr 2025 15:04:15 -0700, john larkin <jl@glen--canyon.com>
wrote:
Yes, those deplorable gullible masses are brave and patriotic. The Ivy
League elites know better.
Same with royalty. The kings and queens of old would be at the
forefront of every battle til they either vanquished the foe or else
got killed trying. Funny how that turned around in recent centuries. I
can just imagine King Charles running a mile at the first hint of any
serious trouble.
It impresses me how much material well-being we have now, given that
we generously fund a huge class of highly paid parasites.
On Thu, 17 Apr 2025 11:30:27 -0700, Jeff Liebermann wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>LMQ&ctype=5&q=&adurl=
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-
For 42,000 dollars? There's a product there you could develop, John.
It's only $19,998.99 from Fluke:
<https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905>
That might have been the price from before the tariffs arrived: "Ships
from supplier. Expected to arrive on or before Tue. May 06." "Country of
Origin: China (subject to change)"
Wrong model, the ii905 is missing some software features:
https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii915
Has all functions for $25k, in stock.
Bruel & Kjaer has been providing systems for acoustic imaging for decades,
a similar handheld system to the Fluke:
<https://media.hbkworld.com/m/be462d448ae9553b/original/BK-Connect- >Acoustic-Camera-Datasheet-bp2534.pdf>
Quite a bit more capable but probably not quite so cheap.
On Thu, 17 Apr 2025 19:48:49 GMT, Glen Walpert <nospam@null.void>
wrote:
On Thu, 17 Apr 2025 11:30:27 -0700, Jeff Liebermann wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>LMQ&ctype=5&q=&adurl=
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-
For 42,000 dollars? There's a product there you could develop, John.
It's only $19,998.99 from Fluke:
<https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905>
That might have been the price from before the tariffs arrived: "Ships
from supplier. Expected to arrive on or before Tue. May 06." "Country of >>> Origin: China (subject to change)"
Wrong model, the ii905 is missing some software features:
https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii915
Has all functions for $25k, in stock.
Thanks. I missed that they were difference model numbers. Video
explains a few differences:
"Comparing the Fluke ‘SEE-Sound’ ii500, ii905, and ii915 Acoustic
Imagers"
<https://www.youtube.com/watch?v=br5hhjm5Aqo> (1:56)
Fluke acoustic imager pages: ><https://www.fluke.com/en-us/products/industrial-imaging> ><https://www.fluke.com/en-us/search/fluke?query=ii900&facets=videos_en_us%2Cproducts_and_kits_en_us%2Cproduct_accessories_en_us&product_categories=Industrial%20imaging>
Bruel & Kjaer has been providing systems for acoustic imaging for decades, >>a similar handheld system to the Fluke:
<https://media.hbkworld.com/m/be462d448ae9553b/original/BK-Connect- >>Acoustic-Camera-Datasheet-bp2534.pdf>
Quite a bit more capable but probably not quite so cheap.
Cheap? I can't afford any of them. I'm still saving my pennies for
an IR camera.
On Thu, 17 Apr 2025 19:48:49 GMT, Glen Walpert <nospam@null.void>query=ii900&facets=videos_en_us%2Cproducts_and_kits_en_us%2Cproduct_accessories_en_us&product_categories=Industrial%20imaging>
wrote:
On Thu, 17 Apr 2025 11:30:27 -0700, Jeff Liebermann wrote:
On Wed, 16 Apr 2025 09:01:00 +0100, Cursitor Doom <cd@notformail.com>LMQ&ctype=5&q=&adurl=
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-
For 42,000 dollars? There's a product there you could develop, John.
It's only $19,998.99 from Fluke:
<https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905>
That might have been the price from before the tariffs arrived: "Ships
from supplier. Expected to arrive on or before Tue. May 06." "Country
of Origin: China (subject to change)"
Wrong model, the ii905 is missing some software features:
https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii915
Has all functions for $25k, in stock.
Thanks. I missed that they were difference model numbers. Video
explains a few differences:
"Comparing the Fluke ‘SEE-Sound’ ii500, ii905, and ii915 Acoustic
Imagers"
<https://www.youtube.com/watch?v=br5hhjm5Aqo> (1:56)
Fluke acoustic imager pages: <https://www.fluke.com/en-us/products/industrial-imaging> <https://www.fluke.com/en-us/search/fluke?
Bruel & Kjaer has been providing systems for acoustic imaging for
decades,
a similar handheld system to the Fluke:
<https://media.hbkworld.com/m/be462d448ae9553b/original/BK-Connect- >>Acoustic-Camera-Datasheet-bp2534.pdf>
Quite a bit more capable but probably not quite so cheap.
Cheap? I can't afford any of them. I'm still saving my pennies for an
IR camera.
Drivel: I just blew up my ancient Delcon (HP) 4905A Ultrasonic
Translator detector. <https://vtda.org/pubs/HP_Journal/HP_Journal_1967-05.pdf>
It works well enough for my limited purposes, but rather than trying to repair it (again), I was thinking about buying a shiny new replacement
or building my own: <https://navat.substack.com/p/diy-acoustic-camera-using-uma-16>
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