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Finding the Air Cannon

125 pointsby mikecarltonover 1 year ago

15 comments

mdipover 1 year ago
This is a clever approach and it got me wondering a few things.<p>An hour or so from where I live there have been complaints about an infrequent low rumbling sound for <i>years</i>[0]. I&#x27;d wondered -- at the time -- why you couldn&#x27;t just do something like they do with the gunshot detectors to find the source of the sound[1]. I suspect there must be a technical&#x2F;physics reason that I am not familiar with. This article re-enforced that thinking for me -- I think I&#x27;ve heard one of these air cannons, before (I have not heard the Windsor Hum), and its characteristics seem more like a gunshot kind of sound than what&#x27;s described here but ... if you can record the time it starts from three different points (and all you&#x27;re looking for is &quot;an area roughly the size of a large factory&quot; because it had always been suspected to be one of the plants along the river), wouldn&#x27;t this approach have been simple&#x2F;cheap enough to do to figure it out[2]?<p>[0] <a href="https:&#x2F;&#x2F;www.npr.org&#x2F;2020&#x2F;08&#x2F;04&#x2F;898853311&#x2F;it-took-a-pandemic-mystery-of-windsor-hum-is-solved" rel="nofollow">https:&#x2F;&#x2F;www.npr.org&#x2F;2020&#x2F;08&#x2F;04&#x2F;898853311&#x2F;it-took-a-pandemic-...</a> -- it was solved because a steel plant shut down and the problem went away.<p>[1] Part of the problem was that a subset of the population could hear it and a subset of that population noticed it enough to be bothered about it so it kind of led to a large number of people dismissing complaints as &quot;people who complain about WiFi signals harming their health&quot;<p>[2] And if I answer my own question: I suspect it probably was and I suspect the reason it wasn&#x27;t done is that nobody cared enough to do it, really. :)
gwernover 1 year ago
Fun historical trivia: shortly after winning the Nobel Prize, Bragg <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Lawrence_Bragg#Work_on_sound_ranging" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Lawrence_Bragg#Work_on_sound_r...</a> spent WWI working on exactly this problem <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Artillery_sound_ranging" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Artillery_sound_ranging</a>
efitzover 1 year ago
I really like the usage here. I would love to generalize the app to find people hunting and setting off fireworks at impolite times.<p>Why did you use pixels on a map image for location, instead of GPS? Phones have GPS these days. You could have a simple app where you push the button when you hear the noise, it reports to a cloud function, and instantly triangulates and throws a point on your favorite map program.
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NotYourLawyerover 1 year ago
I was thinking that you’d need a pretty accurate clock reference to do this, automatically triggering based on a microphone to log the time.<p>But I guess not. Sound is slow on a distance scale of miles, so timing it to the nearest second is good enough.
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mixedmathover 1 year ago
This is an unexpected programming application. It&#x27;s nice that the farmer actually changed behavior after receiving the phone call.<p>At first, I thought there was a clear improvement. This problem essentially boils down to finding the intersection point of three circles. But it&#x27;s also likely that with the small fuzz from imprecise time measurement that the three measured circles wouldn&#x27;t actually intersect. I would guess that a small boost could be achieved by sampling points near the two intersection points of any two circles, but this is moot when it&#x27;s just possible to brute force the whole grid.
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gorkishover 1 year ago
&gt; Twenty minutes later, he called back reaffirming they are not running their cannons at night. He also assured me that their air cannons could not be heard more than a mile away.<p>This is the point at which I would have changed my attitude to the situation quite dramatically. Given the opportunity to own up and simply apologize and fix the issue, the fellow just went full lie-to-your-face mode. What in the everloving heck is wrong with people?
DylanSpover 1 year ago
I&#x27;m curious if regularly firing these cannons on a schedule actually works to scare the geese away. When reading about the accident of Ural Airlines Flight 178 [1], the airport had air cannons for scaring off birds, but they fired them on a regular schedule instead of in response to particular flocks, and the local birds just got used to it. I don&#x27;t know if the circumstances are similar enough for that to apply with these farms and birds, though.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ural_Airlines_Flight_178" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Ural_Airlines_Flight_178</a>. There&#x27;s a good article about the accident at <a href="https:&#x2F;&#x2F;admiralcloudberg.medium.com&#x2F;russias-potemkin-miracle-the-story-of-ural-airlines-flight-178-5608e797c63e" rel="nofollow">https:&#x2F;&#x2F;admiralcloudberg.medium.com&#x2F;russias-potemkin-miracle...</a>.
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ok_dadover 1 year ago
I can&#x27;t imagine having to hear explosions every 2 minutes for 20 days!<p>The Army is doing some artillery training during the day and night for the past week or so in my area, but luckily they aren&#x27;t doing it every 2 minutes all day and night, just for a few hours up until about 11 or 12 at night and maybe every 5 or 10 minutes they will fire a few rounds. It doesn&#x27;t bother me anymore after hearing it constantly, but I also live directly next to a very busy street, so I am pretty used to loud noises. Maybe next year when they do the training again I&#x27;ll try to pinpoint the explosions using this method (just for fun, because I am pretty sure there&#x27;s only one firing range around here).
VMGover 1 year ago
My neighborhood had a similar issue a while ago (suspected fireworks). I imagined a mobile phone app solution based with high precision timing from GPS signal. Maybe there is a market for it...
PaulHouleover 1 year ago
I cannot understand why the Canada Goose is protected under federal law. There are so many in Stewart Park that I think about taking one down with a net or a bolo but (1) I could get in trouble and (2) I find commercial goose meat to be disgusting (when they talk about eating a goose in a Dickens novel I gag) and can&#x27;t imagine a wild goose is palatable at all.<p>(I do have reports though that the eggs are great, I think commercial goose eggs make the best Pirogi, and that someone was able to take two eggs from a nest year after year and even though they hissed bitterly the same pair would come back again year after year.)
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Log_out_over 1 year ago
Artillery triangulation app.<p>Imagine using such a farmers setup as vortex cannon, you could down non turbulence resistant air vehicles such as drones and glide bombs, with good timing.
sandworm101over 1 year ago
&gt;&gt;&gt; Farmers with field crops are often beset with Canadian Geese overwintering in the Willamette Valley.<p>No. I strongly suspect they are dealing with Canada Geese. They are dominant in the photos. <i>Canadian</i> geese would be some random species of geese carrying a Canadian passport. <i>Canada</i> geese are the distinct grey-black species aka cobra chickens.<p><a href="https:&#x2F;&#x2F;midwesternnewspapers.com&#x2F;dont-cross-the-dreaded-canadian-cobra-chicken&#x2F;" rel="nofollow">https:&#x2F;&#x2F;midwesternnewspapers.com&#x2F;dont-cross-the-dreaded-cana...</a>
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xnxover 1 year ago
Nice work. I feel like there must be some way to triangulate the sound source through direct calculation, but that trigonometry is too advanced for me.
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andrewlaover 1 year ago
More than the code, I&#x27;d be very interested in having the dataset be made public.
mmh0000over 1 year ago
I really dislike Python.<p>This is a clean install of Python straight from the Python developers in a clean container. And it doesn&#x27;t work. I figured I must need &quot;points&quot; so I pip-installed that.<p>Feels like every time I try to use Python, stupid, incomprehensible errors such as this occur:<p>```<p><pre><code> root@1623eb794014:&#x2F;# .&#x2F;tri.py Traceback (most recent call last): File &quot;&#x2F;&#x2F;.&#x2F;tri.py&quot;, line 6, in &lt;module&gt; from points import Point, Block ImportError: cannot import name &#x27;Point&#x27; from &#x27;points&#x27; (&#x2F;usr&#x2F;local&#x2F;lib&#x2F;python3.12&#x2F;site-packages&#x2F;points&#x2F;__init__.py) </code></pre> ```
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