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Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves
by supernova87a 1y ago
Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves coming off the poles from the rotors -- it seems to me the whole field of non-invasive sensing (and using existing/ambient emission sources) is getting pretty impressive.
- nashashmi 1y agoWhat kind of helicopter of what size are we talking about here that can actually get close to a utility pole with wires going across?
- trhway 1y agoI think you can do it from a distance, just need to have directed microphone (or use laser “microphone”)
- shitpostbot 1y agoThat makes sense. It's probably less "doing crazy convolution calculations on how sampled ambient noise changes as the helicopter gets close to a pole", and more "rotten wood vibrates slower"
- gregoryl 1y agoFYI, you've been hellbanned for seemingly 6 years. Probably the account name triggering a spam filter? Email hn@ycombinator.com, they may be willing to unban you, so other people can see your posts.
- gerdesj 1y agoI live near a helicopter factory and when the spinning towers are in use, you hear all sorts of auditory patterns as you move around the town. When they are test flying - similar and the Police have one and there is an air ambulance too. My Dad's other staff car in the '80s was a Gazelle and in the '70s he whizzed around in a Sioux. I've seen and heard a lot of helos! I have absolutely no doubt that with some funky signal processing you can do all sorts of things.
- morkalork 1y agoAnd here I thought living behind a few garages that rev engines all day long was disturbing
- gerdesj 1y agoIts much less disturbing than living under a flight path to an airport. I actually like the sound of a helo - its variable and interesting, as is a piston powered fixed wing aircraft. Mind you I also lived near RAF, USAAF and Luftwaffe bases back in the day and several flights of Phantoms, Starfighters, Jaguars and Tornadoes and the rest can make quite a din. Phantoms were pretty huge engined beasts with minimal effort made for noise reduction. A "finger four" lighting up their after burners to gain altitude really fast is ear splitting.
- trenchpilgrim 1y agoLook up "Helicopter tree trimming" and prepare to be amazed.
- fsckboy 1y agoalso look up "helicopter high voltage wire"
- privatelypublic 1y agoHV transmission line inspection routinely has the linesmen crawl out of helicopters onto the lines and back. Granted, as far as I know its the highest skill and most difficult helicopter job.
- jacquesm 1y agoI've seen that in person while in Canada and it is most impressive. The moment they discharge the differential between the helicopter and the line is just awesome. The firebreak clearing operations are also something to behold. From a very safe distance.
- bri3d 1y agoSource article (2001!): https://electricenergyonline.com/energy/magazine/4/article/new-technology-uses-airborne-lasers-and-artificial-intelligence-to-assess-wood-structure-reliability.htm https://electricenergyonline.com/energy/magazine/4/article/n... I can’t tell if this ever became a reality; I know of more modern approaches attempting to use thermal and multi spectral imaging to achieve the same goal.
- aaron695 1y ago[dead]
- odyssey7 1y agoAnd yet CT scans that dose patients with radiation are still standard of care.
- nightfly 1y agoYou get a lot more detailed information out of a CT scan
- odyssey7 1y agoNot more detailed than an MRI. And the longer we push CT scans, the longer we delay the advancement of less invasive technologies.
- deleted 1y ago[deleted]
- _kb 1y agoI don’t think having them stand under low flying aircraft is much safer.
- odyssey7 1y agoA typical CT scan delivers enough radiation to give a healthy person a 1/500 chance of getting a cancer in their lifetime that they otherwise would not have gotten. The risk is higher for children. We have people working around low-flying aircraft all the time. I’m guessing the associated job risks are better. When you take those jobs, it’s because you want to make money, not because your life is at risk, there’s information asymmetry between you and the medical provider who is indirectly rewarded for billing for scans, and the overarching medical system prioritized CT scans over MRIs while our engineering culture failed to establish something safer and cheaper. Would you play Russian Roulette with a revolver with 500 chambers and 1 bullet? What if by doing so a hospital would receive thousands of dollars, and would go on to be paid many more thousands of dollars if you got unlucky? The cost-benefit trade-off is there, and the powers that be are prioritizing cancer.
- bcrl 1y agoIn telecommunications construction we are taught to make ample use of the "hammer test" when working on and around poles. The difference in sound between a good pole, a marginal pole and a completely rotten pole is quite significant.
- jacquesm 1y agoYou could of course just bury your lines.
- bcrl 1y agoToo expensive where I live. Rocks, hills and trees: the natural enemies of buried fibre and wireless networks. One of my competitors took 6 months to bury a cable in granite that would've been a 5 day aerial job.
- WorldMaker 1y agoAlso where I live (a karst region) other expensive things we deal with are frost lines (frost heave is a real issue; water expands as it freezes, things in the ground don't stay in the ground if ice is expanding into their space) and limestone rock underfoot (sinkholes are a real issue; dig wrong or too deep or not carefully enough and cave in the ground right under you, or worse, someone's house right next to you). Google Fiber wrecked entire city streets relearning these things the dumbest way possible (then left the street repair bills to the us the taxpayers, because of course they did).
- deleted 1y ago[deleted]
- skullone 1y agoI'm so glad you say that. Resi aerial is perfect in most locations. No dig, no service boxes in front yards, under someone's unpermitted driveway pour, ample power easily, a guy in a bucket truck is all you need. Trenchless works well when it can, but even reasonable infrastructure underground is twice as expensive. I love seeing a neighborhood lit up in fiber in 2-5 days and subscribers online at 1-10Gb in soooo many places. Keeps crews busy either way :D
- Xmd5a 1y agoA lot of value in machine learning is in establishing measures by proxy.
- motorest 1y ago> Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves coming off the poles from the rotors There is a whole field dedicated to this, called non-destructive testing. Modal response (i.e., monitor how a structure vibrates in response to an excitation) is a basic technique that features in multiple areas such as structural health monitoring and service life estimations. Some mechanics also do this by placing the tip of a screwdriver against a point in an engine and place their ear against the screwdriver's handle. If it's not sounding right, the engine has problems. Even pottery. You should hear the sound of a pot after you tap it. If it's muffled then odds are it has internal cracks.