101–110 of 249 posts
> It sounds like they had to reverse-engineer the MIPI protocol used on the Pi 5 to do this (since it goes through the RP1 chip), and the way it's architected, you can daisy-chain multiple QuadRF modules together, letting each module calculate it's own phase shift. How are they planning on distributing a shared, highly precise clock for that purpose? That's already a PITA if you do QO-100 modes that need high precisi…
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It detects drones which send out RF signals at the same frequency band. Most drones used in Ukraine are tethered with thin optical wire exactly because one of the first anti-drone measures was to simply jam them at the frequencies the operators used. There are some more advanced anti-drone measures at work: Like blasting them with directed high-energy microwaves to destroy the circuits.
Most drones aren't optical because optical drones sacrifice payload and distance, they're only used when broad spectrum jamming is expected. Jamming of that type is expensive and heavy enough that infantry probably won't be jamming, or light vehicles, or a lot of infrastructure.
One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from. This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)
The army has one of these for sniper triangulation, and Boeing made a civilian version for optimizing sound dampening on the 787. I don’t know if they kept doing that on subsequent planes but I would expect so given how enthusiastic they were about being able to apply the weight budget to greater effect. You need really high clock rate sensing to differentiate the arrival time for sound from microphone arrays where t…
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> that sees the transmitter on the drone. The comm link is the obvious weak spot on the drone Isn't most drones run by fiber optic nowadays around the front-lines though? Can't really jam those, but maybe still detect it somehow?
According to CivDiv's channel about 70% of the drones used are still RC FPV drones. They are cheaper longer range and have a slightly simpler supply chain. Fiber optic cable prices have exploded because of the war.
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Fluke has made an acoustic imager for a while now. It is used for detecting leaks: https://www.fluke.com/en-us/product/industrial-imaging/fluke...
There are a few knockoff options too, which are not quite as nicely calibrated, but get the job done for much less than Fluke-level prices. Like the FOTRIC TD2. I think a few people have made homebrew versions too, like this one mentioned on HN: https://news.ycombinator.com/item?id=45137584
fluke $25k
flir $10k
td2 $1k
These are the kinds of things you look at and think - maybe I DO need night-vision, or a soldering iron with a cpu, or a thermal imager, or a steerable endoscope or now an acoustic imager....
One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from. This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)
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Frequency hopping is not THAT difficult.
Brute force wide band jamming would be easy too and would make hopping ineffective. Unless drones use self tuning antennas to overcome losses, they can't hop too far away from the antenna resonance frequency, which makes jammers job easier.
I just kinda skimmed through it, so it detects drones in sky? Am I understanding this correctly? That might have some defense application considering what's going on in Eastern Europe right now.
> That might have some defense application considering what's going on in Eastern Europe right now. This is a bog-standard phased-array RDF calibrated for WiFi freqs; that stuff is already in every single defense show. Also, that's why there's jamming everywhere (to blind that kind of things) and why many UAVs are now tethered to optical fibers instead of being RF-controlled.
> It sounds like they had to reverse-engineer the MIPI protocol used on the Pi 5 to do this (since it goes through the RP1 chip), and the way it's architected, you can daisy-chain multiple QuadRF modules together, letting each module calculate it's own phase shift. How are they planning on distributing a shared, highly precise clock for that purpose? That's already a PITA if you do QO-100 modes that need high precisi…
check out https://QuadRF.com/docs/
One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from. This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)
The army has one of these for sniper triangulation, and Boeing made a civilian version for optimizing sound dampening on the 787. I don’t know if they kept doing that on subsequent planes but I would expect so given how enthusiastic they were about being able to apply the weight budget to greater effect. You need really high clock rate sensing to differentiate the arrival time for sound from microphone arrays where t…