Shahed drones have increased in altitude from ~500m at the beginning of the Ukraine war to 2000-3000m, which is a 4x reduction in noise on the ground. The higher the drones are, the less noise they make at ground level, and the less effective this ground-based microphone system will be. The drones have moved to elevations to make them more difficult to target with ground based weapons. Reductions in ground noise are a secondary effect.<p>The latest versions of Shahed can reach 5000m in altitude, which would largely be inaudible on the ground.
It's not about "can reach", it's fairly easy to get them to fly even higher. It's about danger of interceptors vs danger of detection. Today's Ukrainian detection network (based on radars) is so dense there is no way to hide from it anywhere, anyway, so high altitude wins.
So film the sky during charging and run a llm on it?
There are extremely sensitive differential pressure sensors available from Sensirion that aren't overly expensive.<p>If these Shahed drones have a propeller they should have a brutal signature between 0-250Hz as they are moving a lot of air.<p>Use one differential side and connect it to a kitchen funnel for directional listening the other one to a plastic bottle with a very very small hole in it. It will pick up everything high frequency that's different to the environmental pressure.<p>This way I was able to detect washing machines that had a physical link to house walls for many hundred meters (machine spinning -> house wall shaking -> pressure waves) away.<p>Add this with some GPS PPS frame timestamping and you should have a nice tracking network that doesn't require a lot of bandwidth. But maybe the setup must switch to analog differential pressure sensors as these Senirion-I2C sensors do not have a Sync ping for super precise timestamping.
> Use one differential side and connect it to a kitchen funnel for directional listening the other one to a plastic bottle with a very very small hole in it. It will pick up everything high frequency that's different to the environmental pressure.<p>Nevermind drones, and war, that's all fine; but I <i>need</i> to know more about this. Is there a phrase or name for this I could use to find more information, maybe example schematics?
Interesting! I will like to see your circuits, if any.
Interesting! There are a lot of super loud cars in my urban area. I want to catalog where and when they drive, so I can stand on the side of the street and shake my cane at them.
Isn't detecting pressure waves in air exactly what microphones do?
I wonder how this system can be protected from spam - if anyone can send data there, enemy can, too
SpaceX received a $4 billion military contract to do this, but with radar and from orbit.
Wouldn’t a purpose built Esp32 with microphones aimed at the sky do a better job? It would be always on, better directional targeting.
Baltics are very involved in the war in Ukraine, for instance, Slovenia started NAFO.
[flagged]
[flagged]
Wow. This may be the most offensively condescending messages I've seen on HN.<p>And unnecessarily so, to boot. Is the Ukrainian system open source? Can you link to it?
That statement made ignores several facts.<p>For instance:<p>a) Lithuania is not at war right now. Ukraine is. So the comparison already does not work.<p>b) There are drones entering the airspace of Lithuania somewhat regularly; two weeks ago was the last one: <a href="https://tvpworld.com/93695919/nato-rafale-jet-shoots-down-drone-violating-latvias-airspace" rel="nofollow">https://tvpworld.com/93695919/nato-rafale-jet-shoots-down-dr...</a><p>So, knowing this, but also for more reasons, it absolutely makes sense for Lithuania to not neglect its capabilities, and that includes start-ups that want to be supportive here.<p>> If we're serious about defence, cooperation with Ukies and expansion of the EU defence sector is the way.<p>So at which point has the war been about other countries? Lithuania is not at war and it makes no sense to assume that every other country but Ukraine is clueless.<p>> Phones against windows will not deter ww3.<p>Aha. So pray tell and explain what your plan is against nukes.