Lithuanian startup launches open-source network to detect Shahed-type drones
34 points by giuliomagnifico 3 hours ago | 16 comments

dmos62 10 minutes ago
That's cute, but Ukrainians have been deploying an acoustic detection system at scale for years and it's literally battle tested and proven to scale. Volunteering is great, but this seems pointless. If we're serious about defence, cooperation with Ukies and expansion of the EU defence sector is the way. Phones against windows will not deter ww3.
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Hnrobert42 2 minutes ago
Wow. This may be the most offensively condescending messages I've seen on HN.

And unnecessarily so, to boot. Is the Ukrainian system open source? Can you link to it?

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tristanj 2 hours ago
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.

The latest versions of Shahed can reach 5000m in altitude, which would largely be inaudible on the ground.

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warumdarum 31 minutes ago
So film the sky during charging and run a llm on it?
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anovikov 39 minutes ago
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.
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AIcanbiteme 10 minutes ago
Baltics are very involved in the war in Ukraine, for instance, Slovenia started NAFO.
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MiracleRabbit 18 minutes ago
There are extremely sensitive differential pressure sensors available from Sensirion that aren't overly expensive.

If these Shahed drones have a propeller they should have a brutal signature between 0-250Hz as they are moving a lot of air.

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.

That 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).

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.

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stavros 7 minutes ago
Isn't detecting pressure waves in air exactly what microphones do?
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MiracleRabbit 5 minutes ago
Yes. But they usually are not performing very good between 1-250Hz.

Sensirion is using a thermal flow-sensing principle method which is basically a heated plate that cools/heats up when air passes it - making it extremely sensitive.

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tpolm 2 hours ago
I wonder how this system can be protected from spam - if anyone can send data there, enemy can, too
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embedding-shape 2 hours ago
I feel like if/once they reach the number of expected participants (10k), it'd be easy to filter out the spam as long as the majority are truthful.
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sourcegrift 32 minutes ago
Remind me again what the meaning of spam is
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reboot81 49 minutes ago
Wouldn’t a purpose built Esp32 with microphones aimed at the sky do a better job? It would be always on, better directional targeting.
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rdtsc 39 minutes ago
I believe Ukrainians had already deployed such a system. This is specifically designed to use old Android phones already sitting in a drawer somewhere without any other use, and most importantly by anyone without technical skills.
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tristanj 2 hours ago
SpaceX received a $4 billion military contract to do this, but with radar and from orbit.
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Avicebron 27 minutes ago
As much as I like to point and guffaw at "bad evil rocket man" the from orbit bit is doing a massive amount of lift (pun not intended) for that price.
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paganel 2 hours ago
[flagged]
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