| ▲ | Lithuanian startup launches open-source network to detect Shahed-type drones(lrt.lt) |
| 50 points by giuliomagnifico 3 hours ago | 25 comments |
| |
|
| ▲ | tristanj 2 hours ago | parent | next [-] |
| 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. |
| |
| ▲ | anovikov an hour ago | parent | next [-] | | 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. | |
| ▲ | warumdarum an hour ago | parent | prev [-] | | So film the sky during charging and run a llm on it? | | |
| ▲ | Neywiny 11 minutes ago | parent [-] | | Or an image detection model. Fraction of the compute and can run even on edge embedded. And easy to train with your own data |
|
|
|
| ▲ | MiracleRabbit an hour ago | parent | prev | next [-] |
| There are extremely sensitive differential pressure sensors (like SDP600-25Pa) 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. 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. 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. |
| |
| ▲ | customguy 17 minutes ago | parent | next [-] | | > 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. Nevermind drones, and war, that's all fine; but I need to know more about this. Is there a phrase or name for this I could use to find more information, maybe example schematics? | | |
| ▲ | MiracleRabbit 5 minutes ago | parent [-] | | The Sensirion SDP600-25Pa speaks I2C and only has a handful of primitive commands. Add this and 3.3V and you are done. I'm 99.5% sure if you throw Claude with a datasheet on it will Slop out working code for a ESP32 with ESP-IDF. |
| |
| ▲ | Hnrobert42 32 minutes ago | parent | prev | next [-] | | 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. | |
| ▲ | ejanus 18 minutes ago | parent | prev | next [-] | | Interesting! I will like to see your circuits, if any. | | |
| ▲ | MiracleRabbit 7 minutes ago | parent [-] | | Not much circuits needed. The SDP600-25Pa speaks I2C and only has a handful of commands. Just read it out with a microcontroller you love (like ESP32) and send the samples to a host for analysis. To not overwhelm the poor processor and Wifi maybe better a bunch of frames (like 512 or more). |
| |
| ▲ | stavros an hour ago | parent | prev [-] | | Isn't detecting pressure waves in air exactly what microphones do? | | |
| ▲ | MiracleRabbit 43 minutes ago | parent [-] | | 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 in this range. |
|
|
|
| ▲ | tpolm 2 hours ago | parent | prev | next [-] |
| I wonder how this system can be protected from spam - if anyone can send data there, enemy can, too |
| |
| ▲ | embedding-shape 2 hours ago | parent [-] | | 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. | | |
|
|
| ▲ | tristanj 2 hours ago | parent | prev | next [-] |
| SpaceX received a $4 billion military contract to do this, but with radar and from orbit. |
| |
| ▲ | Avicebron an hour ago | parent [-] | | 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. | | |
|
|
| ▲ | reboot81 an hour ago | parent | prev | next [-] |
| Wouldn’t a purpose built Esp32 with microphones aimed at the sky do a better job? It would be always on, better directional targeting. |
| |
| ▲ | rdtsc an hour ago | parent [-] | | 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. |
|
|
| ▲ | AIcanbiteme an hour ago | parent | prev [-] |
| Baltics are very involved in the war in Ukraine, for instance, Slovenia started NAFO. |
| |
