31–40 of 104 posts
Earlier quoted context omitted.
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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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…
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.
What's with that "vs" trade-off?
You're saying avoiding detection requires high altitudes.
What do interceptors have to do with that?
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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?
I don't know about condescension, but a degree of grounding is in order, I believe. European sense of defence is waking up, but it still needs a lot of stimulation, and patting ourselves on the back for some volunteer work is not that.
If these Shahed drones have a propeller they should have a brutal signature between 0-250Hz as they are moving a lot of air. And if the engine speed of the Shahed stays constant it will be even easier to detect it ("Angry lawnmower sound".. but that's only the high frequency part of it). There are extremely sensitive differential pressure sensors (like SDP600-25Pa) available from Sensirion that aren't overly expensiv…
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That statement made ignores several facts. For instance: a) Lithuania is not at war right now. Ukraine is. So the comparison already does not work. b) There are drones entering the airspace of Lithuania somewhat regularly; two weeks ago was the last one: https://tvpworld.com/93695919/nato-rafale-jet-shoots-down-dr... So, knowing this, but also for more reasons, it absolutely makes sense for Lithuania to not neglect i…
If these Shahed drones have a propeller they should have a brutal signature between 0-250Hz as they are moving a lot of air. And if the engine speed of the Shahed stays constant it will be even easier to detect it ("Angry lawnmower sound".. but that's only the high frequency part of it). There are extremely sensitive differential pressure sensors (like SDP600-25Pa) available from Sensirion that aren't overly expensiv…
If these Shahed drones have a propeller they should have a brutal signature between 0-250Hz as they are moving a lot of air. And if the engine speed of the Shahed stays constant it will be even easier to detect it ("Angry lawnmower sound".. but that's only the high frequency part of it). There are extremely sensitive differential pressure sensors (like SDP600-25Pa) available from Sensirion that aren't overly expensiv…
Doesn't wind fool this?
Only pressure waves coming into all holes at the same time will reach sensor.
Never tested it. Only a Gedankenexperiment as Einstein would say.
Earlier quoted context omitted.
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.
> It's about danger of interceptors vs danger of detection. What's with that "vs" trade-off? You're saying avoiding detection requires high altitudes. What do interceptors have to do with that?
Detection is facilitated by radar, low altitude means flying under the radar (due to curvature of the Earth) - except radar network is now so dense, it in practice can't work anymore. So they can fly low or high they will be detected anyway - but flying high reduces interceptor's reach and makes intercept geometry harder, giving them better chances to slip through.