4 ms·

What are the supposed dangers? I can think of turning drones into self-guided missiles, obviously intercepting from the front since they are slow, but you can

by 323 4y ago

What are the supposed dangers? I can think of turning drones into self-guided missiles, obviously intercepting from the front since they are slow, but you can track planes visually too. And if this is to prevent foreign states, I'm sure in a couple years you'll be able to buy this stuff on AliExpress.

hutzlibu 4y ago
https://m.alibaba.com/product/1600484445946/Silent-Sentry-Passive-Radar.html https://m.alibaba.com/product/1600484445946/Silent-Sentry-Pa...
- deleted 4y ago
  [deleted]
ethbr0 4y ago
The dangers are the capability to intercept stealth cruise missiles. Which appear to be the future weapon du jour for degrading integrated AA systems from outside A2/AD bubbles.
- myrryr 4y ago
  The other danger is, by removing the ability for people to experiment and understand the tech, we will lose out to places which can. They will have the engineers, and we will have effectively stopped ours from becoming so.
  - nradov 4y ago
    Defense contractors continue to devote huge resources to experimenting with and understanding all forms of radar technology. You just don't read about it on HN.
toss1 4y ago
Not just supposed dangers — real danger. The saying the mil guys have about using active radar is "he who lights up first gets smoked". As in you turn on your radar, and it'll be a beacon seen in milliseconds, located in a few more milliseconds, and then receiving an incoming missile. Radar has to be passive, using ambient RF frequency 'noise', in any modern military operating theater to survive. So, yes, keeping passive radar technology as maximally secret as possible among the world's democracies retains an advantage over the expansionist autocracies, which are increasingly belligerent, from Russia attacking in Europe, China making louder noises about attacking Taiwan (sending fighter jets to the shore today), NK launching missiles near Japan... yeah, we need to keep an edge.
- Natsu 4y ago
  Why not just separate the emitters and receivers a bit more, then? Wouldn't it work to put some cheap drones or other hardware that "light up" and send nice pulses out for you to get info from that are far enough away from your real position, or am I missing something? If they're cheap enough, it wouldn't be very worthwhile to destroy them I'd think. I mean it'd probably be in your interest to let them waste million dollar missiles on hundred dollar drones if you could get them to do so. Or does something like this exist that I'm just unaware of?
  - nraynaud 4y ago
    My understanding is that GSM towers are very predictable and well located emitters.
  - guhidalg 4y ago
    Isn’t this what AWACS and datalinks are for?
  - toss1 4y ago
    It isn't my area, but I think you're on the right track. Most radar systems have already (for decades, AFAIK) separated the emitter from the control panel with at least a long cable, so when the emitter gets smoked, at least the operators are more likely to survive. The USAF & DARPA are already publicly working on aerially deployed drone swarms, and it would not surprise me in the slightest if a swarm of theater emitters was among the goals (but I've got no inside info to share).
  - bradknowles 4y ago
    You're getting dangerously close to an idea I had back in 1991, when I was working at the Defense Information Systems Agency, in the basement of the Pentagon. I talked to our security officer, and he put me in touch with a guy from the intelligence side of the house. I explained my idea, he said they already had something in that space, and that I shouldn't say anything more about it to anyone. I never heard anything further on that subject. To this day, it is one of two things I don't talk about.
RachelF 4y ago
The dangers are to modern stealth aircraft like the F-35. They optimize the stealth to work in the ~5-20GHz range. They are easy to pick up in the UHF and lower band, although at these lower frequencies much accuracy is lost. This is how NATO lost an F-119 in Yugoslavia. The old Russian system used ~0.9GHz frequencies and a very large explosive warhead. That combined with operator skill and NATO being overconfident resulted in a loss of the aircraft, although not the pilot.
gnramires 4y ago
Disclaimer: not a weapons specialist. I'm not sure passive radar has much use as missiles and such. But it should be quite useful defensively (radar is useful for detecting fast moving incoming objects), so I don't think it's very justified to put it under arms control. Drones for instance can be guided with off-the-shelf technology against slow moving targets. I'm definitely not absolutely against arms control, the extreme case of course is nuclear proliferation. I think it's best to keep nuclear secrecy and try to break nuclear proliferation and even disarm countries as much as possible. It's just too dangerous, hopefully an unnecessary risk and unnecessary technology for a peaceful world.

by 323 4y ago

hutzlibu 4y ago

https://m.alibaba.com/product/1600484445946/Silent-Sentry-Passive-Radar.html https://m.alibaba.com/product/1600484445946/Silent-Sentry-Pa...

deleted 4y ago
[deleted]

ethbr0 4y ago

The dangers are the capability to intercept stealth cruise missiles. Which appear to be the future weapon du jour for degrading integrated AA systems from outside A2/AD bubbles.

myrryr 4y ago
The other danger is, by removing the ability for people to experiment and understand the tech, we will lose out to places which can. They will have the engineers, and we will have effectively stopped ours from becoming so.
- nradov 4y ago
  Defense contractors continue to devote huge resources to experimenting with and understanding all forms of radar technology. You just don't read about it on HN.

toss1 4y ago

Not just supposed dangers — real danger. The saying the mil guys have about using active radar is "he who lights up first gets smoked". As in you turn on your radar, and it'll be a beacon seen in milliseconds, located in a few more milliseconds, and then receiving an incoming missile. Radar has to be passive, using ambient RF frequency 'noise', in any modern military operating theater to survive. So, yes, keeping passive radar technology as maximally secret as possible among the world's democracies retains an advantage over the expansionist autocracies, which are increasingly belligerent, from Russia attacking in Europe, China making louder noises about attacking Taiwan (sending fighter jets to the shore today), NK launching missiles near Japan... yeah, we need to keep an edge.

Natsu 4y ago
Why not just separate the emitters and receivers a bit more, then? Wouldn't it work to put some cheap drones or other hardware that "light up" and send nice pulses out for you to get info from that are far enough away from your real position, or am I missing something? If they're cheap enough, it wouldn't be very worthwhile to destroy them I'd think. I mean it'd probably be in your interest to let them waste million dollar missiles on hundred dollar drones if you could get them to do so. Or does something like this exist that I'm just unaware of?
- nraynaud 4y ago
  My understanding is that GSM towers are very predictable and well located emitters.
- guhidalg 4y ago
  Isn’t this what AWACS and datalinks are for?
- toss1 4y ago
  It isn't my area, but I think you're on the right track. Most radar systems have already (for decades, AFAIK) separated the emitter from the control panel with at least a long cable, so when the emitter gets smoked, at least the operators are more likely to survive. The USAF & DARPA are already publicly working on aerially deployed drone swarms, and it would not surprise me in the slightest if a swarm of theater emitters was among the goals (but I've got no inside info to share).
- bradknowles 4y ago
  You're getting dangerously close to an idea I had back in 1991, when I was working at the Defense Information Systems Agency, in the basement of the Pentagon. I talked to our security officer, and he put me in touch with a guy from the intelligence side of the house. I explained my idea, he said they already had something in that space, and that I shouldn't say anything more about it to anyone. I never heard anything further on that subject. To this day, it is one of two things I don't talk about.

RachelF 4y ago

The dangers are to modern stealth aircraft like the F-35. They optimize the stealth to work in the ~5-20GHz range. They are easy to pick up in the UHF and lower band, although at these lower frequencies much accuracy is lost. This is how NATO lost an F-119 in Yugoslavia. The old Russian system used ~0.9GHz frequencies and a very large explosive warhead. That combined with operator skill and NATO being overconfident resulted in a loss of the aircraft, although not the pilot.

gnramires 4y ago

Disclaimer: not a weapons specialist. I'm not sure passive radar has much use as missiles and such. But it should be quite useful defensively (radar is useful for detecting fast moving incoming objects), so I don't think it's very justified to put it under arms control. Drones for instance can be guided with off-the-shelf technology against slow moving targets. I'm definitely not absolutely against arms control, the extreme case of course is nuclear proliferation. I think it's best to keep nuclear secrecy and try to break nuclear proliferation and even disarm countries as much as possible. It's just too dangerous, hopefully an unnecessary risk and unnecessary technology for a peaceful world.