Meet Drone Shield, an Ambitious Idea For a $70 Drone Detection System 159
An anonymous reader writes "Here's an Interesting idea of how to use a Raspberry Pi and a few other inexpensive items to make a low cost detection system. From the article: 'The Drone Shield would combine a Raspberry Pi, a signal processor, a microphone, and analysis software to scan for specific audio signatures and compare them against what known drones sound like. (Because obviously a Predator drone is going to sound very different than a small quadcopter.) Once a match is found, the Drone Shield then sends an e-mail or SMS to its owner...'"
Interesting... (Score:2)
Good job. This tech could be used for a lot of other good things as well. Basically an electronic ear for specific frequencies. I'm surprised it's not much more developed.
Question is, will it have better acuity then a trained dog with excellent hearing?
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Ofcourse it's been done. There's a lot of military equipment that works like this.
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I figured sonar and the like was high powered and non-passive. But after seeing the link below from anonymous in another thread of the discussion I see the idea of passive acoustic sensing has been around long enough (pre WWII) to be highly developed.
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Yes, I did not think very deeply about it. I should have known better.
Re:Interesting... (Score:5, Funny)
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Even if you can filter out the noise from the drone your drone shield's sitting on - how exactly does a drone shield sound?
mobile drone shield (Score:2)
because naturally you need a defensive swarm of drone that move with you through the world, forming a dome around you, to shield you from the potentially bad drones that are coming to get you, or perhaps happen to be a part of the drone shield of the guy standing next to you.
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If "better acuity" is a euphemism for it won't shit on your lawn, then yes.
Re:Interesting... (Score:5, Insightful)
It is much more developed, you just don't realize it. This sort of signal processing is used in ultrasound machines, your car, my boat, fetal heartbeat monitors, little credit card readers that attach to your phone via headphone jacks. ALL SORTS OF STUFF.
Its all just an application of some FFTs and some weighting. It isn't even non-trivial for anyone with some basic understandings.
Without any prior knowledge, I went from no understanding to of FFTs to writing code to detect lean fuel during runtime on my R/C airplane. A Raspberry PI is also way more CPU power than needed to do it, which means it can also do a whole bunch of other stuff too.
Re:Interesting... (Score:5, Funny)
A Raspberry PI is also way more CPU power than needed to do it, which means it can also do a whole bunch of other stuff too.
My ++ model will mine Bitcoins between drone attacks!
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While being used to run a 3D printer, of course.
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Imagine a Beowulf cluster of these!
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Without any prior knowledge, I went from no understanding to of FFTs to writing code to detect lean fuel during runtime on my R/C airplane.
That is fascinating. I feel motivated to go out and try myself, now
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The ars article is light on details, but it looks like the author is leaning towards training a neural net to do the pattern matching since he mentions http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA320924 [dtic.mil]
I probably wouldn't go the FFT route since a neural net or wavelets probably work better...but I also haven't done anything of the sort in the past 5-10 years, so maybe things got better. You're looking at the audio signature to determine lean fuel?
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Spend a bit more and go the simpler route of radio detection finding equipment. Drones are really quite radio chatty and sourcing a radio emission from altitude (video feed so the remote operator can see where they are going) tend to give them away.
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little credit card readers that attach to your phone via headphone jacks.
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FFTs are not used in magstrip reading software.
But they are used extensively while processing audio signals to digital ones.
little credit card readers that attach to your phone via headphone jacks.
The OP specified something that plugs into the analog microphone jack of a phone to transfer digital information from a credit card, so I would say a DFT is probably occurring somewhere in there. :)
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Trained dog? Probably not. I guess it's possible, but probably not. But - you can put this piece of pie on a pole, or whatever, and forget about it. Toss it on your roof, or put it on your bird feeder, whatever. No need to walk it, water it, or much anything else. No fleas. It won't steal your covers in the middle of the night. No muddy tracks in the hallway. All that it will ever need is a supply of electrons!
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Hehe, in some countries dogs are the low tech cheap option when theres tons of strays already. You'd be surprised at how easy some are to train, I would imagine some train themselves. We have a dog, and there are certain things that set her running and barking and its not the neighbors, its something halfway across the neighborhood. No way for us humans to tell what it was.
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I think its more down the line of : You just fixed your patio cover. Did you have a permit to do that (fee)? Did you have it inspected by the city inspector ( another fee ). We need to re-do your property tax!
And gee whiz, what if someone is hanging their wash in the back yard on a clothes line instead of using a dryer!
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And gee whiz, what if someone is hanging their wash in the back yard on a clothes line instead of using a dryer!
WHAT?? Someone drying clothes without using lots of electrical energy to power a big machine? How Un-American! :-)
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You're worried that drones would allow them perfect enforcement of laws? How is this a bad thing exactly?
Because the laws are not perfect....far, far from perfect.
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No.
What I think most people are worried about are false-positives. I don't want my front door destroyed, my friendly dog shot to death, and my reputation smeared because some doofus with a drone mistakenly ended up identifying the infrared signature of my heated fish tank as a "growing operation" inside the house, for example.
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How about all the stupid, pointless, and even unconstitutional laws?
Hot Springs, Arkansas decided that it was going to "beautify" the lake fronts around it. So, they took to the skies, and took photos of everything. Your old care sitting out back had to be towed away. Your aluminum can collection had to go. The weathered siding on some buildings had to be replace, while other buildings were condemned. All because they wanted a "pretty" tourist trap.
And, most of it was wrong.
This was years ago, before t
Wakey, wakey, Pollyanna... (Score:2)
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As a commercial sUAS operator, this is depressing. To think that Americans believe their lives are so interesting that the government would care to spy on them is downright unbelievable
For that, the gouvernment put quite a bit of effort into defining what can and what can't be done to American citizens using drones...
And mostly while circumventing the checks and balances.
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I think the person trying to sell these "Drone Shields" should be tried before the Supreme Court
Why? He's done nothing illegal, and certainly nothing as immoral as selling or running tech that can only profitably be used for warfare and surveillance.
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Its projects like these that lead to things like.... uh... radar etc... he should get a government grant.
Range (Score:5, Insightful)
A Predator has an operating ceiling of 25,000 feet. You think a raspberry pi and mic is going to hear a Predator drone in cruise mode that's 5 miles above? You can't even hear a massive passenger jet at that altitude! Now a quadcopter is a different story, as they are as loud as can be, but saying this system would work on something like a Predator is a stretch.
Re:Range (Score:5, Interesting)
Yeah, you'll need some bigger tools [greg.org] for that.
Bigger tools -- was Re:Range (Score:2)
"Yeah, you'll need some bigger tools for that."
Can't we just raise money to buy/rent/bribe the "bigger tools" who keep telling us that this (drone-use) horse$hit is "legal?" Just sayin'...
Re:Bigger tools -- was Re:Range (Score:5, Interesting)
I don't think that I disagree with your ideals. Having said that, and - really, I don't disagree with them in all likelihood, I must ask, "In which way(s) are you asserting that drones, or their use(s), illegal to start with? What, specifically, is illegal about drones? What laws are being broken with them?"
I ask because, well, I fear that they will become so inexpensive to operate (including training) that they will be used to increase surveillance which, while against my ideals, probably doesn't (in and of itself) violate any laws. I'd like to be able to make a clear, factual, and reasonable argument against the increased use of drones but I don't have any arguments to make against it that are logical and truthful. I can only state that I'm afraid of what it may turn into.
Even in my worst imagined fears concerning these drones, I'm unable to find any laws that are being broken. Perhaps you come from a different country than I do? I'm from the United States of America. We're not all that free here which means that there are a lot of laws. Given the number of laws it is impossible for me (I'm not a lawyer, even then it would still be impossible) to know all of the laws. However, I'm reasonably aware of the many laws that we have to protect us and I'm reasonably aware of the laws that the government must follow and I'm unable to point to anything specifically about drones (or their proposed use, or even with the uses that I'm afraid of) which are illegal.
So, I'm not asking you to be my research assistant or the likes. You stated that drone use was illegal which isn't very specific and certainly isn't true so I'm hoping that you have something more concrete and that you can actually point out which laws being broken by these. If you could provide specifics and case law that would be most excellent too but I'm trying to not ask for too much.
See, in my opinion, they are making their surveillance too intrusive and too easily accomplished. In this day and age we're able to be monitored in most everything we do and, while this has always been legal, it has become increasingly easy for this to be done and for this information to be shared. The use of drones by police, municipalities, and private companies to monitor, photograph, and track a person is just yet another step in the age of zero privacy. I'm quite certain that it (that portion specifically) is legal though I'm equally certain that it shouldn't be. I can vocalize, express, this as a worry and all and that may affect the opinions of some but if it is illegal then there's an even greater chance of demonstrating the harm that this can cause to society.
I don't know... Perhaps you meant it should be illegal? I'm really unable to find anything that indicates the use of drones would be illegal in and of itself and that includes FAA regulations and the likes - I've looked. I could be missing something. Then again, this is /. and you could just be an insane zealot who thinks that anything they don't like is illegal but I'm hoping you're more honest and logical than that. Trust me on this, I've seen it here before...
Either way, I'm hoping you have something more concrete than the generic statement that the use of drones is illegal because, well... No, no it isn't illegal in and of itself. If there's some specific manner that they're being used that is illegal then I'm quite interested in knowing what it is. Like I said, I've even met people online who thought that DST (Daylight Savings Time) was illegal so you could just be one of the crazy ones but I'm sort of hoping you're not. It would be, admittedly, amusing but it wouldn't actually be beneficial to me.
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I am not even sure that it can violate that as the courts have pretty much decided that we have no right to privacy outside of our homes or even in our homes - as an example of the loss of privacy in our homes look at the people who have been busted for walking around nude in their home with their blinds open.
Re:Range (Score:4, Insightful)
Re:Range (Score:5, Funny)
So now the highly directional microphone has to be pointed toward the undetected drone in order to detect it? That makes perfect sense.
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Hehe, yeah, but a whole bunch of these all over the place in a distributed network that all dumped to one database could make a very interesting historical map of drone flight paths.
Re:Range (Score:5, Funny)
Sounds like you need a beowulf cluster for that!
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The best location would be in a more empty state with lots of new drone 'schools' for maintenance, new staff needing many flight hours. This would give you some open space, a wide sky to scan and that real sound over many months.
Due to the nature of drone training, one would expect this to be away from suburbia, the big air traffic hubs. Based on video cap
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Aye I was thinking the idea would be for a more opt in approach and people would do either a seti at home type application or it would get sent off to a nerd somewhere with some computing power. Since the gentleman running the project picked the raspberry pi as a platform it already has cellular capability to phone home collected data over time.
Though personally I would be a bit iffy about leaving my rasberry pi out on a mountain range somewhere un-attended. Also the places you mention that would be good sp
Re:Range (Score:5, Interesting)
So now the highly directional microphone has to be pointed toward the undetected drone in order to detect it? That makes perfect sense.
If you're sophisticated and have multiple microphones in a well planned array, then you can aim your microphone in software and sweep the sky looking for the signature. Look up acoustic beam-forming. If the array is large enough you can estimate distance as well as angle. The bonus is that you get actual tracking instead of just detection.
The problem would be processing power though. Simple implementations could range from 4 microphones that you sum/subtract to look at quandrants, up the way to something approaching what the US Navy does with its towed arrays. I doubt the PI could handle the processing of the signals in both the time domain to get tracking, and the frequency domain to do target qualification.
Of course you also have the question of what do you do when you detect one? Aim a camera at it? Fire off your green laser? (no not suggesting you commit a felony).
Re:Range (Score:5, Informative)
Disclaimer, I was a submarine crewman and though I was a qualified sonar watchstander I was not a sonar tech. I have also studied fairly widely in the unclassified literature.
It's certainly simple - in theory. In reality, picking out such a faint noise from the background is Very Difficult Indeed.
Processing power, both for signal analysis (finding the faint signal) and for beamforming is on the beginning of your problems. Let's just hit the high spots:
Etc... etc... The very definition of a non trivial project. You're essentially trying to replicate what the USN does with it's passive sonar systems, with dull and chipped stone knives. (You don't even have a bearskin. You don't even get a bearskin, just the aforementioned knives.)
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The accuracy of your track is only as good as the accuracy of your microphone positioning. (You won't need surveyor grade accuracy, but you will probably need better than the three meter accuracy that WAAS/GPS provides.) You can't beamform if you don't know the relative locations of your microphones. Oh, and did I mention that sound is refracted as the temperature of the air changes? You'll have to account for that too - assuming you can get accurate enough data on current conditions.
I like solving problems and this is somewhat similar to what I do for a living, so I'll speculate...
In a similar approach to the use of a guide star [wikipedia.org] in astronomy, you could use an airliner flying overhead (or a helicopter for a coarse calibration) to calibrate your microphone array and correct for changes in refraction. An airliner or helicopter will be easy to see with a camera, and of a known size, altitude, and speed.
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This is why you automate it. So you can blind the drone's camera, but be far enough away from the site when the missiles hit. With the right cammo, the detector is only visible when it fires the laser, which it doesn't do unless it hears a drone. Passive surveillance/active response system for asymmetrical warfare.
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"So now the highly directional microphone has to be pointed toward the undetected drone in order to detect it? That makes perfect sense."
Ever seen the rotating antenna of the radar on a boat? That's the reason it rotates.
To detect undetected stuff.
I guess if many people are ordering one of these drone detectors from a cave in Pakistan, it could be a clue that it works.
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A quadcopter at $25k feet? Impressive, that I would like to see.
You can't hear loud noises in the same room with you if you've tuned them out, just because your mind makes it out to be irrelevant background noise doesn't mean that its not there.
The sound can be orders of magnitude lower in amplitude than the noise floor and DSPs can still pick up the signal.
Your cell phone works with far worse signal to noise ratios than a mic finding a drone at 25k vertical.
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I'd think that a distributed passive RF detection system would be more useful.
Just about any aircraft reflects radio waves (even stealth aircraft - they just reflect them away from the transmitter). In theory passive devices could capture RF like a radar and look for reflections, and a bunch of these in different places could determine the position of any aircraft that reflects RF. That would likely have a range much larger than sound.
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The basic hellfire missile (which are the ones they've acknowledged on the drones) has an operational range of 5 miles, 25k feet is less than 5 miles, so it depends on your definition. That would certainly be towards the maximum range, but gravity would help you get some more distance out of it.
Of course, thats just what the government has ACKNOWLEDGED to exist. That basic hellfire spec comes from a missile made in 1985, not sometime in the last 10 years. Between upgrades and the fact that they don't te
Re: Range (Score:2)
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Are missles accurate from that altitude? I would expect the maximum firing altitude to be much lower than the maximum crusing altitude. While the device in question might not help much if you are being spied on by a drone, it seems possible that you could hear one which might be shooting at you soon. It is also worth mentioning that the operating celing is measured in feet above sea level, and a drone flying over the mountains in Pakistan is much closer to the ground.
Well, I think the concern is domestic use, where missiles are unlikely to be a concern.
However, I'd think that a missile would basically have infinite range downwards - it just has to fall. The main issue would be the range at which the seeker could acquire the laser spot. If the missile has gyros (seems likely) it could in theory be just directed along an arbitrary trajectory until it acquires the laser spot as well, which would extend the range beyond what it could actually see. That's what laser-guide
And then what? (Score:1)
You run away?
That's as much of a "shield" as a radar detector "protects" you from speeding tickets.
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You run away?
That's as much of a "shield" as a radar detector "protects" you from speeding tickets.
OK, have it send the e-mail to your next of kin.
Re:And then what? (Score:4, Interesting)
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Well, I suspect that in a few years the thing will basically tell you that there is a drone overhead 24x7. So, those with tinfoil hats basically will end up never going outside.
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A radar detector can protect you from speeding tickets. A laser detector...not so much.
Tough (Score:5, Insightful)
It's tough to reliably detect low-level background repetitive noise without detecting all sorts of nearby domestic appliances, car engines, and such. In the modern city, we live with *alot* of noise.
Now, if the problem is to detect jet engines in rural areas featuring mountainous terrain, then I think I know what the point of this project is.
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It wouldn't be that bad.
Have a 360Â servo with a 80Â-90Â servo mounted on it. Directional mic on top of all that.
Arduino/Pi rotates the first servo 1Â then sweeps the second servo. Or vice versa.
Feed that into an algorithm looking for prop noise. Most drone motors will be IC or electric. An IC will be running between 9K~18K RPM. Electric would be running from 7K on the low end to 30K on the high end. Realistically, an electric for drone use would be on the low end of that spectrum;
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Really, Slashdot? Really?
Those "Â" thingies should have been the symbol for degrees.
And then... (Score:1)
Someone comes along playing the sound of a drone on their smartphone and you realized what a waste of time and money it was.
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Sure, and they'll be able to hold that smartphone up in front of another phone and play modem sounds and they'll be able to communicate at full 56k speeds!
Not really, in both cases.
You can't tell the difference, doesn't mean that the signal processor can't.
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Here you go! [bbc.co.uk] Down near "Sound can be a "two-sided coin" in war, he argues."
Pi fever (Score:3)
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Of course, the Pi is also smaller and uses less power than a mini-itx board. Sticking something the size of a small tissue box in the backyard, and doesn't have an AC cord running into the house, is going to create a lot less friction with the spouse. Many people also find solving problems with constrained resources fun.
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At least it's not an arduino.
Cardinal vs. Mockingbird vs. Bluejay (Score:4, Interesting)
.
Better to use this as an auto-logging device for some birders falling in love with counting how many birdies are coming by, or for recording to the exact micro-second when the swallows [wikipedia.org] finally make it back to San Juan Capistrano [wikipedia.org]!
Re:Cardinal vs. Mockingbird vs. Bluejay (Score:5, Funny)
Hm. That might be interesting. Build a couple and put them a distance apart, plus a remote controlled super soaker. Sit in the basement and pretend it's a sub.
"Skipper, we have a contact on bearing 238... probable squirrel class mammal, likely a grey!"
"Do you have a firing solution?"
"Range and course calculated skipper! Firing solution locked in!"
"Fire!"
"Skipper, sudden change of aspect on the contact. I have angry squirrel sounds."
"Nice job, everybody."
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...someone...please...make...this...
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This is more likely to work better as a "squirrel" vs. "bird" detector, or with good/better datasets, perhaps even as a "cardinal" vs. "bluejay" vs. "mockingbird" vs. "car alarm" detector, especially if the birds are in your front or back yard.
That is a much more practical and marketable idea. Now go build it!
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Hmmm...how about something www.capistranoswallows.com running on a raspberry pi to present a webpage like http://www.abevigoda.com/ [abevigoda.com]
Can't you just detect the RF? (Score:2)
Don't drones blast RF on known frequencies? Unless they're flying with auto pilot and just collecting data, but that would be dangerous in an urban environment with lot's of air traffic. How much would it cost to build something with an antenna that's just listening for broadcasts on these frequencies? You could even measure the doppler shift to see if they're coming or going, and at what speed. Listening for audible noise just seems useless anywhere outside of a big empty desert with a large directional mi
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There are many types of drones. You're thinking of a more radio controlled type. The better ones just have a cellular chip in them and you control them over the internet. Rather than "Fly them" like an RC plane, you give it a target and it goes on its merry way. Once it has its instruction set it doesn't even need the cellular connection anymore, it can just fly back to "home base" once it has done whatever it is it was supposed to do.
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I think they are usually blasting up using sat uplink (military drones). Civilian ones use ordinary RC radios - good luck distinguishing between cordless phone, bluetooth and Fatuba working on 2.4GHz.
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Some talk to a van direct. Great fun if the bad guys ever triangulate the base team
Some long lasting loitering surveillance aircraft with a look down link gets more interesting. But that might be noticed long term.
Other option is a satellite dish like link. Drone only transmits 'up', the van is half a world away.
Long term expect a cheap blimp to sit over an area of interest. Just like a satellite dish link but massive bandwidth and very easy to add more blimps
Almost aut
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I imagine really smart reconnaissance drones would fly their mission then return to a safe zone behind your line to transmit and report home. Real time reconnaissance in an actual combat zone would be supported by the more directly controlled drones in which case finding the controller might be nice, but futile as well.
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Predators and Reapers at least do transmit a satellite video feed which can be picked up from the ground (completely unencrypted, last I heard). So yeah that's one "radio warning sign" that could be worth looking out for. A computer with a TV-tuner-based SDR could detect it. Even if they encrypt the feed, it would be worth knowing about any new satellite video signals that suddenly show up.
Why would I need this when I could have NNS? (Score:2)
Neighborhood Nuclear Superiority!
http://www.youtube.com/watch?v=TGCFmSFvIZw [youtube.com]
Am I the only one who read that as "Meat Drone"? (Score:2)
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Why do citizens have to defend themselves? (Score:2)
Isn't it about time for honest Americans to stand up and say "I d
better idea (Score:4, Funny)
You Have Mail (Score:2)
"Warning: Predator drone detec---"
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Or the (on average) roughly 18 innocents that are killed with them in each drone strike...but you hate all Muslims so this should please you.
Well Muslims frequently use human shields but I really can't be pleased about people who may not have followed the instructions of their religion being killed.
Yeah, right (Score:2)
Predator drones use a common small aircraft engine used on about 30 other small aircraft. Similar Rotax engines are used in snowmobiles, jet skis, go-carts, and other small engine applications.
You're going to get an alarm every time something with a small engine goes by, and you probably won't pick up an aircraft flying high enough to not be blatantly annoying.
If you want to detect nearby aircraft, build a radar. There are automotive anti-collision radars that could be adapted.
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It would be fun to build a small radar array with a synthetic aperture antenna so you could tell the difference from let's say a Cessna 152 flying by and a drone. The next step would be to use the spacial information to aim a small high performance maser to fry the electronics on said drone (of course, only if it was invading your privacy.) It would be entertaining for the drones' owners to find in post mortem that their sky spy was a crispy critter.
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There aren't many snowmobiles, jet skis, or go-karts operating in the areas where drones are operating. Especially in the air.
At the same time, I don't believe that audible signals would be effective since a drone operates several miles above the ground surface.
What is needed for drone detection and identification is a wide-angle magnified video camera that scans the sky (basically the same thing as the Predator uses on its targets). A Predator is about 27x48 feet (length x wingspan), at 20x magnification
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There aren't many snowmobiles, jet skis, or go-karts operating in the areas where drones are operating. Especially in the air. I got a great chuckle out of this one =)
The camera's needed would maybe be a lot more expensive then your standard 3-6 megapixel cheap ones. Once you start getting into good resolutions and light adaptability. It starts getting harder. Then again maybe an array of off the shelf webcams could do the trick, but that requires group participation and you think people are mad now about g
Why? (Score:2)
Apart from hobby drones (like quadcopters) it's fairly limited what drones you'll encounter around where you live. Unless you live where the wild Predator drones roam... there you'll most likely hear the sound of missiles detonating before you hear the drone itself.
Obligatory xkcd (Score:2)
Supersonic (Score:2)
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Nothing short of a Soviet Workers America can stop the genocidal depradations of the killer gang of Wall Street/Washington.
Hopefully better spelling will be a natural consequence of said recolution.
Ah, spelling. I was wanderg why he wanted to de-Prada his new Soviet state.
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At least the tools of the fifth column are kept busy with an imaginary problem...
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It's easy to reduce gun violence. Just reduce the inequality in society.