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#52
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Defense against UAV's
wrote in message oups.com... Keith W wrote: If you are using video imaging (backed up by some other, e.g. IR/passive EM sensors), I suspect it is a graduate student's exercise in image recognition to distinguish a warship (esp. aircraft carrier) from an oil rig/tanker/finshing ship. Especially if you are flying slow. As a software engineer I'd suggest you are wrong. If such recognition is so easy how did an Argentine aircrew drop bombs on an American tanker in 1982 believing it was a RN Carrier ? Scared ****less of being shot down? The Argentine air crews displayed almost suicidal bravery Wishful thinking? Orgasmic about being able to release their weapons and claim kills? Darkness/lousy weather/bad visibility? Daylight Flying fast and having only few short seconds to make decision? In a C-130 ? Releasing their weapons from way too far range for positive identification (perhaps because being scared ****less)? They rolled them off the exit ramp at mast top height Can be any of these or their combination. Or just maybe its harder than you think. A UAV with realtime video image recognition and IR sensors is unlikely to be especially cheap Realtime video image recognition needs a source of video (probably a wide-angle search camera + narrow angle scope with some decent magnification for examining the suspicios contacts), Problem 1 ) You have to process them to decide if they are suspicious a decent CPU to do the number crunching and a software to do the analysis. The first two items are not particularly expensive. The software might take real pains to develop, but afterwards the copies are free. Understatement of the year Perhaps the costliest part of the development would be sea trials (to see how is the real-time identification working and debug it), but then who knows what they use their small UAVs for now (see the first message of this thread). Who knows if the incident even happened. snip 200 km/hr UAV's are going to be rather vulnerable to all forms of active defence including point defence missiles like RAM and to CIWS. Yes. That's why you want them to be really cheap and use swarming. With real time image recognition systens cheap will be quite a trick. The cost might be high for initial development, but there is not reason the cost should be high on per-unit base. Cameras/CPUs and copying software is cheap. Cooled IR sensors and other fancy sensor stuff might rise the cost - the question is how much of it is needed, especially if you don't ask for all-weather capability. All of it or it wont work On the other hand RAM is IR homing and the IR signature of a 100hp piston engine is negligible compared to the IR signature of a rocket/jet engine of the current antiship missiles. But not small enough to be invisible Nothing is invisible. But if its signature is there with seagulls and sun reflections off waves, the locking/homing task is so much harder. Seagulls dont have 100 hp engines. Even cheap IR sensors have no problem with people let alone IC engines Phalanx (or other gun-based CIWS) should be effective, but has rather short range (and not THAT much reloads, if you are dealing with a huge swarm). I suspect it is also looking at targets with much higher radar signature and very different characteristics. Thats just software and rather easier to do than deciding if that 1000 ft long ship is a carrier or VLCC An attacking UAV can make its decision to attack close enough - when it can actually see the island/aircrafts on deck of the carrier. First it has to decide to get close enough, then it has to survive the transit And has a lots of frames to base its decision on. It might even send some info to the controller and ask whether to attack or not (again, tradeoff between how much you send and how reliable you want your communication channel to be). Comms are BAD things for an autonomous UAV , they can be jammed The CIWS mounts look rather distinctly and will obviously be among the targeted areas of the ship. You don't need that much of a warhead to put CIWS radar ot of commission - so perhaps an UAV with 200kg warhead can actually carry 8-12 short range missiles designed for homing on CIWS radar and launch them while being out of range of CIWS. Earth Calling Planet Esteban - a UAV with 200kg warhead and 8-12 sub missiles will be neither small nor cheap. Such an UAV will not be small: it will be Predator size, powered by a Rotax, Jabiru or more likely cheap copy of them. None of which carry 8-12 sub missiles. Note that controlling Predator involves 3 operators in a 30ft trailer packed with electronics But it can be cheap, especially if mass produced and intended for one-way cruise-missile type missions. Not with the abilities you are demanding. Ultralight aircraft kits are essentially hand-made and sell for 10-20k. Indeed but of course they fly a around 70 knots with a max gross weight of around 300 kg, not much room there for 200kg warheads Replace the cabin with the warhead(s), give it faster wing (no need for low stall speed, this is on one way mission) and the sensors/brains/communication kit and mass produce it. Real easy huh , when do you plan to start production ? Be smart designing it (ease of mass production) and try to reduce the IR/radar signature, but don't go overboard with that - keep the costs down. The only potentially expensive parts on the aircraft are sensors and warheads. The 200kg is the total useful load, some UAVs will have it divided as sub missiles for massed attack on air defense radars, other UAVs will simply have a big explosive load (hoping that the radars have already been damaged, so they can get in close to do BAM). ... simple systems are easier to debug/design correctly). However, a country like China/India or even Iran should be able to mass produce good enough UAVs for peanuts (i.e be able to field thousands of them). The key term being 'good enough', not 'super duper, all weather, high reliability and long service life'. But with real time image recognition, organic SEAD and large warheads Yeah, you need real time image recognition. That is the enabling technology. I think we can agree to disagree whether that is possible in the next 5-10 years, for operation in good visibility. The quoted 200kg was just quoted as an example - about what an ultralight aircraft can carry. You need your aircraft big enough to have enough range to engage the carrier group operating off your shores, so a 200kg payload will not significantly increase it anyway. A modified ultralight can't fly that fast, leaving it rather vulnerable. I think I already said that That's why you are better of launching submunitions from out of range of the gun CIWS. Those subminitions need to be reasonably smart (once qued by the sensors of the main craft, they need to be able to lock on their target and hit it), but not necessarily pack a lot of punch (hitting radars, aircraft on deck and so on). Hint CIWS reach a long way , the sort of missile you'd need would be stinger sized at a minimum and you need a control system smart enough to know WHEN to fire, sensor fuzion is harder than you seem to think Once the radars have been damaged, the second wave can then just press on with large warhead bringing general destruction. (Or, to keep it simple, they all go together. If the radars are switched off, the large warheads will arrive and do the damage, if the radars are on (likely), the submunitions will home on them.) So you now rely on a new development of small fast radar homing sub munitions as well, and all this a grad student technology , yeah right ! Keith |
#53
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Defense against UAV's
"Keith W" wrote in message ... wrote in message oups.com... Keith W wrote: If you are using video imaging (backed up by some other, e.g. IR/passive EM sensors), I suspect it is a graduate student's exercise in image recognition to distinguish a warship (esp. aircraft carrier) from an oil rig/tanker/finshing ship. Especially if you are flying slow. As a software engineer I'd suggest you are wrong. If such recognition is so easy how did an Argentine aircrew drop bombs on an American tanker in 1982 believing it was a RN Carrier ? Scared ****less of being shot down? The Argentine air crews displayed almost suicidal bravery Are these exclusive? Glenn D. |
#54
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Defense against UAV's
"Glenn Dowdy" wrote in message ... "Keith W" wrote in message ... wrote in message oups.com... Keith W wrote: If you are using video imaging (backed up by some other, e.g. IR/passive EM sensors), I suspect it is a graduate student's exercise in image recognition to distinguish a warship (esp. aircraft carrier) from an oil rig/tanker/finshing ship. Especially if you are flying slow. As a software engineer I'd suggest you are wrong. If such recognition is so easy how did an Argentine aircrew drop bombs on an American tanker in 1982 believing it was a RN Carrier ? Scared ****less of being shot down? The Argentine air crews displayed almost suicidal bravery Are these exclusive? Not at all Keith |
#55
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Defense against UAV's
In article .com,
says... Andrew Swallow wrote: Many UAVs are flown under remote control. Radio direction finding may permit the location of its headquarters to be found. Good point, few countries have enough satellite bandwidth to manage UAVs the way the US does, so unless Iran is buying bandwidth from someone else, they'd have to be RC controlled UAVs. Fully autonomous UAVs are not common today---but they probably will be in another few years. They would be particularly good for surveillance of large targets like a CVBG. The UAV could send out data and wait for very generic microburst commands like "circle left, 20mile radius". That would make it hard to attack the controller. While it may be possible get a DF location on a randomly-timed, 10millisecond, spread spectrum signal from a mobile command post, it might also be very expensive. That would make the controller VERY vulnerable to counter fire and would severly limit range. It would also make the control of the UAV somewhat easy to jam, or even commandeer. I would expect that military UAVs would have fairly good encryption on the links. Heck, even the low-cost ($179) 900 MHz modems we use on some projects feature frequency hopping and 256-bit AES encryption. http://www.maxstream.net/products/xt...odem-rs232.php Mark Borgerson |
#56
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Defense against UAV's
wrote in message oups.com... wrote: An Iranian UAV was able to circle a U.S. aircraft carrier undetected for 25 minutes. How can we protect our forces against UAV's when other countries or terrorist organizations start using them against us? Carrier launches it's own swarm of 1/6 scale Hellcats to cut the intruders' crepe-paper streamers with their props... Finally someone's thinking straight. Personally I'd forget all the high-tech stuff and go for an old WWII carrier with Seafires on it. No swarm of UAVs can match that, plus all the WWII pilot wanabees get to fly. If a flight is sent to intercept a flock of birds, oh well, at least they've flown. If they come across hostile UAVs its time to check the lightbulb in that good old reflector gunsight and go weapons hot. |
#57
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Defense against UAV's
In article . com,
says... wrote: Jack Linthicum wrote: wrote: If the report on the Iran UAV is accurate, the USN is evidently not on top of this at present. I hope they are working on it, very hard. Like anti-radiation missiles. Against the launch sites and control points. Since only a simple radio signal is needed to control the UAVs (and then not all of the time - only when they want to instruct them to do something) that would be very much harder than hitting a high-powered radar which has to keep transmitting a distinctive signal all of the time to do its job. And AR missiles could easily be decoyed by lots of cheap radio transmitters scattered about. The problem here is that it could be a kind of 'asymmetric warfare', in that the costs and problems of the defence are potentially far more costly than those of the attackers. Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk The mention was of swarms which implies swarms of signals which then implies if I have an ECM craft up and I get lots of radiation from one direction I will send a message to that source. The decoys may work the second time but not the first or third. The control point will be that, singular, one command directing all of the UAVs from one spot. How many generals would you trust if you were Mahmoud Ahmadinejad? One control point for a swarm of semi-intelligent UAVs does not imply either continuous transmission or a single transmitter. Mark Borgerson |
#58
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Defense against UAV's
In article .com,
says... wrote: Jack Linthicum wrote: ... The mention was of swarms which implies swarms of signals not necessarily, if mostly autonomous UAVs are used which then implies if I have an ECM craft up and I get lots of radiation from one direction I will send a message to that source. The decoys may work the second time but not the first or third. ?? The control point will be that, singular, one command directing all of the UAVs from one spot. Ever heard of fiber optics communications? Set-up multiple cheap antennas for communication, and link them with fiber optics to your safe hidden command centre. Why you guys always assume that the bad boys are dumb beyond recognition alludes me... What the hell is an autonomous UAV? Well, a semi-autonomous UAV is one that doesn't require continuous flight-control command. It simply requires comms more on the order of those with a fighter pilot: "Target in sight" "cleared to fire", etc. and to what purpose? You need a unique signal for each aircraft otherwise they will all turn left at the same time. Nope. You just need a different packet address for each UAV. On the first shot you may hit a bunch of decoys but also the target or targets. Especially if the decoys must be deployed under the control of the central command. Second time the decoys may stay on and the command freqs shut down. Third time no one cares and fires enough weapons to take care of the site and the decoys. How many rounds does the defense need to destroy all those decoys and targets? I have heard of fiber optic communications, those antennas will still radiate and believe it or not the U.S. military can figure out where the command point is physically. The bad guys do not have to be smart or dumb, they will be overwhelmed by the amount of crap the U.S. can throw at tem. It's the occupation afterwards that is the sticking point. Yup. Then the US military will be overwhelmed by the amount of crap the insurgents throw at them! ;-( The guys on land are having problems countering modest numbers of low-cost, command detonated munitions. The Navy has the advantage of greater standoff range-- but loses a lot of that advantage as soon as it comes time to put boots on the beach. Mark Borgerson |
#59
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Defense against UAV's
Keith W wrote: Can be any of these or their combination. Or just maybe its harder than you think. Somehow I doubt when they were overflying the tanker in daylight, they still thought they are attacking an aircraft carrier. :-) A UAV with realtime video image recognition and IR sensors is unlikely to be especially cheap Realtime video image recognition needs a source of video (probably a wide-angle search camera + narrow angle scope with some decent magnification for examining the suspicios contacts), Problem 1 ) You have to process them to decide if they are suspicious There are not so many big things floating in the ocean, just examine them all. While the waves move and provide clutter, in half-decent weather a 100m+ ship tends to stick out as a sore thumb from quite afar. And it is quite unlikely there will be third party merchants sticking around a US carrier group in time of armed conflict.... a decent CPU to do the number crunching and a software to do the analysis. The first two items are not particularly expensive. The software might take real pains to develop, but afterwards the copies are free. Understatement of the year Yes, if you want to be able to do it in all weather, from 50km+ afar, your target hidden among the merchants, in few moments of ultrasonic flight. In fair weather, from less then 15km, with closing speed of 200km/h, I am not so sure. Warships do look quite differently then merchants/oil rigs, and they also tend to radiate differently. With real time image recognition systens cheap will be quite a trick. The cost might be high for initial development, but there is not reason the cost should be high on per-unit base. Cameras/CPUs and copying software is cheap. Cooled IR sensors and other fancy sensor stuff might rise the cost - the question is how much of it is needed, especially if you don't ask for all-weather capability. All of it or it wont work See above. Fair weather, no clutter. You want sensors from different spectra to work together, but they can be the cheap stuff... On the other hand RAM is IR homing and the IR signature of a 100hp piston engine is negligible compared to the IR signature of a rocket/jet engine of the current antiship missiles. But not small enough to be invisible Nothing is invisible. But if its signature is there with seagulls and sun reflections off waves, the locking/homing task is so much harder. Seagulls dont have 100 hp engines. Even cheap IR sensors have no problem with people let alone IC engines With the engine tucked at the back (like Predator) and with good mixing of the exhaust gas, you are mostly looking at cold front face. Seagulls/people tend to present warm bodies. Moreover, those cheap sensors are not mounted on supersonic missiles screaming to intercept you (the heat of the supersonic air alone might wash out your meager IR signature). Phalanx (or other gun-based CIWS) should be effective, but has rather short range (and not THAT much reloads, if you are dealing with a huge swarm). I suspect it is also looking at targets with much higher radar signature and very different characteristics. Thats just software and rather easier to do than deciding if that 1000 ft long ship is a carrier or VLCC An attacking UAV can make its decision to attack close enough - when it can actually see the island/aircrafts on deck of the carrier. First it has to decide to get close enough, then it has to survive the transit First is not that tough - with enough endurance reserve. Second is the matter of identification distance. And if the suspected target is illuminating me with targetting radar, I don't really have problem to identify it as a target, even if I am relatively far. And has a lots of frames to base its decision on. It might even send some info to the controller and ask whether to attack or not (again, tradeoff between how much you send and how reliable you want your communication channel to be). Comms are BAD things for an autonomous UAV , they can be jammed Yes - but low bandwith intelligently designed comms are tough to jam. Earth Calling Planet Esteban - a UAV with 200kg warhead and 8-12 sub missiles will be neither small nor cheap. Such an UAV will not be small: it will be Predator size, powered by a Rotax, Jabiru or more likely cheap copy of them. None of which carry 8-12 sub missiles. Useful load of Predator is about thousand pounds. A hellfire is more useful for predator then 8-12 short range anti-radar missiles. Note that controlling Predator involves 3 operators in a 30ft trailer packed with electronics Predator does a lot more, and the operators/electronics are there to analyze/evaluate what it sees, in a much harder to analyze environment, and with much higher expectations. Ultralight aircraft kits are essentially hand-made and sell for 10-20k. Indeed but of course they fly a around 70 knots with a max gross weight of around 300 kg, not much room there for 200kg warheads Ultralights with 100hp engines are limited to cca 500kg and 100knots by law, not by physics. Predator uses the same 100hp Rotax and has 220km/h max speed, around 1000kg takeoff weight of which cca 500kg is dry weight (200payload, 300 fuel). That 500kg of dry weight also includes lots of sensors you will do without. Replace the cabin with the warhead(s), give it faster wing (no need for low stall speed, this is on one way mission) and the sensors/brains/communication kit and mass produce it. Real easy huh , when do you plan to start production ? The tough part is really the sensors/data analysis, not the airframe.... That's why you are better of launching submunitions from out of range of the gun CIWS. Those subminitions need to be reasonably smart (once qued by the sensors of the main craft, they need to be able to lock on their target and hit it), but not necessarily pack a lot of punch (hitting radars, aircraft on deck and so on). Hint CIWS reach a long way , the sort of missile you'd need would be stinger sized at a minimum and you need a control system smart enough to know WHEN to fire, sensor fuzion is harder than you seem to think Stinger missile proper weights 10kg, plenty of room in my 200kg allowance for 8 of them. Somehow identifying the range to the target (when you are within line of sight and less then 10km away) does not seem too hard to me. Knowing that I am being illuminated by targeting radars also helps in making my decision. Once the radars have been damaged, the second wave can then just press on with large warhead bringing general destruction. (Or, to keep it simple, they all go together. If the radars are switched off, the large warheads will arrive and do the damage, if the radars are on (likely), the submunitions will home on them.) So you now rely on a new development of small fast radar homing sub munitions as well, and all this a grad student technology , yeah right ! No, being India/China/Iran, I already have those - maybe a bit larger, but no significant new development needed. Keith |
#60
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Defense against UAV's
Jack Linthicum wrote: Mark Borgerson wrote: In article . com, says... wrote: Jack Linthicum wrote: wrote: If the report on the Iran UAV is accurate, the USN is evidently not on top of this at present. I hope they are working on it, very hard. Like anti-radiation missiles. Against the launch sites and control points. Since only a simple radio signal is needed to control the UAVs (and then not all of the time - only when they want to instruct them to do something) that would be very much harder than hitting a high-powered radar which has to keep transmitting a distinctive signal all of the time to do its job. And AR missiles could easily be decoyed by lots of cheap radio transmitters scattered about. The problem here is that it could be a kind of 'asymmetric warfare', in that the costs and problems of the defence are potentially far more costly than those of the attackers. Tony Williams Military gun and ammunition website: http://www.quarry.nildram.co.uk The mention was of swarms which implies swarms of signals which then implies if I have an ECM craft up and I get lots of radiation from one direction I will send a message to that source. The decoys may work the second time but not the first or third. The control point will be that, singular, one command directing all of the UAVs from one spot. How many generals would you trust if you were Mahmoud Ahmadinejad? One control point for a swarm of semi-intelligent UAVs does not imply either continuous transmission or a single transmitter. Mark Borgerson I think that a spread spectrum burst type transmission can be intercepted and given a rough bearing. The money to do this is miniscule in comparison with making Trident missiles into hand grenades. Hm, I don't know. Especially if they employ hundreds/thousands of battery/solar powered decoy transmitters. You will need to listen on the whole spectrum, all time, and be able to sort out what is real and what is noise. Still have to transmit to the aircraft, whether it is a high sophisticated address or not the transmission has to be made to each aircraft. No, a broadcast to the whole group is enough. Home on radiation. The radiation is almost never there (short bursts from different locations). You will need to remember the bearing/location of the burst, then examine that neighbourhood for anything suspicious and then perhaps attack it. With decoy transmitters .... good luck! Again the idea that the position in which a large scale use of UAVs is analogous to the IED situation is not defensible. Multiple targets are multiple targets to an airborne system. So far I see this whole discussion as one of a possible but not probable situation. Tough to say what is probable. What is certain is that the potential adversaries are not stupid, and they are searching assymetric ways how to neutralise the US military advantages.... |
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