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Czech Passive Radar Detecting B-2 at 150 miles (2015)
- mikeyouse 7y agoThey do claim it works on all stealth planes including the F-35, but the B-2 is now 30 years old and was designed in the mid 1980s. Detecting it from 150 miles is impressive, but when they're equipped with 250 mile standoff air-to-surface missiles, ultimately not very useful. I'd be curious how much better the stealth is in the world of supercomputers and CFD for modern planes as well.
- LifeLiverTransp 7y agoThose missiles will help you how though? They are mostly radar seeking for target information.. this doesent emit though. This only collects. So you need reconissence by drones ( easily detected with this) .. Sorry, but this literaly breaks a billion dollar technology. Due to the distributed nature of the natural sources, it doesent matter what angle you reflect - a stealthed object will always be a distortion to the background, which alot of computation can the filter out.
- kabouseng 7y agoWell it's passive radar. So you don't have to outperform the stand-off range of the target, since you are invisible to the plane too.
- nitrogen 7y agoIs there any risk of demodulator IF or other leakage from these receivers?
- amluto 7y agoGiven that it’s entirely reasonable to build a 3 GHz baseband receiver these days, you don’t need IF. The whole thing can probably be made to radiate almost indistinguishably from a cell phone or computer.
- londons_explore 7y agoA cell phone moving at that kind of speed will stand out.
- nitrogen 7y agoWould a passive radar usually be moving?
- deleted 7y ago[deleted]
- HumblyTossed 7y ago> ...but the B-2 is now 30 years old and was designed in the mid 1980s. Given that the B-52 is 65 years old, built with 1955's technology, I would expect something more sophisticated to have a longer shelf life than 30 years.
- WalterBright 7y agoThe B-52 is only useful after the enemy's air defense systems have been completely suppressed. It's mostly just a truck.
- nradov 7y agoThe B-52 can also carry long range stand off weapons.
- catalogia 7y agoThat's not how it works. There are loads of planes much younger and more sophisticated than the B-52 which are no longer in service. To name just a few high profile examples: the SR-71, F-117, and Space Shuttle.
- madengr 7y agoNot much. The F-117 is stealth mostly due to shape. The B2 stealth is mostly due to materials and construction techniques. You can run optimization routines to reduce scattering, but it’s not going to be huge improvements This is a good book that discusses several techniques: https://www.amazon.com/Radar-Man-Personal-History-Stealth/dp/1450248020/ref=nodl_ https://www.amazon.com/Radar-Man-Personal-History-Stealth/dp...
- nabla9 7y agoB-2 is old but the stealth shaping is still much better than F-35 and there is much more internal structure inside the wings that absorb radar energy. The RAM paints used in B-2 are probably up to date with current technology as well. B-2 is also inherently more stealthy to to Rayleigh scattering than F-35 is due to the size. Stealth is not magic. Shaping is 90% of the stealth, rest is the materials and details. Vera-type radars may be be able to detect stealth aircraft with low angular resolution but they can't be used for targeting.
- whalesalad 7y agoThe B2 is relatively ancient as far as stealth tech goes. Also, most stealth aircraft are detectable on radar. The question is how big or small is the radar cross section. That’s not something this blog post digs into. Meaning, most of the time a B2 looks like a goose or a small animal. Correction on my part: The B-2 and F-35 have radar cross sections roughly the size of a marble.
- willvarfar 7y agoA goose flying at 600mph?
- HumblyTossed 7y agoIt could happen: https://en.wikipedia.org/wiki/Chicken_gun https://en.wikipedia.org/wiki/Chicken_gun
- dmos62 7y agoIn that vein: cold-war era chicken-heated nuclear bomb (for area denial) https://en.wikipedia.org/wiki/Blue_Peacock#Chicken_power https://en.wikipedia.org/wiki/Blue_Peacock#Chicken_power
- GekkePrutser 7y agoOh dear.... Never heard of this but I'm glad the cold war is over. "Alright chaps, let's bury some 10 kiloton nuclear mines in Germany in case the Russians come.", From wikipedia: "deny occupation of the area to an enemy for an appreciable time due to contamination" "It was judged that the risks posed by the nuclear fallout and the political aspects of preparing for destruction and contamination of allied territory were too high to justify. " Ummmmmm yeah WOULD YOU THINK??? "One particularly remarkable proposal suggested that live chickens be included in the mechanism. The chickens would be sealed inside the casing, with a supply of food and water; they would remain alive for a week or so. Their body heat would, it seems, have been sufficient to keep the mine's components at a working temperature." Ok...... Now I'm really wondering if the Soviets were the crazy ones.
- galacticaactual 7y agoThere is no evidence in the article to assert a B-2 was actually detected at 150 miles outside of unverified claims.
- DailyHN 7y ago2015
- anonu 7y agohttps://en.wikipedia.org/wiki/Passive_radar https://en.wikipedia.org/wiki/Passive_radar In a passive radar system, there is no dedicated transmitter. Instead, the receiver uses third-party transmitters in the environment, and measures the time difference of arrival between the signal arriving directly from the transmitter and the signal arriving via reflection from the object. Passive radar systems have been developed that exploit the following sources of illumination: Analog television signals FM radio signals Cellular phone base stations Digital audio broadcasting Digital video broadcasting Terrestrial High-definition television transmitters in North America GPS satellites (GPS reflectometry).
- jcims 7y agoYou can build your own with rtl dongles and lots of patience - https://www.rtl-sdr.com/building-a-passive-radar-system-with-an-rtl-sdr/ https://www.rtl-sdr.com/building-a-passive-radar-system-with...
- lazyjones 7y agoWhat would air defence against a swarm of a few 1000 UAV look like? Because China...
- Retric 7y agoDrones represent a huge range of different things. Assuming you mean something that’s a replacement for military aircraft. In order to have a useful X,000miles range and useful payload you need to build fairly large drones which means a large target. If their cheap that directly translates into low speeds making them a very easy target for anti air guns, or low cost anti aircraft missiles. If you want a large fast drone, that’s getting expensive. To the point where having or not having a pilot makes minimal cost differences. Note, this assumes it’s part of a modern war with extreme radio jamming etc.
- rblatz 7y agoWhy would you not deploy smaller drones via another platform? Small cheap disposable drones are a game changer. Drop them on a military base and have them seek and distort any human shaped targets, any sources of RF radiation, anything that looks like a vehicle or plane...
- chmod775 7y ago> Drop them on a military base If you can get close enough to drop a bunch of slow drones, you can get close enough to just drop a bomb on the whole thing instead. Much more bang for your buck. Let's also not forget that small drones might become 'banned' much like chemical weapons did, if they ever became viable.
- nradov 7y agoSmall drones will never be banned by international treaty. There is zero chance of that.
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- spiderfarmer 7y ago2016: https://www.cnbc.com/2016/09/21/the-end-of-stealth-new-chinese-radar-capable-of-detecting-invisible-targets-100km-away.html https://www.cnbc.com/2016/09/21/the-end-of-stealth-new-chine...
- KingOfCoders 7y agoI think the current anti stealth capabilities are not clear, countries that use anti stealth radar are not talking about the capabilities, e.g. what does "The superior stealth target tracking capabilities ensure optimal performance in demanding littoral environments." mean https://www.thalesgroup.com/en/netherlands/news/new-fire-control-radar-7-french-navy-frigates https://www.thalesgroup.com/en/netherlands/news/new-fire-con... or "Within this enormous range it detects a wide spectrum of targets: air breathing targets, stealth targets and ballistic missiles." https://www.thalesgroup.com/de/smart-l-multi-mission-radar-0 https://www.thalesgroup.com/de/smart-l-multi-mission-radar-0 or "It is also claimed to be highly capable of detecting stealth targets" https://en.wikipedia.org/wiki/S1850M https://en.wikipedia.org/wiki/S1850M
- baybal2 7y ago> "performance in demanding littoral environments" This is a defence contractor 1337 sp33k for "Works well in the South China sea"
- ChuckMcM 7y agoHmm, not your typical RADAR. This is basically using the RF emissions of the plane, and their detection at multiple RF detection stations with synchronized clocks, to determine the difference in arrival time. The radio emissions all travel at the same speed through the air, the difference in arrival time can be used with some simple trig to figure out where the RF emitter is. There are a number of Time Difference of Arrival or TDOA systems out there. It is why I expect aircraft stop using their radios when they are about to engage their targets. That said, they are "easy" to jam in the sense that when you have two radio signals on the same frequency, they will interfere with direction finding. And there is a lot of noise in the RF spectrum out there, especially during thunderstorms.
- catalogia 7y ago>multiple RF detection stations with synchronized clocks, to determine the difference in arrival time. The radio emissions all travel at the same speed through the air, the difference in arrival time can be used with some simple trig to figure out where the RF emitter is. That's a fancy way to say 'triangulation'.
- fest 7y agoI believe it's technically trilateration, not triangulation.
- coretx 7y agoContemporary passive radar arrays are phase sensitive so it ain't that simple either.
- rmattes 7y agoIt would be triangulation if the system was measuring the arrival angles of the incoming signals. If the system relying solely on arrival time differences, it's likely doing something based on trilateration.
- jah 7y agoHere's an interesting variation that uses RTL-SDR's: https://dopplerfish.com/passive-radar/ https://dopplerfish.com/passive-radar/
- whalesalad 7y ago> Jamming hard and almost impossible to be destroyed by the anti-radiation missiles kill radar. Positioning and stick to the target in the air, on land and sea surface perfectly, providing enough parameters in real time. This post is really quite garbage.
- LyndsySimon 7y agoThat reads like a badly-translated press release. I don’t buy it.
- stevespang 7y agoThat's why US has HARM missle. First operation is to send in aircraft along the "fringes" with HARM missle to take out any and all radar sites. Then, enemy fighters don't have such radar to detect stealth US aircraft.
- rich_sasha 7y agoThere is also a matter of accuracy. I believe stealth planes are often “detectable” at longer frequencies, which however do not give precise enough information to fire a missile at them. So you’ll know they are coming but can’t shoot them down. I would imagine radio signal triangulation falls into a similar category.
- nradov 7y agoMany people fail to understand that there's a huge difference between detecting the presence of an aircraft and actually targeting it. Anti-aircraft weapons must be precisely targeted to have any chance of hitting. So a passive radar can be useful in limited circumstances for cueing other sensors but it can't accomplish much by itself.
- m4rtink 7y agoCould the adversary still just send cannon equipped fighters to the general that would locate the stealth bomber visually and shoot it to pieces ? Sure, could be rather hard to do in the night but once a stealth bomber is sighted visually, it is toast - B2 simply has no self defence weapons available at all. A stealth fighter could be better off if it can defend itself while still avoiding others getting a weapon lock, effectively forcing them to use visually sighted cannon while it can use sensor guided gun and missiles normally.
- sfifs 7y agoThe B2 especially is huge (there's one on display in Dayton) and likely slow. If it's been localized to within a few km or so, it's probably a sitting duck to any reasonably modern air force.
- computerex 7y agoThere is no way a B2 will be deployed without at least a couple fighters escorting it.
- ivalm 7y agoIf it has fighters escorting it then it is not invisible.... whole point of B2s is to be invisible to long range radars (due to plane geometry). F22 and F35 don’t have this capability.
- nradov 7y agoThat's the type of tactic that mostly only works in movies. In the real world interception is very, very hard just due to geometry. Fighters have limited fuel supplies and don't move much faster than bombers. Any no country can afford to keep a lot of them in the air or even on alert status at any given time. So the circumstances have to line up pretty well to get an interceptor in the right place at the right time. And even then, aircraft like the B-2 are difficult targets to actually hit. At high altitudes they are fairly maneuverable due to low wing loading.
- enigmabridge 7y agoYou don't necessarily need the aircraft to emit any signals, you may be able to detect changes in the background RF emissions reflected or distorted by the aircraft. It would have to be enormously CPU expensive but if you can correlate changes in tens or hundreds of frequencies, I can imagine it could be done.
- thedance 7y agoWhat's the mission and purpose of the B-2 these days? It's a penetrating strategic bomber. The justification for it was that it could strike mobile Soviet ICBM launchers. It was never going to be any good for that. What's it for now? Has it ever been used against a sophisticated enemy (i.e. not people who are literally living in caves)?
- gsnedders 7y agoIt's combat debut was during the Kosovo War, which was clearly _not_ people who are literally living in caves, during which the F-117 suffered its only combat loss, shot down by anti-aircraft missiles, successfully tracked by the radar.
- thedance 7y agoOK, but what's it good for today? Kosovo was 20 years ago. If the B-2's role is to fly conventional missions, the MQ-9 can be armed with the same weapons that the B-2 carries.
- openasocket 7y agoGetting inside an integrated air defense network to take out strategic targets. It's got what is believed to be a better stealth profile than the f-22 or f-35, while having payload comparable to a b-52. The MQ-9 wouldn't be able to get anywhere close to an air defense network.
- thedance 7y agoOK I'm convinced. What's the 52 for, then?
- openasocket 7y agoLarge scale strikes also, but after air defenses have been taken down, or suppressed by SEAD escorts. Keep in mind we only have 21 B-2s and they are very expensive to maintain, so it makes sense to use the B-52 whenever possible.
- exabrial 7y agoA lot of countries posses radar that can detect stealth aircraft in a certain area, but cannot be used to create a fire solution or even narrowing it down to an area more than a couple square miles. I believe as a design tradeoff, these planes are much more "invisible" (lower radar cross section) at tracking and targeting radar wavelengths, which must use much smaller frequencies.
- GekkePrutser 7y agoWho wrote that article? It reads like Chinese that was put through a bad version of google translate. I mean really who uses 'cum' in an official article (even though it's not in an NSFW context and technically used correctly). It's a word that has fallen into disuse because its 'other' use has taken over its association entirely :) You won't find this in a serious publication. And this "Distance reconnaissance: 400 km with 20 m wrong; Number of goals can stick to 200 targets simultaneously." Whatever it is, this ain't English.
- frandroid 7y agocum qa become remains in common use today.
- GekkePrutser 7y agoI really haven't seen it in that context for the last 15 years or so :) Maybe it's just me :) But really the whole article reeks of Engrish, it's not just that.
- clouddrover 7y ago> I mean really who uses 'cum' in an official article (even though it's not in an NSFW context and technically used correctly). English speakers. > You won't find this in a serious publication. Won't I? Then let's search for such usage: - Seems serious: https://www.nytimes.com/roomfordebate/2015/09/02/whats-the-greatest-threat-to-us-national-security/americas-mindset-is-the-greatest-threat-to-its-future https://www.nytimes.com/roomfordebate/2015/09/02/whats-the-g... - Seems philosophical: https://opinionator.blogs.nytimes.com/2015/02/02/how-to-be-a-stoic/ https://opinionator.blogs.nytimes.com/2015/02/02/how-to-be-a... - Seems like all publicity is good publicity: https://www.theguardian.com/cities/2018/mar/26/braunau-spotlight-austria-hitler-birthplace https://www.theguardian.com/cities/2018/mar/26/braunau-spotl... - Seems expensive: https://www.wsj.com/articles/the-force-is-strong-inside-this-l-a-mansion-with-star-wars-themed-basement-11579719948 https://www.wsj.com/articles/the-force-is-strong-inside-this... - Seems fashionable: https://www.washingtonpost.com/lifestyle/2020/03/01/paris-fashion-week-balenciaga-balmain-celine/ https://www.washingtonpost.com/lifestyle/2020/03/01/paris-fa... - Seems Swiss: http://www.bbc.com/travel/story/20170717-the-country-that-cant-choose-a-side http://www.bbc.com/travel/story/20170717-the-country-that-ca... - Seems like a headline: https://www.bbc.com/news/world-africa-24960219 https://www.bbc.com/news/world-africa-24960219
- baybal2 7y ago150 miles is not that much