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    Russian Radar systems

    kvs
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    Post  kvs on Sat Oct 03, 2020 5:07 pm

    Gomig-21 wrote:Besides the marketing information like this:

    Rezonans radars operate in the meter band and employ the principle of wave resonance, which allows detecting aircraft based on stealth technology and also hypersonic targets flying at a speed of up to Mach 20. The radar is capable of detecting targets and issuing target acquisition on aerodynamic targets at a distance of 600 km and at a range of 1,200 km on ballistic targets, at an altitude of up to 100 km.

    How does resonance effect actually identify an F-35 for example?  Using "meter band employing the resonance effect" doesn't tell us much.  It would be nice to know a bit more about the basics of how the Resonance NE radar works, especially with the Protivnik-GE since both were bought by Egypt and curious as to how they would be able to see the Israeli F-35s for example?

    I'm guessing that they're doing a lot of Intel with the Protivnik surveillance and watching for patterns and habits and developing a specific signature (since the distance is relatively close) and with the ability to IFF that they can create a library of signatures on all aircraft that are in the area and put them in their AWACs IFF information to recognize quicker who is out there etc.  But not sure how the Resonance NE does it's actual radar work?  Anyone?  

    People are obsessed with stealth because they have no physics education.   All materials that absorb must emit.   There are no black hole coatings.    And geometry does
    not work as people think it does.   Quantum mechanics means that classical optics are only an approximation.   So even an angled surface where classical optics would
    have no scatter back to the source will always have some percentage of photons scattering back at the source.    So modern Russian RADAR detectors can both discriminate
    very weak scatter signals and also measure them in different EM bands.   Using the meter band initial signal does not mean that the system only measures returning EM
    in the same EM band.   With RAM coatings it makes sense to have IR detectors.   And the trick is time-resolved Fourier analysis.   Out of the ambient IR coming from the
    atmosphere and the ground, the RAM re-emission of meter band EM emissions will stand out due to very tight temporal correlation between the radar beam and the
    signal.

    The resonance angle adopted is likely a way to amplify and simplify the processing of the scattered signal.   Here is one line of thought:

    https://ieeexplore.ieee.org/document/7447381

    All systems (e.g. F-35) will resonate at some frequencies.    This is not so trivial as not accounting for this properly can result in what happened to the Tacoma Narrows bridge.
    (Resonance is not limited to acoustic-vibrational aspects, it applies in the EM realm as well.) The RADAR pumps the target with enough frequencies to get more efficient return
    signal at some of them.  It looks like one meter EM is all that is needed and not some UWB beam solution.

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    GarryB
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    Post  GarryB on Sun Oct 04, 2020 5:16 am

    My understanding... which might not be right, is that the higher resolution radar can determine shape and feature details of a target... visible light is a high frequency, and allows us to see the shape of things when light is shone on the item to reflect to our eyes, but we can also improve our perception of something by using a flashing light like a strobe light, or a light of a particular colour.

    The amount of detail and processing power needed to make such eyesight useful means our eyes need to be located next to our brains and connected by a high speed wide band connection called the optic nerve.

    Because there is so much information you can actually fool a human being by rapidly displaying still images in order to give the impression of real world motion... 25 frames per second is sufficient for the human brain to think what they are seeing is something actually in motion like Wallace and Gromit which involves still images and bits of clay and plastic.

    An ordinary house fly have faceted eyes that are much more basic and detect movement and the bare necessities to fly around and find food, but it means when you try to hit them with your had they always manage to evade you... but try this... when you see a fly sitting on a flat table or wall take a swing to kill them... but the secret is not to slap them where they are on the table or wall... anticipate they will take off and fly about 10cm up off the table or away from the wall... cup your hand and swing it at the empty space above their position when you start the swing. Don't expect to track them... just swing for where they will be and you will find most of the time you get them.

    The point of the facets is not to improve the quality of their view, but to increase the field of view of their vision so they cannot be surprised... they take off quickly but are not super manouverable and wont be able to evade...

    Anyway, my understanding was that longer wave radar has physically longer energy beams that do not have high resolution, so with metre long or longer wavelengths an aircraft like an F-35 becomes a blob that reflects a radar signal of a blob and the redirection shaping and absorbing materials simply can't cope with such long wave beams so it just resonates the signal like a sound wave...

    Remember the blocky old low resolution images of Pluto that were taken before we had anything that got anywhere near it, so they were 10-15 pixels of colour showing no detail or features, but good enough to see it was there.

    Obviously that is using light so it is not the same, but even a black object can be seen during the day but is harder at night even with a light source.

    With long wave radar you provide the "light" source so there are no issues with not having enough light.

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    kvs
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    Post  kvs on Sun Oct 04, 2020 7:56 pm

    With RADAR visual reconstruction is not the priority. A prime reason for using the radar EM band is to see through condensed moisture like clouds and haze.
    As long as the target can be localized enough to have a missile take it out, that is mission accomplished. For resonance radar the important thing is
    wide EM band detection and processing of scattered and re-emitted signal plus any resonant harmonics it induces in the target. Using 1 meter EM
    scanning wavelengths is good enough.

    This is true because 1 meter is both a fraction and a characteristic scale of the target. So it can induce resonance effectively. Using a 1 km scanning
    beam wavelength would be great for penetrating mountain ranges without much scatter but would be low efficiency for detecting an object the size
    of an F-35. You do not need 500 micron EM for this job since shape details are not important.

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    Gomig-21
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    Post  Gomig-21 on Sun Oct 04, 2020 8:28 pm

    kvs wrote:With RADAR visual reconstruction is not the priority.   A prime reason for using the radar EM band is to see through condensed moisture like clouds and haze.
    As long as the target can be localized enough to have a missile take it out, that is mission accomplished.    For resonance radar the important thing is
    wide EM band detection and processing of scattered and re-emitted signal plus any resonant harmonics it induces in the target.   Using 1 meter EM
    scanning wavelengths is good enough.    

    This is true because 1 meter is both a fraction and a characteristic scale of the target.   So it can induce resonance effectively.   Using a 1 km scanning
    beam wavelength would be great for penetrating mountain ranges without much scatter but would be low efficiency for detecting an object the size
    of an F-35.   You do not need 500 micron EM for this job since shape details are not important.      

    That's really incredible and if this is essentially the way resonance works against stealthy aircraft, does it basically mean that all the shaping and RAM and IR reduction and all the American stealth innovation and application in the F-22 and the F-35 is moot at this point?! It's all for nothing or makes detection and tracking just a little bit more difficult than it would ordinarily be, if say, the objective was tracking an F-15 or MiG-29, for example?

    Conversely, why would Russia put all the effort into the Su-57 and the eventual PAK-DA and basically stealth aircraft then? Seems counterintuitive, so to speak. Sorry if I sound like a pain in the ass loool. I really don't mean to be, just really trying to learn about this entire system since someone comes out and says "hey, guess what, we just bought 2 types of Russian radars called the Protivnik-GE and the Resonance-NE of which the latter is capable of detecting stealthy targets like the F-35 at 600 kms!" Making such a claim just seems to need some effective validation/explanation and understanding because it's basically saying that all this $200 billion investment and development in stealth technology has essentially gone down the toilet with this radar technology!
    Begome
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    Post  Begome on Sun Oct 04, 2020 8:40 pm

    That's really incredible and if this is essentially the way resonance works against stealthy aircraft, does it basically mean that all the shaping and RAM and IR reduction and all the American stealth innovation and application in the F-22 and the F-35 is moot at this point?! It's all for nothing or makes detection and tracking just a little bit more difficult than it would ordinarily be, if say, the objective was tracking an F-15 or MiG-29, for example?

    Conversely, why would Russia put all the effort into the Su-57 and the eventual PAK-DA and basically stealth aircraft then? Seems counterintuitive, so to speak. Sorry if I sound like a pain in the ass loool. I really don't mean to be, just really trying to learn about this entire system since someone comes out and says "hey, guess what, we just bought 2 types of Russian radars called the Protivnik-GE and the Resonance-NE of which the latter is capable of detecting stealthy targets like the F-35 at 600 kms!" Making such a claim just seems to need some effective validation/explanation and understanding because it's basically saying that all this $200 billion investment and development in stealth technology has essentially gone down the toilet with this radar technology!
    I'm not as knowledgeable at physics as kvs but in my understanding a) Russia doesn't sacrifice that much with their stealth approaches, i.e. the Su-57 is a great aircraft even if you forget about the stealth features it has, which certainly cannot be said of the F-35, which has stealth as almost its only selling point (the other being avionics) and b) the kinds of radars making this possible are too big to put on aircraft so you still have a significant stealth advantage in areas where such sophisticated radars are not located on the ground, which is most of the world (for now) and they're probably rather easy to track by satellite (at least for major powers).

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    JohninMK
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    Post  JohninMK on Sun Oct 04, 2020 9:11 pm

    Begome wrote:
    I'm not as knowledgeable at physics as kvs but in my understanding a) Russia doesn't sacrifice that much with their stealth approaches, i.e. the Su-57 is a great aircraft even if you forget about the stealth features it has, which certainly cannot be said of the F-35, which has stealth as almost its only selling point (the other being avionics) and b) the kinds of radars making this possible are too big to put on aircraft so you still have a significant stealth advantage in areas where such sophisticated radars are not located on the ground, which is most of the world (for now) and they're probably rather easy to track by satellite (at least for major powers).

    It does make those ground radars one of the most important targets so how long they would last in a war must be problematic.
    Singular_Transform
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    Post  Singular_Transform on Sun Oct 04, 2020 9:40 pm

    JohninMK wrote:
    Begome wrote:
    I'm not as knowledgeable at physics as kvs but in my understanding a) Russia doesn't sacrifice that much with their stealth approaches, i.e. the Su-57 is a great aircraft even if you forget about the stealth features it has, which certainly cannot be said of the F-35, which has stealth as almost its only selling point (the other being avionics) and b) the kinds of radars making this possible are too big to put on aircraft so you still have a significant stealth advantage in areas where such sophisticated radars are not located on the ground, which is most of the world (for now) and they're probably rather easy to track by satellite (at least for major powers).

    It does make those ground radars one of the most important targets so how long they would last in a war must be problematic.

    It is very hard t find the long wave lenght early warning radars .


    Example all long wave radar operated during the Serb terror bombings, and no one of them was destroyed.

    Only the X band targeting radards can be found by triangulation .

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    marcellogo
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    Post  marcellogo on Sun Oct 04, 2020 11:51 pm

    Let's say that stealth was intended to counter specifically radar of X band i.e. the ones that allow to perform all functions from early detection to target tracking in the same frequence.
    With conventional radars operating in other frequencies is way less efficient, still it gave still a big advantage.

    With OTH, multistatic/passive and in future photonic radars you play another game with totally different rules and there is not any peculiar advantage in having stealth because they reverse the equation:instead of sending a light beam toward a black background trying to illuminate something inbetween the two, you are turning the background from black to white so than no matter if the object itself you are  searching is impervious to direct observation and look black, you would spot it the same.
    Out of the metaphor there still are differences: radar location is different from optical observation because it is not an immediate thing but gave you the informations you are looking for during an interval of time: so to get enough of them to shoot down an incoming stealth aircraft  would take a longer time than you would need for a non stealthy one.
    While a conventional radar observing a non stealthy object would pass between all different phases in a timely and smooth manner, such unconventional systems searching for a stealth ones would need more time to pass from early detention to effectively tracking it.

    Tactically however it would change very little as those system have all a quite great range so there is not such a great issue if they need a pair of minutes before giving you the information level you need to effectively being able to engage your intended target.

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    GarryB
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    Post  GarryB on Mon Oct 05, 2020 6:22 am

    That's really incredible and if this is essentially the way resonance works against stealthy aircraft, does it basically mean that all the shaping and RAM and IR reduction and all the American stealth innovation and application in the F-22 and the F-35 is moot at this point?

    To a degree yes, but Russia hasn't been doing nothing... these long wave and anti stealth radars didn't just fall from the sky... Russia has spent money and time and energy developing radars in different frequency ranges that can work together to help detect not just stealthy targets but also very small targets too.

    It is no accident that Soviet and Russia radar space tracking equipment could track chips of paint in orbit...

    It's all for nothing or makes detection and tracking just a little bit more difficult than it would ordinarily be, if say, the objective was tracking an F-15 or MiG-29, for example?

    Detection is critical... it doesn't matter what missiles and guns or decoys and EW equipment you have if you don't see the attack coming then it doesn't matter because it wont be used.

    Tracking is important to determine potential targets and what defence resources need to be alerted to deal with the problem.

    Even if you have radar sites that can detect stealth targets you need to get systems close to it to deal with it.... obviously even the dumbest 3rd gen fighter can be directed via ground based long wave radar to cannon range of a B-2 or F-117 to shoot them down.

    Directing that old fighter to an F-35 or F-22 would be more problematic for your old fighter...

    Conversely, why would Russia put all the effort into the Su-57 and the eventual PAK-DA and basically stealth aircraft then? Seems counterintuitive, so to speak.

    Think of it in terms of camouflage... right now the west has a few long wave radar stations that could track stealthy aircraft... if you take down such targets then they would struggle against stealthy targets because their general in service systems are not really optimised to deal with their own stealthy aircraft let alone Russian ones.

    US stealth is going for near invisible and so it is enormously expensive to buy and to maintain.

    Russian stealth is not to be invisible but be harder to see and engage... a much lower bar that is much cheaper but still effective enough to be tricky to deal with and they are not going for an all stealth fighter fleet... the new MiG light 5th gen fighter and Su-57 are not going to replace all their existing types... they are going to have a mix of options.

    With bombers the PAK DA is going to be flying wing stealthy, but likely not as super stealthy as the B-2 because its primary role is not bomber... it is stand off cruise missile carrier... odds are it will never fly anywhere near US territory and its hypersonic 10,000km range missiles will penetrate western air defences... they just wont see where it came from... with new nuclear powered cruise missiles with unlimited range the PAK DA might take off and fly 5,000km away from its target before launching its missiles...

    The Su-57 will be stealthy so it is not interrupted as it hunts down F-35s and F-22s... its wing mounted long wave AESA radars used to triangulate the location of stealthy targets...

    Making such a claim just seems to need some effective validation/explanation and understanding because it's basically saying that all this $200 billion investment and development in stealth technology has essentially gone down the toilet with this radar technology!

    If only it was that cheap... the F-35 programme alone is 1.5 trillion... plus F-117 and F-22 and B-2 and B-21... and the secret programmes and Commanche and the stealthy weapons and drones...

    It does make those ground radars one of the most important targets so how long they would last in a war must be problematic.

    Most of them are mobile and in service in large numbers... and the issue of finding them... very long wave signals are very hard to locate or jam.

    Conversely very short wavelengths are hard to jam too... for instance radar guided hellfire missiles, or the MMW radar systems used by APS systems on tanks are hard to detect at distance and also hard to target with missiles too.

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    kvs
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    Post  kvs on Tue Oct 06, 2020 6:08 pm

    The size of the resonance radar is limited by the size of the detectors of the return signal. From what I can tell, phased arrays can do this
    job "almost" independent of size. So with a combination of high sensitivity (i.e. signal to noise discrimination) phased array elements and
    compact computer processing package a resonance radar can be installed on a fighter jet. Ground stations will always have the advantage
    of not having to compromise for size (much) so custom antennas for the needed wavelengths can be used which have better gain. But
    phased arrays are far from useless.

    The lists of disadvantages of phased arrays typically hovers over economics and aspects that are not all that important for war. Phased
    arrays can process multiple bands simultaneously and can process incoming EM from a wide range of angles without needing any movement.

    These days computer processing power is more than enough to control phased arrays and do instant Fourier analysis on the return
    signal. So there is no obstacle to mounting "anti-stealth" radars on jets.



    Isos
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    Post  Isos on Tue Oct 06, 2020 6:14 pm

    Today everyone has the same electronics and T/R technology. Even a country like Turkey has it.

    What will make a radar better than the other is the math formulas used and the alghoritm.

    Russians and french have quite good mathematicians. US universities are full of chinese. Chinese spend more time copying and from what I saw on twitter from SAA their radars sucks a lot.

    US have money and can start many projects at once. Their civilian companies also attract best foreign engineers and their idea are taken for military stuff.
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    Post  Singular_Transform on Tue Oct 06, 2020 9:33 pm

    Isos wrote:Today everyone has the same electronics and T/R technology. Even a country like Turkey has it.

    What will make a radar better than the other is the math formulas used and the alghoritm.

    Russians and french have quite good mathematicians. US universities are full of chinese. Chinese spend more time copying and from what I saw on twitter from SAA their radars sucks a lot.

    US have money and can start many projects at once. Their civilian companies also attract best foreign engineers and their idea are taken for military stuff.

    The quality /size /power of radar gives the performance of it.

    The alogrithm will imporve it, but if th radar manufactured with too high tolerances then the performance of it will be degraded.
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    Post  LMFS on Wed Oct 14, 2020 10:54 pm

    Nebo-M to be deployed in the Volga region:

    https://iz.ru/1073816/anton-lavrov-roman-kretcul/kupol-neba-povolzhe-i-ural-zashchitiat-radarami-rekordsmenami

    The article has some interesting details and comments by Murakhovsky

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    Gomig-21
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    Post  Gomig-21 on Tue Oct 20, 2020 1:37 am

    GarryB wrote:Anyway, my understanding was that longer wave radar has physically longer energy beams that do not have high resolution, so with metre long or longer wavelengths an aircraft like an F-35 becomes a blob that reflects a radar signal of a blob and the redirection shaping and absorbing materials simply can't cope with such long wave beams so it just resonates the signal like a sound wave...

    If this is an accurate explanation, then I can safely say that this is the one that I understood the most! You know why? Because you dumbed it down for me! lol That's what I needed.

    I read and re-read KVS' post over and over maybe a dozen times but just couldn't grasp it. Same with the other posts but I certainly appreciate the effort that everyone who chose to answer my question made. Thank you for taking the time to answer.

    So essentially, resonance means longer wavelengths that are a meter long and by being that long, they tend to overwhelm the subject they're bouncing off and that subject's stealthy attributes can only cope with such long wavelengths that scattering it or redirecting it by shaping or absorbing it via its RAM for only so much until an actual and identifiable return does come back which is discernable? Am I getting it right in an even more super dumbed down version, or not?
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    Post  LMFS on Tue Oct 20, 2020 2:03 am

    Gomig-21 wrote:So essentially, resonance means longer wavelengths that are a meter long and by being that long, they tend to overwhelm the subject they're bouncing off and that subject's stealthy attributes can only cope with such long wavelengths that scattering it or redirecting it by shaping or absorbing it via its RAM for only so much until an actual and identifiable return does come back which is discernable?  Am I getting it right in an even more super dumbed down version, or not?

    The problem with physics is either you know it or not, there are few shortcuts or intuitive analogies that work all of the time, and this is specially relevant with EM fields, which are seriously complicated and, especially for the magnetic field, counter-intuitive.

    That being said, the wavelength can be seen as the size of the pencil when making a drawing. If the thickness of your pen is bigger than the size of the details you try to draw, they will not be recognisable. So, a stealth plane whose details are in the centimeter-decimeter range can not be "represented" by a wavelength in the meter range. The plane will not be able to reflect the incoming EM field in a structured way and so it will not be able to scatter it away from the emitting radar.
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    Post  GarryB on Tue Oct 20, 2020 4:45 am

    Think of it in terms of quality of signal... a very high frequency means more content and detail... like an AM radio signal is mono sound... even with headphones you get two copies of one sound signal. With higher frequency... FM... the sound quality can be improved and two sound channels sent, so you get more detail, but shorter range and you need a good aerial to get a better signal.

    Human vision is excellent or can be.

    Paint and material camouflage is effective because we see so well.

    If we could only see in a small range of colours and could mainly see movement like most animals then camouflage would be much less effective.

    You could paint yourself up to match the background perfectly but if I was looking at you in IR with a thermal imager which sees heat instead of visible light then you would glow like anything else the same temperature.

    Stealth uses shaping to direct light away from its source... the opposite to the reflector on a bike or car that directs light back at a light... so when your headlights shine on a bicycle the reflector actually looks like a light in its own right when it does not have batteries and just reflects the light your lights directed at it.

    A stealth "reflector" would redirect the light you were shining at the bike away from the lights so it would look black and hard to see.

    Imagine a man standing in the middle of a field at night holding a full length mirror. It is completely dark. If he holds the mirror between you and him with the mirror facing you directly when you shine your torch at him you will see the light reflected directly back at you so you will see yourself and your torch so he will be easy to see. If he turns the mirror 45 degrees, you would no longer see yourself or your torch... you would see whatever is 90 degrees from his position which might be a light or it might be black... if he angles the mirror up the your torchlight will go up into the sky, but if he angles the mirror down you might see your torchlight on the grass leading away from him which might give you an indication of where he is.

    The use of enormous power is like trying to light up the whole field and spotting the black spot where light is not coming back to you.

    His problem is that if you start changing frequencies then it has different properties... I have mentioned IR and the EM spectrum is enormous... a mirror is optimised to redirect visible light, but it does not work as a mirror to sound or radio waves...


    When you look at an aircraft you can see it... no matter what shape it is...

    But to see the detail in an aircraft you need it to be well lit as well.

    With very high frequency radar it uses a lot of energy to show lots of detail... including shape.

    Long wave radar doesn't have that level of detail on that scale... radar waves a few mms long can show detail down to half their wavelength, but that is the same for all waves... so an AM radio signal that is a kilometre long is just going to bounce off an object a dozen metres wide... it will appear as a blob and not a shaped object... but it will be a radar reflection from somewhere where there is no reflection or a very weak reflection in very high frequencies...

    An aircraft like an Su-57 with an L band radar and IRST and Ku and Ka band high frequencies should quickly be able to establish the positions of objects that appear out to max range in L band but are very weak in Ku and Ka bands, and have IR signatures...


    The problem with physics is either you know it or not, there are few shortcuts or intuitive analogies that work all of the time, and this is specially relevant with EM fields, which are seriously complicated and, especially for the magnetic field, counter-intuitive.

    Nice way of saying blind leading the blind I think.... Twisted Evil

    Analogies can only be taken so far and sometimes are mistaken for fact.

    A good example is the fabric of spacetime... someone used the analogy that space time is like a fabric, but now we know space is expanding... but when you expand fabric eventually it rips or tears... but that is fabric... not space time. For all we know space time is not a fabric but has been described as a fabric so normal people can better understand what these people are talking about... but that does not mean space time could ever rip or come apart... we really have no idea.

    One of the best descriptions of stealth I have seen was a comparison between the cockpit canopies of the Hughes 500 helicopter (bubble canopy) and the Mi-28s tiny flat transparencies.

    Imagine both helicopters hovering 100m in front of you and the sun is behind you shining brightly.

    With the Hughes 500 there will be a shiny bright reflection of the sun in the bubble canopy so no matter what the helicopter does it will be easily visible just by this bright reflection.

    The Mi-28 however has tiny flat canopy windows so most of the time the sun will not be visible but as it turns and climbs and flys around occasionally you will get a bright flash when the sunlight is reflected to your position... most of the time the sun will not be visible at all.

    Neither aircraft is actually stealthy of course but if they were the transparencies would be angled to almost never reflect the light or radar back to an observer, and the reflecting surfaces will be minimised as much as possible... like optical ports in a tank.
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    Post  kvs on Tue Oct 20, 2020 5:59 am

    Even though 1 meter radar cannot scatter useful information from a 1 cm object like micrometer band waves, it will still scatter something since we
    are dealing with photons and quantum mechanics. One could scan a 1 cm object with a 1 m wavelength beam if the angles and intensity could
    be varied. Having more than one source of the scanning beam also helps a lot. This way you get additional information that can be used to
    construct an image of the target. This assumes no resonance in the target.

    But this is usually not practical under rapidly changing conditions such as movement of the target and the resources that can be deployed
    to engage in this process are limited. Resonance radars are nifty because there will be harmonics induced by a 1 m wavelength beam
    that are of shorter and longer wavelengths. In fact, they do not depend on the radar scanning beam details too much as long as we
    are not talking much longer incoming wavelengths which rapidly weakens the amplitude of resonance harmonics and thus makes them
    harder to detect. So the job of resonance radars is to detect wavelengths expected to be generated in aircraft like objects.

    Modern radars really do undermine the effectiveness of stealth. The monochrome radars of the 1950s are ancient history.

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    Post  Gomig-21 on Wed Oct 21, 2020 7:27 pm

    kvs wrote:Even though 1 meter radar cannot scatter useful information from a 1 cm object like micrometer band waves, it will still scatter something since we
    are dealing with photons and quantum mechanics.    One could scan a 1 cm object with a 1 m wavelength beam if the angles and intensity could
    be varied.   Having more than one source of the scanning beam also helps a lot.   This way you get additional information that can be used to
    construct an image of the target.   This assumes no resonance in the target.

    But this is usually not practical under rapidly changing conditions such as movement of the target and the resources that can be deployed
    to engage in this process are limited.   Resonance radars are nifty because there will be harmonics induced by a 1 m wavelength beam
    that are of shorter and longer wavelengths.   In fact, they do not depend on the radar scanning beam details too much as long as we
    are not talking much longer incoming wavelengths which rapidly weakens the amplitude of resonance harmonics and thus makes them
    harder to detect.    So the job of resonance radars is to detect wavelengths expected to be generated in aircraft like objects.  

    Modern radars really do undermine the effectiveness of stealth.   The monochrome radars of the 1950s are ancient history.
     

    So what you're basically saying is that Resonance radars send long, 1 meter wavelengths that also (by default?) create/induce harmonics within those wave lengths once they're bouncing off the target, and those harmonics create varied RETURN waves that are long and short which give more information on the target instead of returning only longer wavelengths since those really don't contain much detail by themselves.  Does that pretty much summarize it correctly in a really layman way, or is it an incorrect deduction of your post?
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    Post  kvs on Wed Oct 21, 2020 10:05 pm

    Gomig-21 wrote:
    kvs wrote:Even though 1 meter radar cannot scatter useful information from a 1 cm object like micrometer band waves, it will still scatter something since we
    are dealing with photons and quantum mechanics.    One could scan a 1 cm object with a 1 m wavelength beam if the angles and intensity could
    be varied.   Having more than one source of the scanning beam also helps a lot.   This way you get additional information that can be used to
    construct an image of the target.   This assumes no resonance in the target.

    But this is usually not practical under rapidly changing conditions such as movement of the target and the resources that can be deployed
    to engage in this process are limited.   Resonance radars are nifty because there will be harmonics induced by a 1 m wavelength beam
    that are of shorter and longer wavelengths.   In fact, they do not depend on the radar scanning beam details too much as long as we
    are not talking much longer incoming wavelengths which rapidly weakens the amplitude of resonance harmonics and thus makes them
    harder to detect.    So the job of resonance radars is to detect wavelengths expected to be generated in aircraft like objects.  

    Modern radars really do undermine the effectiveness of stealth.   The monochrome radars of the 1950s are ancient history.
     

    So what you're basically saying is that Resonance radars send long, 1 meter wavelengths that also (by default?) create/induce harmonics within those wave lengths once they're bouncing off the target, and those harmonics create varied RETURN waves that are long and short which give more information on the target instead of returning only longer wavelengths since those really don't contain much detail by themselves.  Does that pretty much summarize it correctly in a really layman way, or is it an incorrect deduction of your post?

    Just as materials can resonate at certain vibrational frequencies (e.g. Tacoma Narrows bridge incident), they can also vibrate in the
    EM realm as well. All materials absorb since there are no perfect reflectors (and absorbers outside of black holes if they exist). One
    meter radar EM waves will go through materials including metal. The Faraday cage effect from electrostatics applies to some extent
    but since scanning waves are not some steady state illumination and include a magnetic component they will penetrate the skin of the aircraft
    (with attenuation due to absorption and scatter). Even the skin of the aircraft is a source of resonance harmonics and it does not have to
    be just the frame, the engines or other "volume filling" objects.

    So think of the targeted aircraft as absorbing the 1 meter radar waves and then emitting a broad spectrum of waves with both shorter
    and longer wavelengths compared to the scanning radar beam. Being resonance harmonics, they do not form a continuous spectrum
    of emissions but are organized in spikes depending on the characteristics of the aircraft. So different aircraft will give different spectra
    of resonance emissions but likely not wildly different. So the return signal that the radar system needs to process is not 1 meter original
    wavelength scanning beam scatter, but new wavelengths likely to form from resonance in the aircraft body. This requires testing
    with targets to figure out what bands to detect for resonance return signal.

    A detail that should be mentioned is that the amplitude of the scanning beam can be cranked up to produce a better return signal.
    No amount of RAM coating will save you from this. And no RAM coating works 100%. In fact, since RAM is an absorber it must be
    an emitter (in some other wavelengths). So the aircraft will still be exposed to EM waves induced by the original radar scanning beam
    and will produce harmonics in some other bands compared to what the radar beam itself would directly induce. Regardless, cranking
    up the scanning beam amplitude returns a "cornucopia" of resonance EM emissions that one could detect if one looked for them.

    By contrast, using passive IR emissions does not allow you do dial the return signal since the source of those IR emissions is independent
    of the radar (no longer radar really) system. Also, IR is scattered and blocked by clouds and fogs more effectively than radar and
    at least some of the resonance harmonics.

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    Post  Gomig-21 on Thu Oct 22, 2020 5:52 pm

    kvs wrote:Just as materials can resonate at certain vibrational frequencies (e.g. Tacoma Narrows bridge incident), they can also vibrate in the
    EM realm as well.   All materials absorb since there are no perfect reflectors (and absorbers outside of black holes if they exist).   One
    meter radar EM waves will go through materials including metal.   The Faraday cage effect from electrostatics applies to some extent
    but since scanning waves are not some steady state illumination and include a magnetic component they will penetrate the skin of the aircraft
    (with attenuation due to absorption and scatter).   Even the skin of the aircraft is a source of resonance harmonics and it does not have to
    be just the frame, the engines or other "volume filling" objects.  

    So think of the targeted aircraft as absorbing the 1 meter radar waves and then emitting a broad spectrum of waves with both shorter
    and longer wavelengths compared to the scanning radar beam.  Being resonance harmonics, they do not form a continuous spectrum
    of emissions but are organized in spikes depending on the characteristics of the aircraft.   So different aircraft will give different spectra
    of resonance emissions but likely not wildly different.    So the return signal that the radar system needs to process is not 1 meter original
    wavelength scanning beam scatter, but new wavelengths likely to form from resonance in the aircraft body.   This requires testing
    with targets to figure out what bands to detect for resonance return signal.  

    A detail that should be mentioned is that the amplitude of the scanning beam can be cranked up to produce a better return signal.
    No amount of RAM coating will save you from this.   And no RAM coating works 100%.   In fact, since RAM is an absorber it must be
    an emitter (in some other wavelengths).   So the aircraft will still be exposed to EM waves induced by the original radar scanning beam
    and will produce harmonics in some other bands compared to what the radar beam itself would directly induce.    Regardless, cranking
    up the scanning beam amplitude returns a "cornucopia" of resonance EM emissions that one could detect if one looked for them.

    By contrast, using passive IR emissions does not allow you do dial the return signal since the source of those IR emissions is independent
    of the radar (no longer radar really) system.   Also, IR is scattered and blocked by clouds and fogs more effectively than radar and
    at least some of the resonance harmonics.

    Thank you for taking the time to post that and to answer all my pain in the ass questions! lol.  You and Garry and the other fellas have been great and I'm very appreciative at the patience and information you've outlined.  I'm starting to understand how this resonance radar works against stealthy aircraft and why country X has bought it along with the Protivnik-GE since I'm guessing the surveillance part of the latter radar works well with the Resonance-NE and in tandem will aid in developing a signature library, so to speak.  That goes with what you said in this particular section of your post, I think:

    So think of the targeted aircraft as absorbing the 1 meter radar waves and then emitting a broad spectrum of waves with both shorter
    and longer wavelengths compared to the scanning radar beam. Being resonance harmonics, they do not form a continuous spectrum
    of emissions but are organized in spikes depending on the characteristics of the aircraft. So different aircraft will give different spectra
    of resonance emissions but likely not wildly different. So the return signal that the radar system needs to process is not 1 meter original
    wavelength scanning beam scatter, but new wavelengths likely to form from resonance in the aircraft body. This requires testing
    with targets to figure out what bands to detect for resonance return signal.


    Based on that bolded part, it sounds like once they set up these radars, they actually need to test them for a while against these stealthy targets to develop those recognizable return wavelengths and then be able to organize that collected info into a library of sorts so that when the day comes and they're looking at the radar return signals in a time of war, they'll have these signatures already predetermined so that the instant the radar pics up a stealthy aircraft, it's recognized immediately.  In other words, without all this testing and gathering of information and the creation of a recognizable library, you couldn't just field a brand new resonance radar and expect it to instantly give you recognizable, stealthy targets right off the flick of the switch.  You need to first create an organized compilation of information that is preset from all that testing in order to recognize it when the crap hits the fan, so to speak? lol.
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    Post  GarryB on Fri Oct 23, 2020 3:47 am

    If you watch the combat approved series of videos there was one particular episode where there were a whole lot of different scale models shown of different aircraft and missiles and things and they were raised up by a cable system to be held up in the air with various radar and equipment around the place. The cable they were suspended from allowed the models to be rotated in various axis so you could scan it with a radar and rotate it in real time to view the model with the radar from every possible direction.

    This sort of thing creates a radar image in that frequency from that radar antenna for that target type... and they could do the same in optical and IR so they can store a 3D database of what objects look like in HF radar and IIR frequencies and use computer processing power to match this library of images from every potential angle with radar returns in the real world to rapidly identify a target and label it correctly within the system.

    The Americans did something similar to develop stealthy designs... they just made shapes they guessed would work best... made models and hung them up in front of real radars and tested the results. Eventually thanks to a paper by a Soviet scientist they were able to create a mathematical model of how radar waves work in the real world and were then able to use computers to test thousands of shapes at a time and pick perhaps the best 5 or 10 to make and test in their testing facilities.

    If they did what the Russians are doing now they likely would have realised the Iranian F-14 diving at them in Iranian waters in the 80s was actually a climbing Airbus... but if they can't tell something is climbing and then levelling off, and are convinced it was diving and accelerating... then no amount of computer help would matter I guess.

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    Post  Gomig-21 on Fri Oct 23, 2020 8:20 pm

    GarryB wrote:If you watch the combat approved series of videos there was one particular episode where there were a whole lot of different scale models shown of different aircraft and missiles and things and they were raised up by a cable system to be held up in the air with various radar and equipment around the place. The cable they were suspended from allowed the models to be rotated in various axis  so you could scan it with a radar and rotate it in real time to view the model with the radar from every possible direction.

    This sort of thing creates a radar image in that frequency from that radar antenna for that target type... and they could do the same in optical and IR so they can store a 3D database of what objects look like in HF radar and IIR frequencies and use computer processing power to match this library of images from every potential angle with radar returns in the real world to rapidly identify a target and label it correctly within the system.

    The Americans did something similar to develop stealthy designs... they just made shapes they guessed would work best... made models and hung them up in front of real radars and tested the results. Eventually thanks to a paper by a Soviet scientist they were able to create a mathematical model of how radar waves work in the real world and were then able to use computers to test thousands of shapes at a time and pick perhaps the best 5 or 10 to make and test in their testing facilities.

    If they did what the Russians are doing now they likely would have realised the Iranian F-14 diving at them in Iranian waters in the 80s was actually a climbing Airbus... but if they can't tell something is climbing and then levelling off, and are convinced it was diving and accelerating... then no amount of computer help would matter I guess.

    That's great. I do enjoy those episodes of Combat Approved but it might be tough finding that one particular show. I'll try and look for it.

    Sounds like all that SIGINT and ELINT work with radars and creating stored signatures that are instantly identifiable is true in this case with radars. It makes sense that would be the way it's done since it's not really expected that you pull up to a hill, put the parking brake on, raise the radar and associated equipment and power everything up and you're ready to pick up F-35s flying 600 km away! There's a lot more that goes into it to develop the system that eventually makes it work a bit easier in time of war.
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    Post  chinggis on Fri Oct 23, 2020 10:12 pm

    If you try to understand how radar work and some of physics, try to make TDR(Time Domain Reflectometer). You can find schematics on internet, and it is not expensive at all, I made my TDR for my job(I need them for looking where is fault in telecommunication cables), in time when I do not have any job I play with TDR and use it like a simple radar. Of course it is primitive version like a radars from early 1940 but it is working. In TDR you can change pulse width, what is pulse width shorter more details you get but range is short. Longer pulse width you can see fault on longer distance. My TDR is working with 9V battery and it have power of 15mW, in theory I can see u p to 10-14 km(with longer pulse width) in reality 8-10km. But in shorter pulse width I can see fault with more details but cost is 100meters.

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    Post  Gomig-21 on Sat Oct 24, 2020 2:48 am

    Hole wrote:Russian Radar systems - Page 22 000424
    New radars

    This is really something else.  So I see the obvious 2 systems in Algeria and Egypt and the one(s) in Russia, but any idea what the 4 are that seem to be coming out of Iran?
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    Post  kvs on Sat Oct 24, 2020 8:12 am

    The testing of potential targets for resonance radar systems is necessary but not the end of the story. With modern computing
    power combined with wide spectrum detection it is possible to have real time adaptive detection. Since the target will emit EM
    in some form regardless, any new signals (not part of natural emissions) on the horizon can be "tuned" and followed. The key
    is the ability of the detection arrays, especially the phase-array components, to catch new signals.

    In some ways it is easier to cover more of the EM spectrum than to have models built on tests only. The tests are useful for
    giving information about generic resonant emissions of various structures. So that helps to focus on certain regions of the
    EM spectrum and devote more detection resources to them.

    Any flying object will be producing emissions that are not part of the normal atmospheric and ground emissions. But these
    signals may be weak enough to be missed if the focus of the radar system is too narrow. The 1950s radars are the definition
    of narrow focus since they detected the backscatter of the scanning beam. This made stealth worthwhile. In the 1960s
    and against 3rd world countries that later. But physics gives solutions to defeat stealth and it is a matter of development
    and investment to achieve this.

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