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    Su-57 Stealth Fighter: News #6

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    tanino

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    Post  tanino on Fri Sep 25, 2020 8:35 am

    Thank you all for your answers and analysis.

    I have to make interactive HTML5 infographic SPOTs (for new militar power publications) and I'm thinking about the basic concepts.

    Therefore, the 360 degree average value counts more, which depends on many external factors (distance, height, radar band, etc. etc.).
    Stealthflanker
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    Post  Stealthflanker on Fri Sep 25, 2020 9:54 am

    LMFS wrote:
    I don't think you can establish some kind of monotonic relationship between frequency and RCS... at all. There are resonance effects, and there are structures designed for destructive interference at certain wavelengths, those are highly non linear effects... maybe you can clarify further?

    Su-57 Stealth Fighter: News #6 - Page 17 RayMieOpt

    Yeah for sphere while in reality different shapes follows kind of its own relationship. Cylinder in other hand have different relationship

    Su-57 Stealth Fighter: News #6 - Page 17 Cylind10


    Things full of wedge like aircrafts have wavelength dependency while Ballistic missile warhead or missiles have follows square of wavelength.
    You can browse papers in IEEE mainly by Kuschel regarding VHF frequency and research that being done in Europe for it.  You'll find this illustration :

    Su-57 Stealth Fighter: News #6 - Page 17 Wavele10

    and this is another from "Air and Spaceborne Radar an introduction" by Lacomme. Depicting RCS dependence on Frequency.

    Su-57 Stealth Fighter: News #6 - Page 17 Relati10

    The rules of thumb of the frequency dependence as the last graphs depicted will fall at extremely low frequency, this is mainly the dimension of the target is much-much smaller compared to the wavelength and thus no longer exhibit any resonance.

    Now for some practical overview. This is a model of a stealth plane that i made

    Su-57 Stealth Fighter: News #6 - Page 17 22540175_10210050338039313_8817427765108072413_n.jpg?_nc_cat=110&_nc_sid=8024bb&_nc_ohc=exr4NRfVCcIAX-r_Zx6&_nc_ht=scontent-xsp1-1

    It's basically tacit blue but with V tail.  and this is the frontal aspect RCS vs Frequency

    Su-57 Stealth Fighter: News #6 - Page 17 22549587_10210050339599352_3249359881813517081_n.jpg?_nc_cat=109&_nc_sid=8024bb&_nc_ohc=YPLW6G1CR-EAX-LtA9w&_nc_ht=scontent-xsp1-1

    As you can see there is kind of strong trend of increase of RCS as the wavelength increased.

    Another shape however like this KFX model that i made, shows rather weak but still visible wavelength dependency of its RCS.

    Su-57 Stealth Fighter: News #6 - Page 17 C-107-model-by-stealthflanker-dbmmy29-5ab27ce0dcad5b2ad1202a23

    The RCS vs Frequency.
    Su-57 Stealth Fighter: News #6 - Page 17 21317470_10209762770890314_563775613645302814_n.jpg?_nc_cat=106&_nc_sid=8024bb&_nc_ohc=zRg46T8pod8AX_R35NJ&_nc_ht=scontent-xsp1-2

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    Post  GarryB on Fri Sep 25, 2020 1:56 pm

    ESM is passive, as is the operation of EO/IR sensors. Data links are now highly directional.

    Russian borders are covered by radars that are not passive but are also well defended. Being an IADS some S-400s could have some or all of their radars operating while other platforms in the network listen with their radars turned on but no emitting... it is a game both sides play.

    AWACS is and will be always some hundreds of km behind the combat planes it is controlling,

    That is OK... on full AB a MiG-31 can cover 700km in about 14 minutes and then launch long range active radar homing missiles with a range of 300km at the moment. The fact that they are working with India on new scramjet powered anti AWACS missiles suggests that this is only going to get worse for the AWACS platform over time.

    that is why it has a huge very powerful radar with huge field of view and extremely long range.

    Which makes it a huge and obvious target for those looking for it...


    BTW I am not making this a "who is stronger" contest, just making it clear that in principle there are ways to keep surveillance of the battlefield and that very far SAM shots give enemy fighters some critical time to defend themselves. All the rest of this discussion has gone very far from the original claim.

    Well based on the news about the AA Brahmos, it could be that the MiG-31s will focus on bombers and ships and the Su-57 with a 2,000km range mach 10 scramjet powered anti AWACS missile might take over its duties.

    I would think plans to evolve the R-37M with small missiles that deploy when the missile approaches its target could be applied to a much larger scramjet powered missile too...

    If there is no external guidance or tactical information and the plane's ESM detects enemy radar emission focused on itself, it is not very wise to keep its own radar off is it? This is like the surface combatant with radars off... one would think going to war would be enough adrenaline already, without needing to do that.

    But S-400s will fly very high and as an approaching target the size of a dinner plate by the time it becomes visible to the fighters radar it might be too high up in its line of vision to be detected... in which case the target aircraft might only realise it is under attack when it is 20km away diving at mach 5 or mach 6... and assuming a 150kg directional warhead and the missile finding the target in the centre of its dive view I would say my money would be on the missile most of the time...

    Aerial targets are a matter of AWACS, ground troops are monitored by JSTARS, as far as I know.

    During Desert Storm the Americans boasted their AWACS could see lines of barbed wire in the sand in the lines of defence... so it does follow ground targets too AFAIK.


    He is creating a whole story around made up figures, so off they go both, the figures and the story...

    Without any figures there is nothing to discuss... if you don't like his figures give us yours and we can continue with those... if we can accept those as plausable... don't need sources... just a bit of reasoning will do.

    Exactly the reason why making wild guesses does not bring anything. Estimations can be done, but they need to be backed by data and proper calculations / reasoning. I can say I "think" the detection range of the Su-57 is 50 km, you "think" it is 250... who cares what we think?

    Without numbers then theories and hypothesis is pointless. It gives us a frame work to work up tactics and suggestions.

    So the detection range is?

    The fins make 90º angle with the body of the missile, that reflects radar rather effectively.

    They tend to roll so no fin will be 90 degrees for very long if at all. Also.... what are the fins made out of... they might be radar transparent for all we know...

    Detection range will be poor because these will not be bigger than 1 sq metre targets, and will roll over to present its nose to the targets it is heading for...

    It is just a 20 m tall fireball, who would notice it?

    The battery could be located behind a low row of hills and might not be visible at all till the missile has climbed quite a bit... besides... is it an S-400 or a Smerch rocket?

    Point two, I was not dealing with AWACS vs SAM scenario, I was just saying properly supported fighters will normally be able to stay away from very far SAM shots... I find it rather surprising that this claim can be so controversial, actually.

    Even if they are tracked with pin point accuracy how is a fighter plane supposed to evade a mach 7 400km range missile exactly?

    I mean a last second roll might gain a few metres...

    Syria obviously has proved that the hundreds of rigorously made RCS models of VLO aircraft executed in the most renowed Federation's Institutes was perfectly right while PR figures was .....exactly that: low level disinformation and propaganda boasting.

    Funny they refused to let Turkey operate S-400 and F-35 in the same airspace.... that would have proved their propaganda boasting to be correct... or maybe it might have revealed something they didn't want to be revealed until they had delivered more...

    Cost/effectivness of stealth is become shittier every year. Limited and controled stealth is still a good point for new fighter but it will be useless one day or another.

    I think the lesson is that Stealth can be important but don't spend trillions trying to make something invisible... when if comes to soldiers you hand out ghillie suits to snipers who sneak around and rely on not being seen or noticed but for the average infantryman a ghillie suit would be cumbersome and awkward and wouldn't make them harder to spot most of the time.

    The US put all their eggs in one basket and went for expensive all out stealth. The Russians didn't have that sort of dough to throw away but they still made a stealth fighter, but with more emphasis on fighter than on stealth and they also equipped their fighters with radars able to find stealthy aircraft in the L band and also fitted all their new fighters with IRST systems and IR guided missiles... and made the manouverable enough to be able to dogfight even with they run out of missiles...

    It was a war 60ies/70ies technology against state of the art western technolgy...unfair conflict! And stealth technology at this time had a few advantages, but many many problems too. The problems with stealth technology haven't changed until today.


    Observations of how HATO fought in that war and other wars before and since have led to the creation of air defence systems like Pine and Pantsir and TOR and BUK and S-350 etc etc.

    Are the Western models so bad?

    Western models are likely fine, it is their marketing department that choose what figures are released...

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    LMFS
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    Post  LMFS on Fri Sep 25, 2020 3:38 pm

    Stealthflanker wrote:The rules of thumb of the frequency dependence as the last graphs depicted will fall at extremely low frequency, this is mainly the dimension of the target is much-much smaller compared to the wavelength and thus no longer exhibit any resonance.

    Now for some practical overview. This is a model of a stealth plane that i made

    Very interesting research. I think it is more or less clear to see that simple shapes can have a dependence, while complex ones are more difficult to predict and if RAM/RAS are added or the selective behaviour of radiofrequency apertures is considered, then I think it is simply too complex and non linear. But if you are just looking for very rough approximations and not considering RAM or other complexities maybe you can be onto something.

    GarryB wrote:That is OK... on full AB a MiG-31 can cover 700km in about 14 minutes and then launch long range active radar homing missiles with a range of 300km at the moment. The fact that they are working with India on new scramjet powered anti AWACS missiles suggests that this is only going to get worse for the AWACS platform over time.

    I definitely would not like to be in a NATO AWACS close to the Russian front in case of a war, that is for sure...

    As to the anti-AWACS Brahmos, it is just a ramjet unless I missed a big one... such high-value planes will end up including (many) self defence missiles, it is the only practical way (unless DEW get massively better than they are now) of keeping them alive more than 20 minutes in the battlefield. The fact that the missile is launched by the target itself simplifies greatly the interception and partially offsets the great advantage ground-based assets would otherwise have in terms of firepower. That would force them to have more ready to launch SAMs or make them more complex (multi-warheads as discussed previously) and so place a bigger burden on the defending side.

    But S-400s will fly very high and as an approaching target the size of a dinner plate

    Wow that must be a big plate Razz

    If I have the time I will try to find some information about possible detection distance of such a missile by means of airborne radars, but I doubt it will happen in the short term. Until then it is not possible to reach a conclusion IMHO, unless you provide that info.

    Without any figures there is nothing to discuss... if you don't like his figures give us yours and we can continue with those... if we can accept those as plausable... don't need sources... just a bit of reasoning will do.

    If you don't have official figures you are not automatically entitled to making them up. If you get rough ones through estimations and assumptions, you explain them and see whether they are acceptable to your counterpart. Nobody is forced to accept estimations and the ensuing conclusions without a solid reasoning supporting them in the first place.

    is it an S-400 or a Smerch rocket?

    Is this flare very stealthy in your opinion? S-400 missiles are quite bigger than Smerch rockets.

    Su-57 Stealth Fighter: News #6 - Page 17 S400-1

    Even if they are tracked with pin point accuracy how is a fighter plane supposed to evade a mach 7 400km range missile exactly?

    I mean a last second roll might gain a few metres...

    Remember, I am talking about long range shots. It is very obvious to understand that no-scape zone for a heavy, slow target like bombers, tankers or ISR aircraft is much bigger than that against fighters right? As explained before, against a short range shot not even a fighter will have time to react and try to change direction, whereas against a far shot such a target, assuming it is aware of the attack, can perform defensive manoeuvring. Do you want that we make some numbers and see how much remains of those theoretical 400 km range against a fast and agile target like a fighter?

    Western models are likely fine, it is their marketing department that choose what figures are released...

    Other theoretical studies that I have seen are broadly compatible with -30 dBsm frontal RCS. Manufacturers' claims go even further but in principle their designs would be VLO according to those papers. Let us keep in mind that the study linked above is not considering RAM.

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    Stealthflanker
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    Post  Stealthflanker on Fri Sep 25, 2020 5:19 pm

    LMFS wrote:

    Very interesting research. I think it is more or less clear to see that simple shapes can have a dependence, while complex ones are more difficult to predict and if RAM/RAS are added or the selective behaviour of radiofrequency apertures is considered, then I think it is simply too complex and non linear. But if you are just looking for very rough approximations and not considering RAM or other complexities maybe you can be onto something.



    That rules of thumb in fact is used in radar frequency selection. as in following paper.

    https://id.scribd.com/document/406074780/Volume-Surveillance-Radar-Frequency-Selection

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    Post  Mindstorm on Fri Sep 25, 2020 9:03 pm

    LMFS wrote:What is the difference then? Are the Western models so bad? I mean, they can certainly check them against real measurements, and in fact Ufimtsev ended up working in the US.

    The level of mathematical scattering field computation models is not the point; US know perfectly the REAL effective scattering area of theirs low observable aircraft exactly like it know perfectly the REAL engagement range of theirs air to air missiles or air to ground PGM but that obviously do not prevent USA operatives from purposely inflate at times those parameters, in perfect line with theirs established tradition of disinformation, to force the enemies to overspend in wastefull countermeasures.

    That disinformation posture worked true wonders in the R. Reagan era with the immense amount of boasted idiocies the US managed to invent literally from thin air with the façade programs named SDI and since then all US operatives must contribute to those disinformation efforts in all theirs public declarations: it is free for them but, if trusted, can cause enormous economical and time damages to the enemies.

    USAF and allies Air Forces operatives obviously must actively contribute to that systematic ,doctrinal disinformation effort ,the examples can be found anywhere and several ones today can even cause some laughters (because real interaction with the aircraft have proved how much ridicule those declarations was) ,but at the times even some domestic designers and ,above all some generals, had the doubt that those declared capabilities was real - the ultimate aim of this well established US practice -.

    At example at the beginning of the trials of F-22 at Red Flag ,year 2007, the RAAF Squadron Leader Stephen Chappell said a simlar idiocy

    "The thing (F-22 ,personal note) denies your ability to put a weapons system on it, even when I can see it through the canopy,"

    https://www.jble.af.mil/News/Article-Display/Article/259981/raptor-debuts-at-red-flag-dominates-skies/

    Obviously when the proof of reality come in the way of the ridiculous fairy tales declarations coming from Red Flag happened that neither EF-2000, neither Rafale, neither our Су-35C pilots recently ever experienced any problem in locking any weapon of theirs choice with any type of guidance on an F-22 and much ,much before having the possibility to see it through the canopy; but at the time it was all a concert of the incredible level of stealth of the F-22 preventing even at those reduced range to acquire a fire solution on it Razz Razz Razz

    This is the military version of the ridiculous idiocies of the two Skripals and lately Navalny supposedly poisoned with the ,by very far, the most powerful nerve agent ever conceived and all after a short while being well and happy......western propaganda is truly conceived for totally brainless sheeps both in the military field that outside it .

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    Post  LMFS on Sat Sep 26, 2020 12:54 am

    @Mindstorm:

    your take that it is all basically a farce has certainly more than a bit of truth to it, it is perfectly in line with the "in your face" lying attitude of the US and accordingly the level of investment of the Western military, industry and public on the stealth myth is truly gigantic. Since RCS cannot be calculated easily in a realistic way and true values can be protected as a matter of national security, it is an ideal issue where reality can be largely exaggerated. My purely personal opinion is that the levels of RCS achieved by them are certainly tactically relevant, I find it very difficult that every study is falsified to reflect results "relatively" compatible with US MIC claims, but as you pointed out with the study you linked, looking in bigger detail some questions arise. Even a generous use of RAM would not get frontal RCS below -15/-20 dBsm for the higher part of the X band in that case, which is still very advantageous but nowhere near the miracle values we hear frequently. Interestingly, the authors of that study try indeed to play along established truths and state the compatibility of their results with claimed values, even when at some points there is a gap of more than 40 dB that cannot be bridged by RAM. We have also seen how discording voices (like that of Carlo Kopp or Pierre Sprey re. F-35) are marginalized via media lynching, it is very likely that authors of strongly diverging results would think twice before publishing them.

    @stealthflanker:

    Thanks for the link, do you know how they justify the assumption they make in regards of RCS dependence with frequency? The say it variates with 1/f^2 below 1 GHz and stays constant above that value, which we know is not quite real and is also different to your formula. What kind of targets do they try to model? Maybe this two regimes are related with the different scattering regimes applied to the kind of shape and size they consider their model target, it may even be a simplification of the sphere model in the Optical and Mie regions.

    I still consider that VLO designs that are purposely designed to defeat certain frequencies are probably not realistically modelled via a general formula with monotonic functions. The approach can be used as a way to get a lower bound of the RCS though, since the radar defeating mechanisms normally operate better at higher frequencies. New designs optimized to defeat low frequency radars (new flying wing layouts) may change that, though...
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    Post  GarryB on Sat Sep 26, 2020 8:30 am

    I definitely would not like to be in a NATO AWACS close to the Russian front in case of a war, that is for sure...

    Me neither, but the enemy are not idiots, so no matter what super weapon you create now... in ten years time they will develop things and weapons to counter them, or tactics to render them useless...

    It is the nature of the game.

    As to the anti-AWACS Brahmos, it is just a ramjet unless I missed a big one... such high-value planes will end up including (many) self defence missiles, it is the only practical way (unless DEW get massively better than they are now) of keeping them alive more than 20 minutes in the battlefield.

    Well that is the thing... all these ramjet and scramjet powered weapons are going to lead to DEW and other solutions which can be applied to all sorts of situations... measure countermeasure et al.

    The fact that the missile is launched by the target itself simplifies greatly the interception and partially offsets the great advantage ground-based assets would otherwise have in terms of firepower. That would force them to have more ready to launch SAMs or make them more complex (multi-warheads as discussed previously) and so place a bigger burden on the defending side.

    If the self defence missiles the AWACS aircraft uses are not huge long range high power missiles then the obvious solution for the attacking side is dozens of small missiles in a bundle in the nose mounted warhead area that releases at 80km altitude 50km short of the target which fan out and then converge on the target in a steep diving attack at high speed...

    Russia is already working on self defence missiles for fighters and bombers for stealthy internal carriage... 9M100...

    Wow that must be a big plate

    I can get hungry...

    If I have the time I will try to find some information about possible detection distance of such a missile by means of airborne radars, but I doubt it will happen in the short term. Until then it is not possible to reach a conclusion IMHO, unless you provide that info.

    It would be important to take into account of the look up angles of the radars in question....

    If you don't have official figures you are not automatically entitled to making them up. If you get rough ones through estimations and assumptions, you explain them and see whether they are acceptable to your counterpart. Nobody is forced to accept estimations and the ensuing conclusions without a solid reasoning supporting them in the first place.

    There are not going to be official figures, so the next best thing is to make them up... some conservative and some optimistic... work out what the situation would be in each case would give a better understanding of the effect of stealth too.... is it worth spending trillions to get as good a level as you possibly can, or set more realistic goals and make it affordable and attainable.

    I remember discussing the new Russian Stealth fighter in the 1990s with most in the west saying Russia hasn't got the production capacity to make plane shapes to the precision necessary to achieve stealth and wont have for the next 50 years. The same people said by now the Russian aviation and space industry would be bust and the Russian AF would be flying handmedowns F-16s that HATO countries had passed on out of pity after they moved to F-35s and Typhoons.

    Is this flare very stealthy in your opinion? S-400 missiles are quite bigger than Smerch rockets.

    But what does it look like from 400km away?

    Remember, I am talking about long range shots. It is very obvious to understand that no-scape zone for a heavy, slow target like bombers, tankers or ISR aircraft is much bigger than that against fighters right?

    Yes, I understand, but if I was in London flying around in a plane and a massive bright flare of light appeared below me I would know I was in trouble... but a massive bright flash of light in Paris I probably wouldn't notice... as it climbs it will roll over in the direction it is headed... I am not going to know which direction it is rolling either... if it comes towards me and somehow ground control spot the missile are they going to put out a warning to everything in the air that a big missile is coming but they are not sure which target it is going after?

    When it scans it will scan all the targets in its field of view so getting painted briefly by the S-400 system just means you are one of the 200 odd targets it is tracking... you really don't know if you are under attack until the missile illuminates you... which I would argue is then too late...

    Do you want that we make some numbers and see how much remains of those theoretical 400 km range against a fast and agile target like a fighter?

    If you are the only one in the air then radical changes in direction or heading or speed might help, but I am not totally convinced.... for an air to air missile flying at you that is changing direction all the time it would work, but for very long range missiles you can do all sorts of manouvers that wont matter because it will always just be getting closer to you... it is like a car missile trying to hit a car in a different city... the target car can move around all it likes but the car on the way essentially just has to get to the target city before starting to worry about actually tracking down the target car and running in to it.... unless the target car actually leaves the city and drives to another city further away and actually out of range, moving around in the city wont make much difference because it is not targeting you directly yet anyway.

    That disinformation posture worked true wonders in the R. Reagan era with the immense amount of boasted idiocies the US managed to invent literally from thin air with the façade programs named SDI and since then all US operatives must contribute to those disinformation efforts in all theirs public declarations: it is free for them but, if trusted, can cause enormous economical and time damages to the enemies.

    It also runs the risk that the enemy might develop counter technologies that actually work and can be applied to existing problems that were otherwise no solvable with existing technologies...

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    Post  Stealthflanker on Sat Sep 26, 2020 9:43 am

    LMFS wrote:
    @stealthflanker:

    Thanks for the link, do you know how they justify the assumption they make in regards of RCS dependence with frequency? The say it variates with 1/f^2 below 1 GHz and stays constant above that value, which we know is not quite real and is also different to your formula. What kind of targets do they try to model? Maybe this two regimes are related with the different scattering regimes applied to the kind of shape and size they consider their model target, it may even be a simplification of the sphere model in the Optical and Mie regions.

    What i use is also simplification of the 3 scattering regime. If you read the Brazillian paper provided by Mindstorm back then you will found the deriviation of the 1/F^2 formula and how it relates to the squared wavelength that i use. They will end up the same.

    The justification is that in optical regime, frequency have little effect in RCS thus why it is assumed to be constant while frequency lower than L-band have wavelength usually bigger than typical target features e.g LE slats etc which essentially resonant (MIE) scattering regime where frequency starts to have bigger says on RCS and the trend would be upward until the point is reached where the wavelength become so much bigger that no longer resonance effect can happen.



    I still consider that VLO designs that are purposely designed to defeat certain frequencies are probably not realistically modelled via a general formula with monotonic functions. The approach can be used as a way to get a lower bound of the RCS though, since the radar defeating mechanisms normally operate better at higher frequencies. New designs optimized to defeat low frequency radars (new flying wing layouts) may change that, though...

    They dont. But in my view who have to work to calculate the range it is very essential as it give rapid, scientifically sound and based plus useful relationship which close to reality. Instead of having to rely on some vague value which may not include frequency or more information regarding it (e.g path propagation factor).

    Desire to get the most accurate result is unfruitful and frustrating mainly because :
    1.Secrecy as nobody wants to actually tells you the real value
    2.It goes beyond what typical people can do as "dynamic RCS" or so requires far more computationaly intensive software or expensive ITAR Controlled software such as CADRCS and RadBase While most people may only have access to commercial CSD Microwave Studio, POFACETS. College students may have FEKO But this requires cluster computer as it use MOM (Methods of Moments).
    3.Nobody can agree yet on what to define. All discussions must be based on sound and agreeable basis. But as we see in typical RCS related discussion, people cant even agree what value to use and in what condition.



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    Post  LMFS on Sat Sep 26, 2020 7:26 pm

    GarryB wrote:If the self defence missiles the AWACS aircraft uses are not huge long range high power missiles then the obvious solution for the attacking side is dozens of small missiles in a bundle in the nose mounted warhead area that releases at 80km altitude 50km short of the target which fan out and then converge on the target in a steep diving attack at high speed...

    Since they just need to prevent the attacking missile from hitting the plane, they can be as short range as you want, even guided rounds would do. There are enough technologies now for autonomous guidance and therefore serious increase in the interception capacity, even against multiple simultaneous attacks.

    I can get hungry...

    Sure, that is more than half a meter in diameter Razz

    It would be important to take into account of the look up angles of the radars in question....

    AESA in scan mode has typically a beam deflection of 60º in azimut and elevation, that is a substantial FOV even against high-flying targets.

    There are not going to be official figures, so the next best thing is to make them up... some conservative and some optimistic... work out what the situation would be in each case would give a better understanding of the effect of stealth too.... is it worth spending trillions to get as good a level as you possibly can, or set more realistic goals and make it affordable and attainable.

    Well, let's say that there are estimations I am more than happy to entertain and others not so much... you can read above stealthflanker's work for some serious approach I will always welcome, agreeing or not. He will not get 100% perfect results but he surely can explain the method he used. No offence intended against any one, but you cannot expect people with some technical background to accept any kind of methodology...

    But what does it look like from 400km away?

    It depends, are there space based assets? Surveillance UAVs? Enemy fighters with EO systems in the surroundings? What are the meteorological conditions?

    If you are the only one in the air then radical changes in direction or heading or speed might help, but I am not totally convinced.... for an air to air missile flying at you that is changing direction all the time it would work, but for very long range missiles you can do all sorts of manouvers that wont matter because it will always just be getting closer to you... it is like a car missile trying to hit a car in a different city... the target car can move around all it likes but the car on the way essentially just has to get to the target city before starting to worry about actually tracking down the target car and running in to it.... unless the target car actually leaves the city and drives to another city further away and actually out of range, moving around in the city wont make much difference because it is not targeting you directly yet anyway.

    First, the bearing of the missile will be in the direction of the target, that is a good hint even in case there was not a clear radar lock. Besides, before launching a missile there needs to be some IFF interrogation wouldn't you agree?

    What is clear is that aircraft threatened by a missile are not going to wait until it hits them to find out whether they were the targets. They will pull out of its engagement range. That means, targets fast and agile enough may enter the area under threat but with options to exit in time, slower targets will not even enter that area.

    stealthflanker wrote:What i use is also simplification of the 3 scattering regime. If you read the Brazillian paper provided by Mindstorm back then you will found the deriviation of the 1/F^2 formula and how it relates to the squared wavelength that i use. They will end up the same.

    I will do, I did not have the time for an in-depth read until now.

    The justification is that in optical regime, frequency have little effect in RCS thus why it is assumed to be constant while frequency lower than L-band have wavelength usually bigger than typical target features e.g LE slats etc which essentially resonant (MIE) scattering regime where frequency starts to have bigger says on RCS and the trend would be upward until the point is reached where the wavelength become so much bigger that no longer resonance effect can happen.

    What is the lower limit of frequency / max target size / target shape considered for your approximation?

    They dont. But in my view who have to work to calculate the range it is very essential as it give rapid, scientifically sound and based plus useful relationship which close to reality. Instead of having to rely on some vague value which may not include frequency or more information regarding it (e.g path propagation factor).

    Desire to get the most accurate result is unfruitful and frustrating mainly because :
    1.Secrecy as nobody wants to actually tells you the real value
    2.It goes beyond what typical people can do as "dynamic RCS" or so requires far more computationaly intensive software or expensive ITAR Controlled software such as CADRCS and RadBase While most people may only have access to commercial CSD Microwave Studio, POFACETS. College students may have FEKO But this requires cluster computer as it use MOM (Methods of Moments).
    3.Nobody can agree yet on what to define. All discussions must be based on sound and agreeable basis. But as we see in typical RCS related discussion, people cant even agree what value to use and in what condition.

    Fair enough, that is really well explained and researched... I agree you are not going to get anything better easily. The intention deserves being commended, even when I am sceptic because VLO targets include strong non-linear behaviours as mentioned above. How do you think that approximation works with frequency selective RAM or apertures?
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    Post  limb on Sun Sep 27, 2020 5:10 pm

    Has anyone here heard of carbon nanotube RAM? The US claim that they massively reduce RCS against L-Band and VHF radars and have allegedly installed them on the F-35. If this is legit, L-band and OTH radars could be rendered useless or much less effective at detecting stealth aircraft at long ranges
    https://www.youtube.com/watch?v=XHmETdirunE&t=610s
    I know binkov is a half informed retard, but he is only source I have heard the claim(starting at 8:46) about carbon nanotube RAM. He also reports that the russians and chinese have also experimented with carbon nanotube RAM. if this is true, then this technology is legit because not only the US has invested into it. The question is how much of a lead, if any the US has with it and if it has installed it on the F-35s.

    It would be really appreciated if mindstorm had any info regarding the physical and material science possibilities of fielding this technology, and if russia fields it too? ARe the americans lying that carbon nanotubes can reduce RCS?
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    Post  Isos on Sun Sep 27, 2020 5:19 pm

    Russian radars spotted f-35 in Iraq from Russian mainland when Iran attacked US bases there.

    They need to put more of those nanotubes IMO lol1 .

    Carbon nanotubes are well known by everyone.
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    Post  GarryB on Mon Sep 28, 2020 7:53 am

    Perhaps rather than carbon their tubes are made of grass, because it sounds like they are grasping at straws.

    The irony is that if they are correct and RAM made of such materials is that effective then you could apply it to any existing aircraft rendering normal aircraft stealthy and making the concept of the expensive F-35 irrelevant...

    Russia is one of the biggest exporters of carbon nano tubes, so when the Americans claim the T-34 to be an American tank design because it used suspension distantly related to a Christie design, then I guess the Soviets can claim the SR-71 and F-35 are Soviet and Russian aircraft because they mostly use Soviet and Russian titanium parts, and now all stealth aircraft in the world will use Russian nanotubes... hahahaha...

    And for those that don't recognise it I am be sarcastic... sadly the few who cling to the belief that the Soviets can only copy are not joking...
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    Post  limb on Tue Sep 29, 2020 6:54 am

    Is it true that carbon nanotube layers can absorb L-band radar?
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    Post  tanino on Tue Sep 29, 2020 10:34 am

    Thank you all for the great ideas. I will update you on the work.

    F-35: If it were true what they say (hidden detection much better than a Su-57 (20 km vs. 90 km) etc. etc.), it would be true.

    Then I do not understand:

    why in Israel, which for 20 years has dominated with air superiority, knowing the quality of their pilots and how they know how to handle technology...

    Yet they have the F-35.

    Strange.

    Then these new media attacks against Su-57.

    The management of (probable/true or fake, or only demonstrators) of their prototype of sixth generation. Without photo. Without giving support (for example to Boeing if it were partner (in full crisis 737 Max).

    Strange.

    And after having surely analyzed the photos of the 50002 RAM coverage.

    More and more strange.
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    Post  GarryB on Tue Sep 29, 2020 12:05 pm

    Is it true that carbon nanotube layers can absorb L-band radar?

    If it were true then why mention it?

    Russia makes carbon nanotubes too and if they haven't noticed yet why tell them?

    So they can have cheap stealth as well?

    why in Israel, which for 20 years has dominated with air superiority, knowing the quality of their pilots and how they know how to handle technology...

    Yet they have the F-35.

    Saying the F-35 must be good if the Israelis buy and use it, but if the F-35 is so good why do they never enter Syria airspace when they launch standoff attacks from the mountains of neighbouring countries?

    If F-35 is superior and stealthy why is the US so afraid of Turkey operating F-35s and S-400s in the same airspace... I mean Israeli F-35s near Syria should already be operating in the same area that Russian radars are operating in... and if they want to deploy F-35s to HATO forces how are they going to do that and avoid Russian S-400s ever being near them?

    The management of (probable/true or fake, or only demonstrators) of their prototype of sixth generation. Without photo. Without giving support (for example to Boeing if it were partner (in full crisis 737 Max).

    Putting the F-15 back into production will not be cheap so it is an obvious admission that the US 5th gen Fighters have failed to deliver...

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    Post  Isos on Tue Sep 29, 2020 12:24 pm

    Putting the F-15 back into production will not be cheap so it is an obvious admission that the US 5th gen Fighters have failed to deliver...

    That's the reason they buy f-15 again. It is expensive but f-22 would be 4 or 5 times more expensive to start again just like its exploitation price would be huge and would have a big impact on it perfs/disponibility.

    Having 10 nice jets is still better than 1 super jets.

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    Post  LMFS on Wed Sep 30, 2020 1:50 am

    Details about the production line of the Su-57 at KnAAZ:

    https://zen.yandex.ru/media/id/5ddfbc8b9515ee00ac9e370a/tehperevoorujenie-s-importozamesceniem-5f71cca9fde6297ce39fbf7e

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    Post  GarryB on Wed Sep 30, 2020 11:36 am

    Having 10 nice jets is still better than 1 super jets.

    Most of the time it is not the aircraft themselves that make the difference but all the force multipliers that operate with them that make them too difficult to effectively counter.

    They could simply put most of the avionics and systems of the F-22 into the new upgraded F-15s... it wont make them stealthy or anything but that means they can be cheaper and carry more weapons.

    Looking at Israeli use of F-35s in Syria... an F-16 could probably carry a lot more munitions further and faster and much much cheaper... the only reason they use F-35s is likely PR in the US... which makes sense because it is probably US taxpayers that are subsidising their purchase anyway... they probably pay full price but it is included in military aid to the Jewish state, so it probably doesn't actually cost them anything.
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    Post  tanino on Thu Oct 01, 2020 8:53 am

    LMFS wrote:Details about the production line of the Su-57 at KnAAZ:

    https://zen.yandex.ru/media/id/5ddfbc8b9515ee00ac9e370a/tehperevoorujenie-s-importozamesceniem-5f71cca9fde6297ce39fbf7e


    Thank you! I think it's one of the reasons for the overall clear quality improvement (-dBm). Let's wait to see the 00002 finished. And maybe with some high resolution photos.


    I make a consideration:
    at the end of the 90's there were no high resolution shots or photos (in general, I mean then published on the web). So many of the photos we have always seen of the 5 generation aircrafts existing then, it was surely more difficult to see defects or inaccuracies (or see quality).

    All details that were immediately discussed and analyzed for the T-50...

    This also contributed.
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    Post  GarryB on Fri Oct 02, 2020 10:43 am

    Another factor is that before stealth fit and finish were an extra cost.

    For early model MiG-29s the outer skin of the aircraft was just the outer skin... it really didn't matter if there was a 2mm gap between sheets or a 5mm gap... the airflow over the surface is turbulent anyway so it didn't effect flight performance in any way.

    For current model MiG-29s the skin of the aircraft is the outer skin of the sealed internal compartments... for many of which they act as fuel tanks so having complete seals is actually important, so if you compare photos of old and brand new the difference would be enormous... but that is not to say the old aircraft were bad... it would just add weight to have added fuel tanks and the spaces they could use to hold fuel were much more limited so its fuel fraction was lower... but it was also much cheaper and easier to make.

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    Post  Hole on Sat Oct 03, 2020 11:32 am

    Su-57 Stealth Fighter: News #6 - Page 17 Xagwgv10
    Su-57 Stealth Fighter: News #6 - Page 17 Yurzhi10
    Su-57 Stealth Fighter: News #6 - Page 17 Aa-5710

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    Post  JohninMK on Sat Oct 03, 2020 12:35 pm

    Photos better at link https://twitter.com/spriter99880/status/1312170309722595328

    Su-57 Stealth Fighter: News #6 - Page 17 EjXD2SnWkAELpFB?format=jpg&name=360x360

    Su-57 Stealth Fighter: News #6 - Page 17 EjXD4EcWkAYbIfS?format=jpg&name=360x360

    Su-57 Stealth Fighter: News #6 - Page 17 EjXD6IoXcAkQ1yX?format=jpg&name=360x360

    Su-57 Stealth Fighter: News #6 - Page 17 EjXD09ZWoAE0m66?format=jpg&name=360x360

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    Post  Isos on Sat Oct 03, 2020 3:32 pm

    Su-57 Stealth Fighter: News #6 - Page 17 Ejzilg10
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    Post  Isos on Sat Oct 03, 2020 3:37 pm

    In your icture they are talking about izd 750, izd 760 and izd 170-1 and izd 160 missiles/weapons. Any idea what it could be ?

    The last ones should be r-77M and r-37M or r74 and it says only 2 per weapon bay not 6 as some said here before.

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