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    Is Russia safe from F-22 and Β-2?

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    hoom

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    Re: Is Russia safe from F-22 and Β-2?

    Post  hoom on Sun Feb 26, 2017 6:29 am

    A Tu-22 sized aircraft would have no strategic value.
    Yeah I meant to imply something between Tu-160 (267t) & Tu-22 (124t), say 150-170ton loaded weight so similar or a bit bigger than B1B/B2.
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    GarryB

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    Re: Is Russia safe from F-22 and Β-2?

    Post  GarryB on Sun Feb 26, 2017 8:34 am

    It will be based on the Tu-160s basic shape and if that wing tunnel model above is an indication it may have a body like section extending back from the centre wing area making it potentially heavier than the blackjack.

    Obviously not something they could do to the blackjack to increase payload or range because area rule means it needs a narrow body section.

    With a subsonic design however you can have an extended rear section acting as a lifting body so it does not add too much to the RCS or drag.

    That would maximise space for larger internal weapon and fuel capacity... those new long range cruise missiles and hypersonic cruise missiles will not be small weapons... it would also add the possibility of an anti ship model able to perhaps carry 12 Zircon hypersonic anti ship missiles for example.

    A subsonic model will be much lower cost than the Blackjack... like the Bear in fact... so using it in a scenario like Syria to deliver a dumb bomb load of 20 odd tons or more over theatre ranges of perhaps 3-4 thousand kms would be a useful role for the aircraft in addition to its strategic nuclear role.

    For such a role high altitude operations would make it rather safer than stealth so it would not carry a full payload or a full load of fuel for such an operation to maximise its operating altitude and get a reasonable speed performance.

    Azi

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Azi on Sun Feb 26, 2017 9:19 am

    Singular_Transform wrote:
    You mixing up two distinct things.
    .
    .
    .
    The Serbian operators DETECTED the F-117 and B-2 aircrafts, but they never managed to TARGET them with the X band radars.
    I mixed nothing up! It is clear that detection and targeting are two pair of shoes.

    But it should be clear that a B-2 will not be visible at max. detection range of Nebo VHF or a OTH radar. I gave a example...B-2 has in short wave a RCS of 0,0001 estimated by murican fanboys and realistic of 0,001 sqm. In VHF area it is estimated 100 times larger, so 0,1 sqm, means a detection range of 170 km and that's pretty good. Painting and targeting is something different and not so easy at 170 km. And of course it is pure soothsaying, but based on some data and that's more than just saying stealth is shit!

    By the way...
    It is possible to paint a stealth aircraft with short wave radar and shot it down. Serbian AD did it in 1999! Magic words are datalink, sensitivity of receiver, good data processing and energy of painting sender (ok, not used by serbian AD Laughing ).

    But the discussion is about this...
    GarryB wrote:
    Azi wrote:LOOOOL! So you guys wanna tell me that the B-2 has a greater RCS in VHF than a Tu-95!?


    Actually that would be logical...


    Singular_Transform wrote:Occam's razor : if coating can make something "stealth" then no one needs complicated and expensive shaping, all the stealth technology needs is a spray can and a monkey to spray it onto the air-plane.

    The stealth idea and technology 40 years old. And there is no magic paint.

    long electromagnetic wave will be scattered from the edges, and no paint can help this, only if it is extremely thick.
    You should remember that they are 3 techniques to make a object stealth:

    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    - Second is to use RAM coating. RAM "absorbs" radar through interference (thickness) or excitation on molecular level, for example like water absorbing microwaves. In long wave range some RAM are loosing near all of their ability, some other retain more. There is a large selection of RAM based on different physic characteristics.

    - Third is geometry of object!

    Normally no technique in itself is good enough to make a aircraft really stealth, so the techniques must be combined. Of course stealth features are weaker in long wave radar, but we can't generalize and say EVERY stealth aircraft loose complete stealth ability in VHF area. We must pick up aircraft after aircraft and analyse it and we will see that F-22 and F-35 loose nearly all stealth characteristics in VHF and B-2 retain some stealth ability in long wave radar.

    About this I was writing and answer was "not to jerk off too much". lol!


    Last edited by Azi on Sun Feb 26, 2017 12:27 pm; edited 2 times in total (Reason for editing : grammar)

    Azi

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Azi on Sun Feb 26, 2017 10:07 am

    kvs wrote:People should read up on phased arrays.  Phased array systems can target track ICBM warheads thousands of miles away.  
    I can't believe that this discussion raised the "radar" wavelength as being under some major constraint from targeting limitations.
    The whole purpose of a phased array is to remove this limitation.

    The GaN amplifiers allow extreme signal discrimination.   So that extremely weak signals can be received and processed.  
    They allow the "radar" wavelength to be extended well into the regime where everything that is flying can be easily tracked.
    No matter what type of RAM coating and shaping is used.
    No! Long wave radar in HF and VHF spectra can only see if something is there, they lack complete accuracy for targeting at long distance. If two aircraft are flying near together you can't distinguish the two from each other at long distance, both would be one signal. By the way, this was the method how Russia was sending nearly undetected aircraft to Syria in 2015. In the "shadow" of normal support flights. NATzO and USA was complete surprised seeing at satellite image dozens of russian aircraft.

    You are right that you reach a better detection with phased array, data processing and so on, but the problem is still the wavelength. If you are using wavelength around 1 m you can't be precise in the same area. For example it's impossible to see atoms or electrons with EM in visible light spectra, even with the best microscope in the world.

    Targeting takes place in short wave area. For example the AN/TPY-2 of US THAAD system works in X-Band with a range of 1000 km and high accuracy. Here a link to russian engagement and fire control radar

    You are right with the point that all data can be combined and processed to reach a greater detection and engagement range. That's right, but the specifications are secret and we simply don't know what will be detection and engagement range against specific stealth aircraft. In the end we will know it in a conflict, but no one want a conflict so it's better to keep that secret, than to reveal it in a hot conflict.
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    Militarov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Militarov on Sun Feb 26, 2017 12:49 pm

    Singular_Transform wrote:
    Militarov wrote:

    We lost basically 80% of our Neva launchers and every single fixed radar site that wasnt disassembled and moved elsewhere to storage. We lost few Kubs too but those spent more time on the move than actually being combat ready and thats why they survived. Two Dvina batteries we tried to reassemble were destroyed too halfway though preparations.

    So its far from being true that we "remained intact", that is just load of BS. Stop claiming things that have no connection with reality whatsoever.

    When its about our command chain, are you aware that we shot down own MiG-29? You know why? Because we had untrained bunch of baboons manning majority of our equipment and organisation like African tribes. Units that survived, survived either due to their nature or fact that certain officer in chain of command was not braindead. Generally speaking, those that actually did good job were mostly low ranking officers that commanded batteries.

    You also need to know that our officers, many of them, took huge advantage of wartime, stealing military equipment, computers, radios... all kinds of supplies. Trust me... 1999. was not any kind of success.

    I presume you are a half empty guy : )

    Lets call it being realistic.

    Mindstorm

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Mindstorm on Sun Feb 26, 2017 2:51 pm

    Militarov wrote:We lost basically 80% of our Neva launchers and every single fixed radar site that wasnt disassembled and moved elsewhere to storage.


    Interesting, and where come from those data ?

    Surely not even from NATO sources Laughing

    Not even in the theirs initial damage assessment finding - December 1999 - (subsequently significantly revised down for the results of MEAT direct finding on the field) a similar figure was ever claimed.

    In fact also in that first assessment, where the initial figure of 11 out of 16 С-125 was claimed to have being put out of service by NATO Air Forces in the course of the entire campaign, the "event" was related to elimination of the battery's radars ,sustaining "severe to lethal" damages, not the much harder to engage launchers.  

    Let me guess : that secret thruth, that not even the same initial NATO's assessment had ever had the courage to claim, has been confided by your legendary " AD commanding officiers" .....

    Reality, as always, is much more simple : NATO air campaign was obvioulsy highly effective in destroy and degrade Serbian economic, civil and production infrastructures (up to unstustainable level for the political leadership) while failing shockingly to inflict any relevant damage to the overall military structure, in spite the crushing difference in the realitive force's size and age of their systems.

    NATO's Air Forces employed its most up-to-date sytems (some of which still in validation phase), such as AGM-130, B-2 bomber, ALE-50 decoy, JDAM and so on, against at best end of '60 years AD technology, but in spite of that, as explained previously, what those Air Forces exploited was simple ,usual, old  kinematical and reaction times limits of those antediluvian SAM systems.

    When ,for the effect of personal initiative of the operatives,  a single, totally insulated, Serbian AD battery (equiped with the same antediluvian systems) managed to partially blur those limits the effect on the relative exchange ratio against those overwhelming forces was instantly subverted.
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    Singular_Transform

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Singular_Transform on Sun Feb 26, 2017 11:11 pm

    Militarov wrote:

    Lets call it being realistic.

    So, what you think, compared to say US AD operators , is your capability and training on par with them or inferior ?
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    Singular_Transform

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Singular_Transform on Sun Feb 26, 2017 11:35 pm

    Azi wrote:


    By the way...
    It is possible to paint a stealth aircraft with short wave radar and shot it down. Serbian AD did it in 1999! Magic words are datalink, sensitivity of receiver, good data processing and energy of painting sender (ok, not used by serbian AD Laughing ).

    ?
    so, what is the target ?

    To make it hard to detect OR to make it hard to shoot down?




    Azi wrote:
    You should remember that they are 3 techniques to make a object stealth:

    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    - Second is to use RAM coating. RAM "absorbs" radar through interference (thickness) or excitation on molecular level, for example like water absorbing microwaves. In long wave range some RAM are loosing near all of their ability, some other retain more. There is a large selection of RAM based on different physic characteristics.

    - Third is geometry of object!

    Normally no technique in itself is good enough to make a aircraft really stealth, so the techniques must be combined. Of course stealth features are weaker in long wave radar, but we can't generalize and say EVERY stealth aircraft loose complete stealth ability in VHF area. We must pick up aircraft after aircraft and analyse it and we will see that F-22 and F-35 loose nearly all stealth characteristics in VHF and B-2 retain some stealth ability in long wave radar.

    About this I was writing and answer was "not to jerk off too much". lol!


    Ok, it is getting interesting : )

    There are radar transparent materials, example every aircraft contain lot of air , and that is transparent for radar. And completly irrelevant .



    The thickness of the coating is quite thin, due to weight restrictions, means the effect of the coating is magnitude smaller than


    the most important feature, the shaping.

    Quite much like the gamma radiation protection on the spacecrafts.
    Exist, but practicaly useless.good for calibration.

    So, you can play with the coating, but that won't change too much about the signature.

    And the shaping has smaller and smaller effects as the size vs wavelenght getting closer to 1:1, and at that level it become irrelevant.

    The resolution of a radar array depeding on the number of emiters.

    So, the NEBO-M resolution is only 1/6 of the F-35 radar, and the smallest details are half meter bit, not few mm big as with the AN/APG-81,


    But thanks for the scattering still possible to identify other aircrafts.


    The 170 km for the NEBO-M is the minimum deistance.
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    Singular_Transform

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Singular_Transform on Sun Feb 26, 2017 11:39 pm

    Azi wrote:
    No! Long wave radar in HF and VHF spectra can only see if something is there, they lack complete accuracy for targeting at long distance. If two aircraft are flying near together you can't distinguish the two from each other at long distance, both would be one signal. By the way, this was the method how Russia was sending nearly undetected aircraft to Syria in 2015. In the "shadow" of normal support flights. NATzO and USA was complete surprised seeing at satellite image dozens of russian aircraft.

    You are right that you reach a better detection with phased array, data processing and so on, but the problem is still the wavelength. If you are using wavelength around 1 m you can't be precise in the same area. For example it's impossible to see atoms or electrons with EM in visible light spectra, even with the best microscope in the world.

    Targeting takes place in short wave area. For example the AN/TPY-2 of US THAAD system works in X-Band with a range of 1000 km and high accuracy. Here a link to russian engagement and fire control radar

    1m wavelenght decrease the angular information, but the scattering increase the frequency information.

    The X band radards collecting fata from the angular infromation, and from the dopler shift, the VHF from the frequency infromation, and from the dopler shift.

    Exapmle, the two aircrafts identification will require similar methods like sorting out diferent materials from a visual spectral of a glowing object.

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    GarryB

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    Re: Is Russia safe from F-22 and Β-2?

    Post  GarryB on Mon Feb 27, 2017 1:17 am

    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    Point one counters point three.

    There is no point in spending billions of dollars on designing and manufacturing an aircraft to a fraction of a mm accuracy if you are going to make the outside skin radar invisible... if you make the skin radar invisible the radar wave will go through to the internal structure.

    Do you even know what a corner reflector is?

    A 1.5m triangular corner reflector can generate a RCS of tens of thousands of metres...

    An SA-6 drone missile used for training SAM sites has a RCS of 0.1-0.3m with a normal nose cone but with a corner reflector can simulate up to a 5 metre RCS... With a radar transparent nose cone it has a RCS of 1m.

    So which is the best performance... a normal radar reflecting skin (0.1-0.3m), a radar transparent skin (1m) with a flat empty plate at the back, or internal bits and pieces that increase radar reflection (3-5m).

    Austin

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Austin on Mon Feb 27, 2017 5:45 pm

    Longish Interview

    Scientific director of the State Research Institute of Aviation Systems (GosNIIAS),YEVGENY FEDOSOV ABOUT THE PROSPECTS OF MILITARY AVIATION


    https://www.aviaport.ru/digest/2017/02/27/422309.html

    Mindstorm

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Mindstorm on Mon Feb 27, 2017 8:31 pm



    Austin wrote:Longish Interview

    Scientific director of the State Research Institute of Aviation Systems (GosNIIAS),YEVGENY FEDOSOV ABOUT THE PROSPECTS OF MILITARY AVIATION

    https://www.aviaport.ru/digest/2017/02/27/422309.html



    Thanks Austin.

    Is conforting once in a while openly read highly informed opinions ,from other people in the know, about subjects so often horribly twisted ,up theirs more inherent basis, in public media - "stealth" technology above any other -.

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    Isos

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Isos on Mon Feb 27, 2017 9:27 pm

    Mindstorm wrote:

    Austin wrote:Longish Interview

    Scientific director of the State Research Institute of Aviation Systems (GosNIIAS),YEVGENY FEDOSOV ABOUT THE PROSPECTS OF MILITARY AVIATION

    https://www.aviaport.ru/digest/2017/02/27/422309.html



    Thanks Austin.

    Is conforting once in a while openly read highly informed opinions ,from other people in the know, about subjects so often horribly twisted ,up theirs more inherent basis, in public media - "stealth" technology above any other -.


    Can you say us quickly what is said ?? Translations on Google are not that good. Thanks
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    Militarov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Militarov on Mon Feb 27, 2017 11:36 pm

    Singular_Transform wrote:
    Militarov wrote:

    Lets call it being realistic.

    So, what you think, compared to say US AD operators , is your capability and training on par with them or inferior ?

    We had more than adequate training pre 1991. we even had live fire trainings on regular basis till then, after that very few live fire trainings were conducted. We even used to travel to USSR and use their training facilities now and then.

    Equipment is... old, some of it in quite sorry state... i mean, we still have few P-15s around so figure.
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    Singular_Transform

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Singular_Transform on Tue Feb 28, 2017 12:00 am

    Militarov wrote:

    We had more than adequate training pre 1991. we even had live fire trainings on regular basis till then, after that very few live fire trainings were conducted. We even used to travel to USSR and use their training facilities now and then.

    Equipment is... old, some of it in quite sorry state... i mean, we still have few P-15s around so figure.

    Then why you moan?

    The personnel get out the most from the equipment ,and actually shown top level performance.


    The AD restricted quite well the operation of the air forces, and there was no military loss on Serb side due to that .

    The only reason why that was lost is because the US started to bomb the civilian infrastructure.

    And that is quite hard to protect with anything.
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    Militarov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Militarov on Tue Feb 28, 2017 12:22 am

    Singular_Transform wrote:
    Militarov wrote:

    We had more than adequate training pre 1991. we even had live fire trainings on regular basis till then, after that very few live fire trainings were conducted. We even used to travel to USSR and use their training facilities now and then.

    Equipment is... old, some of it in quite sorry state... i mean, we still have few P-15s around so figure.

    Then why you moan?

    The personnel get out the most from the equipment ,and actually shown top level performance.


    The AD restricted quite well the operation of the air forces, and there was no military loss on Serb side due to that .

    The only reason why that was lost is because the US started to bomb the civilian infrastructure.

    And that is quite hard to protect with anything.

    Suspect Right...
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    SeigSoloyvov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  SeigSoloyvov on Tue Feb 28, 2017 9:00 am

    Singular_Transform wrote:
    Militarov wrote:

    We had more than adequate training pre 1991. we even had live fire trainings on regular basis till then, after that very few live fire trainings were conducted. We even used to travel to USSR and use their training facilities now and then.

    Equipment is... old, some of it in quite sorry state... i mean, we still have few P-15s around so figure.

    Then why you moan?

    The personnel get out the most from the equipment ,and actually shown top level performance.


    The AD restricted quite well the operation of the air forces, and there was no military loss on Serb side due to that .

    The only reason why that was lost is because the US started to bomb the civilian infrastructure.

    And that is quite hard to protect with anything.


    ...They lost rough 2k men, about 60 types of armored vehicles and over 100 aircraft.

    considering how weak the AD was that is still a massively good job compared to what they had to fight sure. It showed that even a weak ass nation that really should have had it's AD taken out in a couple of weeks held of a much much much much bigger air force and a MUCH more advanced one with tech over 30 years behind it. That is an accomplishment and shows anyone who thinks the airforce can do jack of anything at large scale is wrong.

    But to say they took no military loss, I honestly don't know where you got that idea.
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    Singular_Transform

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Singular_Transform on Tue Feb 28, 2017 7:18 pm

    SeigSoloyvov wrote:


    ...They lost rough 2k men, about 60 types of armored vehicles and over 100 aircraft.

    considering how weak the AD was that is still a massively good job compared to what they had to fight sure. It showed that even a weak ass nation that really should have had it's AD taken out in a couple of weeks held of a much much much much bigger air force and a MUCH more advanced one with tech over 30 years behind it. That is an accomplishment and shows anyone who thinks the airforce can do jack of anything at large scale is wrong.

    But to say they took no military loss, I honestly don't know where you got that idea.

    Sorry, better to say "marginal losses" .
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    Rmf

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Rmf on Tue Feb 28, 2017 8:10 pm

    Singular_Transform wrote:
    Azi wrote:
    DETECTION is easy with long wave radar, the B-2 and F-35 never meant to be invisible for long wave radars.



    TARGETING is hard , because it needs precision and short wave length radar, and semi active radar homing that can work only with X band radars.


    See?

    The Serbian operators DETECTED the F-117 and B-2 aircrafts, but they never managed to TARGET them with the X band radars.




    Occam's razor : if coating can make something "stealth" then no one needs complicated and expensive shaping, all the stealth technology needs is a spray can and a monkey to spray it onto the air-plane.

    The stealth idea and technology 40 years old. And there is no magic paint.

    long electromagnetic wave will be scattered from the edges, and no paint can help this, only if it is extremely thick.


    not so fast, p-18 has 18 elements= 2x9 , while nebo-m has 7x24=168 aesa elements , .....thats 9,3 times difference just in antenna aperture , and with less transmit loses and less noise , nebo-m is a beast!  it has more power per element and can focus those beams in tight parts of airspace.
    recently some more information was released after 15 years in war diaries and computer reconstructions from crew memories.
    f-117 was detected by search p-18 at 23km, and aquired by guidance radar which works at I-band (9 ghz) at 18km , it did break lock but was reaquired at 16km. so 23 vs 16 km not much difference = about 30%.  
    https://en.wikipedia.org/wiki/I_band_(NATO)

    heres engagement display. in distance and height.

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    Rmf

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Rmf on Tue Feb 28, 2017 8:28 pm

    now there has been some information released from war diaries and computer reconstructions from crew memories about engagements , here some explanation about neva snr-125 radar and its transmitter uv-10 ,receiver  uv-11 f1 and f2 ,and missile link uv-12 each has its screen in cabin.http://www.ausairpower.net/APA-Engagement-Fire-Control.html




    left is top b-2 track and bellow f-117 track and missile going its way....

    right is f-117 left screen is the zoom , screen with larger  fov is right , 3 pictures from the top - 1. aquired aircraft , 2.missile in flight after boost phase ,and  3. missile closing in to f-117 for proxy detonation .
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    MarshallJukov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  MarshallJukov on Fri Mar 24, 2017 9:26 pm

    Azi wrote:
    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    - Second is to use RAM coating. RAM "absorbs" radar through interference (thickness) or excitation on molecular level, for example like water absorbing microwaves. In long wave range some RAM are loosing near all of their ability, some other retain more. There is a large selection of RAM based on different physic characteristics.

    - Third is geometry of object!

    Sorry to burst your bubble but:

    1. As glass is NOT invisible to light (the only thing that is 100% transparent to EM is vacuum) as composite materians are not fully radio transparent. Moreover, you just can`t make entire aircraft out of composites. In fact that is worst you can do. Composites are there absolutely not for RCS reduction but for mass reduction. The outer skin of an airframe is always made out of conductive materials in "stealth" aircrafts, that is NOT radio transparent alloys. Thats entirely made for the purpose of "stealth" as it is the only way to maintain some control over direction of reflected signal.

    2. You just posted utter gibberish. RAM utilizes basicaly same laws as antennas do. It absorbs EM radiation. And just as antenna, it needs to have specific geometry to be effective in a specific wavelength and direction. Just as antenna, to be more or less efficient in target wavelength, it MUST be at least within 1/16th of the size of that wavelength. Now, old P-18 has operating wavelength between 1,7m and 2,1m. That means in order to give ANY effect in that band your RAM must be as thick as 100mm. And to be anyhow relevant it must be 1/8th or less, so its like 200mm+. B-2 or any other VLO aircraft has its RAM coating in order of few milimeters or less, 2 or more orders of marginite below threshold of relevance.
    RAM never contributes over 10% of total RCS reduction even within milimeter wave band.

    3. Shape is ALL that matters in so called "stealth"
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    Isos

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Isos on Fri Mar 24, 2017 9:54 pm



    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    If it goes throught the material, it will be reflected by a material on the plane (like engines). Many composite materials transforms radiation into heat, that's the only way a material can reduce RCS. It would be funny to see with a OLS a F-22 illuminated by Mig-25's radar...

    The main rcs reduction is the geometry of the plane.

    IMO, F-22 is all propaganda. They say that the F-35 which is 30 years younger and cost as much if not more doesn't have a better RCS, a better radar, better electronics than a 30 years old fighter ... That's just bullshit. They never deploy them and if they deploy them it's in safe area.  

    I'm not saying it's a bad Aircraft but that it's role is to be used for propaganda, not air force. The french general of French airforce said that a 5th generation Aircraft is not needed because "stealth" is not important. And he knows what he is saying as rafale was already opposed to the F-22.

    Russian bears (which are full of electronic instruments) were intercepted by F-22 near the west coast. They probably turned on their radar to see how effective they are against f-22. The S-400 and Pak Fa dev takes all that in consideration.

    Now that this myth was studied they are introducing the F-35 in big numbers because they know that the small amount of F-22 won't be that usefull in a war as it doesn't have any ground capability, the number they have is very low, most of the aircrafts will be kept in USA and not deployed ashore because USA want to protect themselves first so they keep a majority in the Mainland. Imagine a russian-us war and Russia manage to destroy 3 of the 10 US carriers. The rest will be call back near the Mainland. And contrary to what majority of poeple think US is also for the quantity over the quality. Most of their stuff are not the best in their class. European stuff is generaly better but they have less of them. Leo 2 bettter than Abrams, Rafale better than F-18/16/35, Exocet better than harpoon, Meteor better than AMRAAM, Horizon destroyer better than Burkes ...and so on. But they are god enough and in big quantity to win a war.
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    kvs

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    Re: Is Russia safe from F-22 and Β-2?

    Post  kvs on Mon Mar 27, 2017 2:02 pm

    MarshallJukov wrote:
    Azi wrote:
    - First is to you use material that is invisible to radar, like glass to light. Many composite materials are invisible to radar, it goes simple through material without interaction.

    - Second is to use RAM coating. RAM "absorbs" radar through interference (thickness) or excitation on molecular level, for example like water absorbing microwaves. In long wave range some RAM are loosing near all of their ability, some other retain more. There is a large selection of RAM based on different physic characteristics.

    - Third is geometry of object!

    Sorry to burst your bubble but:

    1. As glass is NOT invisible to light (the only thing that is 100% transparent to EM is vacuum) as composite materians are not fully radio transparent. Moreover, you just can`t make entire aircraft out of composites. In fact that is worst you can do. Composites are there absolutely not for RCS reduction but for mass reduction. The outer skin of an airframe is always made out of conductive materials in "stealth" aircrafts, that is NOT radio transparent alloys. Thats entirely made for the purpose of "stealth" as it is the only way to maintain some control over direction of reflected signal.

    2. You just posted utter gibberish. RAM utilizes basicaly same laws as antennas do. It absorbs EM radiation. And just as antenna, it needs to have specific geometry to be effective in a specific wavelength and direction. Just as antenna, to be more or less efficient in target wavelength, it MUST be at least within 1/16th of the size of that wavelength. Now, old P-18 has operating wavelength between 1,7m and 2,1m. That means in order to give ANY effect in that band your RAM must be as thick as 100mm. And to be anyhow relevant it must be 1/8th or less, so its like 200mm+. B-2 or any other VLO aircraft has its RAM coating in order of few milimeters or less, 2 or more orders of marginite below threshold of relevance.
    RAM never contributes over 10% of total RCS reduction even within milimeter wave band.

    3. Shape is ALL that matters in so called "stealth"


    Point (2) is not the primary issue. The only reason why the RAM needs to be a certain thickness is that absorption is wavelength dependent. A thin sheet of
    any material becomes more and more translucent to incoming EM as the wavelength is increased. And more opaque as the wavelength is shortened.
    In the case of gamma rays the penetration is associated with their high energy as per the range-energy relations for different materials and the fact
    that they have very short wavelengths does not mean that they will not penetrate deep and through objects. As discussed in this thread already, it
    is the longer wavelength "radar" signals that are the most effective at detecting B-2, F-22, etc. So the RAM fix is a lost cause since very thick layers
    need to be applied to absorb the incoming signal and emit it in some other wavelength ranges depending on the chemistry of the RAM coating. This
    brings us back to your point (3), which is correct since the RAM can't do the job by a long shot.

    Point (2) is interesting since the interaction of EM fluxes in RAM and the metal skin of the aircraft will generate an antenna-like EM field of its own.
    Depending on the geometry of this field, there may even be significant backscatter.
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    MarshallJukov

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    Re: Is Russia safe from F-22 and Β-2?

    Post  MarshallJukov on Wed Mar 29, 2017 12:40 am

    kvs wrote:The only reason why the RAM needs to be a certain thickness is that absorption is wavelength dependent.  .

    That was exactly my point. Also, gamma rays are high energy photons which is not the case on our topic as they have different properties than radiowaves. However new type of photonic radars is comming. Which supposedly make "stealth" completely obsolete by all means.

    Azi

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    Re: Is Russia safe from F-22 and Β-2?

    Post  Azi on Mon Apr 03, 2017 6:05 pm

    MarshallJukov wrote:
    1. As glass is NOT invisible to light (the only thing that is 100% transparent to EM is vacuum) as composite materians are not fully radio transparent.
    Invisible was not the correct word, that's right (englisch is not my native language!). The correct word is transparent. Normal glas has a transmission value of ~95% in visible light spectra. It exist special glas with higher transmission values.

    There are many composite materials wich don't interact with radar or microwaves. Key point is the absence of electric or magnetic dipole or multipole moment. So most plastic materials without that dipoles or multipoles are transparent to radar. Best example is plastic dish in a microwave oven, you can heat water in it but the plastic dish will not warm up.

    MarshallJukov wrote:2. You just posted utter gibberish. RAM utilizes basicaly same laws as antennas do. It absorbs EM radiation. And just as antenna, it needs to have specific geometry to be effective in a specific wavelength and direction. Just as antenna, to be more or less efficient in target wavelength, it MUST be at least within 1/16th of the size of that wavelength. Now, old P-18 has operating wavelength between 1,7m and 2,1m. That means in order to give ANY effect in that band your RAM must be as thick as 100mm. And to be anyhow relevant it must be 1/8th or less, so its like 200mm+. B-2 or any other VLO aircraft has its RAM coating in order of few milimeters or less, 2 or more orders of marginite below threshold of relevance.
    RAM never contributes over 10% of total RCS reduction even within milimeter wave band.
    Thanks for your very nice words...utterish gibberish!

    RAM is based on two effects. The first effect is pure absorption of EM waves. Radar, or let's better name it microwaves are electromagnetic radiation. The photons have a electric and a magnetic field vector, this fields can interact with with electric or magnetic dipoles (or multipole). This is exactly what happens in a microwave oven, the photon interacts with the dipole and pushes the molecule, so EM energy is transformed into heat. This effect happens over a broad spectra and is of course best at resonance frequency, if you go away from this resonance frequency the effect is weaker. This means for RAM that absorption will still occur at longer wavelengths, but of course not so good. Good absorbers are ferrites, they have a great dipole moment below the Curie Temperature (for most ferrite not very high ~200 °C).

    The second effect is destructive interference, and at this point you are correct the RAM should have a thickness in relation to the specific wavelength. In Salisbury Screen, "in which a sheet of resistive material overlays a conductive back plane, the two being separated by dielectric material whose thickness is 1/4 of the subject radar's wavelength" (quote from materials today). There are many ways to craft "resonant RAM", a good way but very thick are pyramidal absorbers.

    MarshallJukov wrote:
    RAM never contributes over 10% of total RCS reduction even within milimeter wave band
    LOL! Have a look Radar absorbing material design Yuzcelik, Cihangir Kemal!

    MarshallJukov wrote:3. Shape is ALL that matters in so called "stealth"
    Shape is a part of stealth concept but it's not "ALL"! If shape is all, why Su T-50 has RAM coating? Why nearly all stealth objects have a RAM coating?

    I'm not a Murican fanboy! I'm not a stealth fetishist! I'm scientist and must admit the concept of stealth is not bad at all. It's not the "Wunderwaffe" but in some situations it can give you the advantage. There are many systems to counter stealth or to reduce the advantage that stealth gives, of course!


    Last edited by Azi on Mon Apr 03, 2017 6:27 pm; edited 1 time in total

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