FalconDudeWat. There has been dozens of small changes that are visible externally just compare prototypes, not to mention hundreds of changes inside, even ignoring structural stuff.
Dozens? Other than the intakes at the root of the stabilizers and some changes in the vents(?) behind the canopy I can’t remember any other -non minute- changes. I could be wrong, but I think the F-22 has changed more than the T-50 in its course from prototype to serial.
Of course the next batch may prove me completely wrong.
besides I was merely saying that people still expect this:
[ATTACH=CONFIG]244924[/ATTACH]
To turn into this somehow:
[ATTACH=CONFIG]244925[/ATTACH]
which is beyond logic …
FalconDudePerhaps, but there have been no changes -bar structural ones- since the design was unveiled. I would think chances deminish as time goes by.
FalconDudeFinger crossed. :3
Would love to see somethin new like.. new IRST fairing or even new exhaust nozzle.
I believe the consensus is that the T-50 is pretty much in its final form now. Don’t expect any changes.
FalconDude…or may not…
List of said problem for those of us who are not blessed with knowledge of Russian ?
FalconDudeMiG-29K/KUB will be on the carrier, Su-33 will be ground based fighter to protect Kola peninsula and Arctic region. It will have sense to modernize them with N001VEP radar to give them anti-ship capabilities, which MiG-31BM doesn’t have. They both will protect the gate between Murmansk and Franz Joseph islands.
Is this because the Su-33 has been deemed to not be capable (or suitable) for carrier operations anymore?
FalconDudeNOTE FOR MODERATOR(S):
Would it be a good idea to move the discussion contained in postings 929, 936, 941, 942, 946-949, and 951-959 to the ‘ECM pod can reduce RCS?’ thread? Folks who come to this thread to discuss the PAK-FA must be getting rather tired of this digression into the world of EW.
Well, the mods haven’t moved anything.
What do we do now? I kinda want to see this thing through..
FalconDudeFalcon, here you go:
http://www.sciencedirect.com/science/article/pii/S1270963815002254
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5655941I´ve read severall diferent articles from reputable publications describing severall diferent teams in severall diferent countries testing what we would call “active cancellation”.
Ex: Armada International
Although this discussion should have been moved to the other thread, I’ll do a quick reply.
Did you download the IEEE paper? I did, and read it. Here is the conclusion verbatim
“The results presented here may be summarized as follows:
the scattering field is reduced effectively and efficiently
through interaction between the cancellation signal and echo
signal. Restrained by length of the paper, we only analyze the
cancellation case of LFM of 10 GHz, and the similar results
can be obtained for the other frequencies. Though the
influence of sea-face and the smoothing error are ignored, the
proposed method in this paper can provide a novel method for
warship stealth. Consequently, compared with shape stealth
and material stealth, the stealth measure is extended to
frequency domain and the effect is improved through using
smart cancellation stealth measures. Simultaneously, it can
also provide an effective supplement for the conventional
stealth measures.”
As you can see, they don’t claim it works. They list all the simplifications they had to make to make this worth while!
Also if you are involved with academia you know papers don’t always deliver what they suggest they do.
Nonetheless, I don’t want to appear to be strong-headed. There is the concept of active cancellation. That works to an extend. I brought up the concept of noise cancelling headphones. They don’t work very well, despite what Mercurious suggested, we have two in the lab being tested at the moment, couple of the most expensive you could buy and they are not doing that good. However, they do work to an extend.
Now, moving on to the concept of active cancellation for stealth. My point, view, thesis, argument, whatever you want to call it ,is that active cancellation of incoming radar signals is impossible. You want to argue that some reduction in signature due to active transmission of cancellation signals can be achieved. Yes that is possible, that is how the noise cancellation headphones work anyway. The point is they can never cancel completely the incoming signal. If you can’t do it for sound, imagine doing it for EM radiation signal that is actually encoded and varied. You can’t have it both ways. You can’t on one hand argue (not you, in general) that radars, are encoded, jamming resistant, LPI etc etc.. and then just blindly accept that a complex surface such as an aircraft, or a ship can simple generate an out of phase counter signal in 0 time and cancel the echo!
FalconDudeHang on a minute! These exchanges only started because you had claimed that active cancellation was impossible. I have responded by citing – from open sources – research work that was carried out in this field by MBDA and Thales – including a statement by a named senior official to the effect that some success had been obtained during flight trials. So I have given evidence that active cancellation is not impossible. And that was all I set out to do.
If you have difficulty in understanding how the technique works, then that is your problem, not mine, nor that of my contacts in the EW industry. My role in explaining the basics of EW to young engineers ended several decades ago.
I have no experience with commercial noise-cancelling headphones, but a military active-cancellation headset that I tried in the mid-1980s was very effective.
There is no need for the ‘processor’ and ‘generator’ shown in your diagram. The pulse train that needs to be transmitted already exists at the output of the receiver. The only manipulations required are a reversal of phase and adjustment of the amplitude.
Such is reality for many types of deception jamming involving signal manipulation. The time needed for pulse detection and manipulation will often mean that the leading part of the pulse is likely to be unjammed. The job for the EW designer is to keep that unjammed period to a minimum in order to minimise the degradation suffered by the jamming, while the task of the radar/ECCM designer is to exploit that unjammed period by using techniques such as leading-edge tracking.
NOTE FOR MODERATOR(S):
Would it be a good idea to move the discussion contained in postings 929, 936, 941, 942, 946-949, and 951-959 to the ‘ECM pod can reduce RCS?’ thread? Folks who come to this thread to discuss the PAK-FA must be getting rather tired of this digression into the world of EW.
Yes, the discussion should be moved to the other thread, I agree!
FalconDudeWhat you are missing is that radar pulses have duration.
It would be impossible for a purely reactive active cancellation system to achieve 100% efficacy, but there is no paradox problem with a hypothetical system that could react within the duration of a single pulse. The question of course would be just how much of a pulse it could cancel, how effectively it nullified the pulse while it operated, and of course how much it overshot the pulse after the pulse ended.
On the contrary, pulses make the whole process harder not easier. Especially since systems can vary the timings between pulses as well as pulse duration.
have a look at my crude diagram below. It is pretty much the same reason that active noise cancellation headphones don’t work very well. Any they only have to cancel soundwaves. Imagine having to defeat a system that can even classify you by the type of reflection signature you have.
[ATTACH=CONFIG]244523[/ATTACH]
FalconDudeReally? That must be the reason why my professional services as a defence analyst are still in demand now that I’m well past normal retirement age.
I find it hard to reconcile your claim that active-cancellation is impossible with my own memory of being at a technical conference (‘Missiles 99’ in London) where the subject had an early unclassified but non-public-domain mention.
Had there been a fundamental flaw to the concept, why did the many highly qualified engineers in the audience not mention this during question time at the end of the presentation?
And before you point out that I merely claim to have attended such conferences, I would point out that you do not have to take my word for what was said during that event. While the conference proceedings are probably not in the public domain, the conference highlights were reported at the time in technical press.
While we have no information on whether the active stealth concept proved viable for operational use, particularly for missiles (which may have been the first intended application), at least we know from one of the Jane’s reports in 2002 that “Jean Viala, Group Head of Applied Research and Technology for MBDA, says the flights have produced the same substantial ‘stealth effects’ as shown by initial anechoic chamber testing.” Viala’s claim of “substantial ‘stealth effects'” during flight trials seem impossible to reconcile with your claim that “Active cancellation IS NOT POSSIBLE!”.
So I trust you will understand why I prefer to accept the Jean Viala version of the situation rather than yours.
I’ll accept anything you want, the moment you provide some -any- explanation of why what I am stating is wrong!
Call your friends, email them, whatever….they don’t have to give up any company secrets, they don’t even have to tell you why their “systems” work, they just need to tell you why I am wrong!
Hopsalot for example attempted to provide an explanation of why active cancellation might work. You haven’t so far.
FalconDudeSo at next Eurosatory I should explain to the Thales electronic-warfare specialists who worked on their company’s active-cancellation research that the time and money their company spent on this technology was wasted because FalconDude could have explained to them that “Active cancellation IS NOT POSSIBLE!”?
And that this is impossibility is due to a “simple matter of reality” that they in their foolishness and technological ignorance did not comprehend?
I am always happy to discuss and debate areas of defence technology in which I have at least some expertise (and am content to remain silent on those topics in which I do not). But such discussion and debate needs to be based on reality – in this case, that reality includes reports from the technical press which some members of our forum took time to unearth and post here. Dismissing the authors of these reports as “Jane’s geniouses” is hardly a reasoned response.
The fact that you or I may not understand one aspect of a technological subject is not a reason for denying that the subject is a viable one. That is my view, anyway. If it comes over as arrogant, then so be it.
I seem to recall from Dr R V Jones’ biography that one argument used against the existence of the A-4 rocket was that a power source of small size yet with the output needed to pump the required amounts of propellants into the rocket motor would have been a potent powerplant for a propellor-driven fighter. Since no such propellor-driven super-fighter was known, it logically followed that the power source did not exist, so therefore the reported A-4 rocket did not exist. The impacts in London of the first A-4 rockets to the fired against the UK was an example how reality can sweep away speculation.
Yes
It is clear you do not understand the subject matter, and it is also clear that you don’t read the posts others make. Perhaps you pick keywords and you respond accordingly.
You can tell the people in your next presentation whatever you wish because all you have done in your response post is to claim you go to presentations and claim you know these people!
Have you any scientific or otherwise argument against my brief albeit extremely real explanation of why active cancellation of incoming unknown characteristic radar signals is impossible? Your post suggests not!
Active cancellation of a KNOWN signal is not impossible if you know that signal’s characteristics before hand! But not if you have no idea what is going to be broadcasted at you!
You would need to tap into relativistic paradoxes to be able to do what you suggest is possible.
And just because I want to be fair and not arrogant as some people in here, I’ll go as far as saying that perhaps (as I stated in the original post you responded to) predictive probabilistic active cancellation may have some percentage of efficacy but that would take some seriously advanced hardware and algorithms!
FalconDudeEvidence of French flight testing of active cancellation has already been offered in the ‘ECM pod can reduce RCS?’ thread. I suppose that it is possible that you know about the subject than Thales and the Jane’s ….
Mercurius I detect arrogance and sarcasm in your post and I don’t like it!
You like to get clever with me, I’ll pick up the glove.
Active cancellation IS NOT POSSIBLE!
it is not because I am clever, it is because of the simple matter of reality!
The aircraft has to process the incoming radar signal and then produce the necessary cancellation counter signal. Since processing is not instantaneous in this universe’s reality, it is impossible to actively cancel an incoming signal of which you don’t know the characteristics of since you will always lag in the time domain due to the necessary processing time.
How’s that?
You think Jane’s geniouses you hold in high regard will have an issue with that?
FalconDudeIn other words, active cancellation?
real-time active cancellation is not possible. Predictive cancellation is more likely but that would be really something!
FalconDudeWell the USAF have been around from both Turkey, Iraq and other nearby countries.
We have the USAF F-15, F-22. We have SA with their F-15’s
We have Israel with their assets.
The small contigency of Russian jets in Syria is practical surounded and grossly outnumbered.
And the Russians are not intimidated.. Or maybe they are..
But Surely when the Turkish AF get their first F-35! The Russians will feel intimidated..
Don’t you see how silly this is?
Intimidated by the capabilities of the aircraft. Not by anything else. Reductio ad absurdum will not go far in this case.
FalconDudeYou realize that is what this is, right?
No, not yet. These are, for the moment, isolated accounts. We will have to wait a little while longer.
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