ErkokiteBut then you base your active cancellation on a fixed model it seems; my proposal was to avoid that by continously analyzing the incoming signal. In theory it should be simple; the FFT in combination with several antennas on the a/c should give the needed information on frequencies, phases, and amplitudes. Then it’s just to generate the same frequencies with a phase shift… The opponent may do things like frequency hopping however they do need to spend sufficient time on a specific frequency to allow their system a decent sample on that frequency. Switching to another frequency would be detected instantly by the system which would automatically start to emit on that new frequency. And the “waveform” is also taken care of by the Fourier analysis.
My assumption was that one would develop electronics that was several orders of magnitude faster than what’s out there today. That would require enourmous investments in some “break-through” technology of course. But it would be needed if one wanted to do on-the-fly Fourier analysis of incoming signals in the giga-hertz range and signal generation in real-time of the cancelling signal. It sounds like science fiction however it still may be possible to do.
DRFM systems that use superconductor microelectronics do exist:
http://www.hypres.com/pages/new/bnew_files/navair.pdf
I read something about Raytheon experimenting with similar systems. I’m sure Thales and MBDA have also done similar research.
ErkokiteI don’t know why you guys missed the “juiciest” part of the news report :-
“Its search even contains the Gas Turbine Research Establishment GTX-35VS Kaveri, still in development for India’s Aeronautical Development Agency Tejas light combat aircraft.“
It’s quite plausible actually. All their options like M-88 and RM-12 are in the 78 kN to 80 kN range. Kaveri is 81 kN engine and moreover, it is a flat-rated engine. SO, it does have a good chance of being selected by Japan.
Now, the question arises how does Japan expect to buy Kaveri, which is still under development in it’s own nation ? The answer is that IAF wants more from the Kaveri i.e. upto 85-88 kN (approx). It has already successfully demonstrated 81 kN of thrust.
Hence, compared to the GE-404 and M-88, Kaveri stands a very good chance of being selected. It’s cost is also likely to be much cheaper than these western engines.
It will not be selected because it is still very much under development, and the Shin-Shin project is likely only looking for an interim engine as there is a domestic Japanese engine under development. Last time I checked, the Kaveri was the main culprit behind the LCA delays, and GTRE will be receiving aid from SNECMA just to complete the engine. The program has been over 20 years in development so far and still has yet to meet requirements or match the thrust/weight of western engines.
ErkokiteI am not trying to argue but do I recall correctly that Typhoon has less drag with four semi-recessed AMRAAMs than without them?
I heard this as well.
ErkokiteRobban
Having a canard is not a guarantee of being better than a tailplane, a fighter is a product of thrust and lift plus control surfaces.
The Viggen and Kfir for example were completly outmatched by fighters like the F-4 and MiG-23, the sustained turn radius of a Viggen is below of what a F-4 and MiG-23 can achieve and way below what an F-15 does.
The MiG-29 also has better sustained turn rate than the Gripen.Now the F-22 has an excess of power and a huge wing, this is quit similar to an F-15 versus Viggen comparation
To be fair, the Kfir was a Mirage III with non-moving canards. And the Viggen’s canards were intended mainly for STOL purposes.
ErkokiteMadrat
You have to consider the following points.
Any stealth fighter uses basic radar reflection angles, it is around 30 degrees, this is based upon the mathematics of Ufimtsev , basicly all the aircraft surfaces and edges should be align upon that angle
I think 30 degrees refers to the Keller cone around edges outside of which Keller’s geometrical theory of diffraction and Ufimtsev’s uniform theory of diffraction are unable to predict diffracted electrical fields. This problem is purely predictive and a limitation of these models. It is remedied by using the method of equivalent edge circuits or the method of moments. Many modern RCS prediction codes use the method of moments and are not subject to this difficulty, and thus the angle of 30 degrees has no significance. That is my understanding, but I am not an LO expert.
An RF or LO engineer could probably correct me if I am incorrect.
ErkokiteI doubt there would be any Al-31 retrofit. If yes, then we would easily see from pics. More likely, Russians could help Iranians develop and complete manufacturing process for vital TF30 parts.
Radar is a different story but that would very soon become visible on available weaponry carried by IRIAF Cats. I don’t think that any Russian radar can guide Sparrow or Phoenix.
Perhaps they could be modified to guide these missiles. Or who knows? Perhaps, their Phoenixes and Sparrows are beyond their shelf lives (does this happen?) and they decided to use Russian missiles instead.
Russia has offered to integrate the Al-31 in the past. The Al-31 is in the same class as the F100 engine in terms of size and performance. I assume some modifications to the airflow management system on the F-14’s inlets (this should be doable, now information on the system is publicly available). The Al-31 is pretty tolerant of varying inlet conditions anyway, so maybe this isn’t a huge issue.
I don’t know, but I would sure as hell bet that these engines and radars are not domestically designed by Iran. Perhaps they figured out a way to copy the radar and engines, but manufacturing fighter aircraft turbofans is VERY difficult.
ErkokiteIf in the testing stage, it is decided that a design is undesirable, why the heck would you make an operational version, in order to get more experience with it? That’s the very definition of counterintuitive.
I think that in the US, fighter development at this point in time was focused on LO technologies. As canards can cause difficulties with RCS, these were considered undesirable in new fighter designs.
Prior to this point (early 1980’s and onward), I don’t think the FBW technology for unstable, supersonic, tailless aircraft with movable canards existed- as an example, the Mikoyan Ye-8 was axed because it was too difficult and unsafe to control.
So by the time the FCS technology existed for aircraft like the current Eurocanards, the US had already decided that canards (especially moving ones) didn’t fit their needs or targets for VLO fighter aircraft.
European designers were not focused on VLO at the time, so they went ahead and designed aircraft that fit their needs and targets, which were presumably very different from those of the US.
This is just conjecture on my part, but it is a fitting explanation, I think.
ErkokiteBut AESA radars are considerably more sensitive than other arrays, and thus more efficient. They don’t require as powerful signal for a given range.
Not to be nitpicky, but modern PESA antennas like the RBE-2, BARS, APQ-164, and Irbis-E use T/R modules that use the same receive path as an AESA module. The difference between the two is that for the transmission path, each AESA T/R module has its own high power amplifier, whereas a PESA shares an amplifier (like a traveling wave tube) for all modules. Of course, there are still many advantages of AESA over PESA for reasons you described in your previous post.
ErkokiteSo what does it look like? Gamma rays? Microwaves? X-rays?
LOL…
Like noise.
ErkokiteFrankly I always have been rather bemused by the avionics, radar and missile deal with France for the JF-17. I have always felt there are better sources in the west for the systems probably at a better price.
Firstly Radar: Selex Galileo Grifo S-7. A company and radar they already have a relationship with.
Avionics: Selex Galileo and SAAB Avitronics. They already have a relationship with these companies via the pre mentioned radar and the AEW deal. This means Swedish and South African avionics or Italian/British.
Missiles: Denel A-Darter and R-Darter. Again a prior relationship and already stated interest in these missiles.
Thats not forgetting the rather improved Chinese systems and missiles we have seen recently.
But they would have to be integrated together. The French system provides a complete package (at a price).
ErkokiteRafale and Su-27.
ErkokiteMore on this from Aviationweek’s Ares blog, with a nice high-resolution photo of the actual installation on Rafale:
As Nicolas said, like LPI radar? While the devil is clearly in the details, keep in mind that, like a DRFM deception jammer, an active cancellation system would not be emitting unless the host aircraft is being illuminated by enemy RF.
Personally, I think the active missile launch warning system on the Typhoon is a much bigger concern in this regard since it needs to be transmitting constantly to perform its function. Since it operates in the MMW band IIRC the rationale is probably that most threats will not be equipped with appropriate ESM bandwidth to detect it, but this assumption will become less tenable as time goes on. It does apparently offer the distinct advantage of being able to track missiles and provide evasion cues to the pilot as a result.
Eurofighter is offered with the PIMAWS passive infrared system for MAWS, but I don’t know if anyone has bought it yet. Hopefully someone picks it up for the reasons you mentioned.
Also, that new DDM NG thing looks amazing- apparently they’re going to add DIRCM at some point. Looking ahead to the Rafale of 2015-2018, we have:
AESA
DDM NG with DIRCM
Active Stealth
9t engine
More SPECTRA modes
METEOR
OSF-IR
Helmet Mounted Display (?)
and who knows what else. I hope it will give the F-35 a nice bit of competition.
ErkokiteErkokite, not too long ago french were the top supporter of lifting the arms embargo. They wanted to sell military stuff directly to china. Why this sudden change over something like this, which is not exactly top of the range if you look at the latest gadgets on rafale. A year or so ago there were similar reports though US concern wrt tech prolif was the cited reason-even when US is supplying more advanced stuff to Pak. As for taiwan connection, last i heard of those M2Ks was when when taiwanese were thinking of mothballing them cos of prohibitive operating costs.
I’m making generalizations. You make a good point though. I was just illustrating that it is not irrational to refuse to sell things based on concerns about unauthorized ToT. I apologize to Type59 and the rest of the forum for my hostility.
ErkokiteIt strikes me as shady, if France denied Pak sale because they dont want industry in Pak to enhance itself, through limited ToT. Maybe thats why theres hate against China, because they are not content to just accept the product, but also be able to learn from it, build it and furthur enhance product. Japan got same hate when they were modernising.
If by “learn from it, build it and furthur enhance,” you mean tear-apart, copy, violate IP rights, steal classified technology, and turn around and sell cheap copies, then sure- that’s exactly why there is hate against them. Just ask Russia about the Su-27SK’s they sold the Chinese. What they are doing is blatantly illegal, and extremely unethical.
Of course they don’t want Pakistan to get their equipment- because next thing you know, they’ll turn around and give it to China and China will be using MICA and Thales RDY technology in their missiles and radars for which they did not acquire a license or production rights. Either that or they will use it to figure out how to jam or disable technologies on the Taiwanese Mirage-2000’s. And it could potentially give them an extra edge over potential competitors (military and industrial) in the west. It doesn’t make sense to turn technology over to a potential industrial or military competitor.
That would be like Toyota licensing one of their vehicles to Hyundai, then having Hyundai turning around and giving the design to Ford without authorization, who proceeds to make and sell a copy of the design to compete against Toyota. In the west- you pay massive fines for this, and jail time is certainly possible too. Except this time, there is national security at stake. Thales, AdA, MBDA, etc… have spent billions developing these technologies and they give the AdA and other users a military advantage over adversaries. To risk leaking the technology to an adversary (such as China) could potentially allow them to circumvent this military advantage or to make copies that would compete against French arms in the international market.
ErkokiteActive cancellation could, in a sense, be considered the ultimate outgrowth of DRFM jamming.
Sign In
