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Rafale 2018 Thread: Europe's best Eurocanard

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  • halloweene
    Rank 5 Registered User
    • Jan 2012
    • 4342

    You might think, this part is small and negligible but leading-edge-tracking (aka taking measurements not according to where the center of the return signal is but rather at the leading edge .All RGPO/RGPI cover pulse jamming tends to lag the targets returns by some increment of time) is actually a very common ECCM method
    Can't agree more. Albeit not magic wand (neither active cancellation ). Leads to a loss of bunch of infomations.

    All form of jamming ("active cancellation" included), need a certain level of J/S ratio to be effective, in that sense the jammer need to radiate at sufficient power to be effective.
    Different kind of jamming will have different requirement for this J/S level
    .

    The idea is to send signal in a very narrow angle (way under 1) so as not to need to much energy.

    About perect knowledge (or so) of configurations/anle, each new config is tested for WEEKS in Solange testbed (anaechoic chamber).

    Which makes active stealth a desirable tool, among many others.

    Comment

    • garryA
      Rank 5 Registered User
      • Dec 2015
      • 1120

      halloweene
      The idea is to send signal in a very narrow angle (way under 1)
      The jamming beam width (angle) will be frequency dependent because for any certain aperture area and frequency, there is a limit on how small (focused) your beam can be.
      I don't think Spectra can transmit jamming beam with 1degree beam width in X-band though, the transmitting aperture certainly isn't big enough for that task IMHO , you need a transmitter with aperture size similar to fighter FCR to achive that
      Click image for larger version

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      Comment

      • halloweene
        Rank 5 Registered User
        • Jan 2012
        • 4342

        I'm not good enough in RF to answer. The only thing i know is that jammers are AESA.

        Comment

        • garryA
          Rank 5 Registered User
          • Dec 2015
          • 1120


          The limitation i was talking about apply for all kind of transmitter, whether AESA or not.

          Comment

          • halloweene
            Rank 5 Registered User
            • Jan 2012
            • 4342

            Lost in translation with FCR

            BUT if you wish i can ask to a pro
            Last edited by halloweene; 5th January 2019, 17:28.

            Comment

            • garryA
              Rank 5 Registered User
              • Dec 2015
              • 1120

              FCR is fire control radar, i meant your transmitting aperture need to be around that size if you want your beam width to be 1 degrees or around that value ( assumming X band, obviously if you transmit at higher frequency then the aperture can be smaller, and vice versa)

              Comment

              • XB-70
                Rank 4 Registered User
                • May 2018
                • 316

                garryA

                Deceptive jamming is not the same as noise jamming in the sense that they attempt to inject false information that can be interpreted as real return instead of only simply blank out the real return like noise jamming.
                Yes, but that is like comparing an apple to an apple (which may have different sizes and hues but are both apples). With either approach, the aircraft scanning with radar will get a return from the aircraft employing jamming. With active cancellation there will be no return. (Now we are talking apples to oranges!)

                1) That correct, but while the signal the threat radar received will be weaker, the pulse length is the same.
                But what I'm getting at is that at a great enough distance, it may not matter. Every electronic device has a natural noise floor, and a signal has to be above that floor to be registered. The Rafale can register the pulses from a targeting radar at a greater distance than that from which the targeting aircraft can get a proper pulse - because it has to attenuate by 1/d^2 again. (The converse is also true though, and the capabilities of both aircraft's RWRs would have to be assessed here. My point was only that it may not matter!) And, again, if it does show up for a mere display frame or two it likely won't matter then either.

                2) That assumption is only correct, if the radar use a constant frequency/ PRF rate, because after the initial delay, your jammer can adjust to completely silent enemy radar (since you now know exact frequency and phase of reflected signal in the future). However, if adversary radar constantly frequency hopping and jitters their PRF randomly, then there will be a part of each individual pulse (or sub-pulse in case of pulse compression) that you can't "cancel"...
                Nope! Rather your counter argument is only true if the French tried a strictly real time approach. If you look back at my older posts you will see that I have said a few times that I do not believe that the French technology would work against an unknown radar system. This is because I do not believe that they are using a fully real time approach, and I don't believe they can.

                US stealth technology is strictly a real time approach. It is based off of shaping and absorbent properties of materials. The RF energy emitted by a radar system is a form of electromagnetic energy. It has an electric field component and a magnetic field component. With conductive absorbers the electric part of the field interacts with the electric field within the absorber material, altering it, which imparts kinetic energy to the conductive particles which is then dissipated as heat. With magnetic absorbers it is the same thing, only interactions between the magnetic fields. Since it is electric field-electric field or magnetic field-magnetic field interactions they happen at the speed of light and so are instantaneous - real time. And there is a particular type of absorber that the French are trying to mimic - one which reflects the non-absorbed portion with a 180 degrees phase shift.

                Click image for larger version

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                But the French have a problem since they are trying to use *electronic warfare*. Electrons in a conductor travel very fast, but they do not travel at the speed of light. Thus, the electronic processing is not instantaneous. And thus you cannot use a full real time approach to achieve full cancellation (you would always be reacting to events with lag). But engineers know how to cheat!! A phase shift is the same thing as a time delay. To cancel the reflected signal all you have to do is calculate a good time to start emitting the exact same signal! The time you choose will be such that the two signals (reflected and yours) are 180 degrees out of phase and thus cancel one another. So their system simply needs to first analyze the incident radar signal and determine what it is, pull characteristics of it out of memory, and then do some final processing to account for attenuation of the reflected wave, doppler effect and such (the time needed for these calculations are also precalculated and used for the final phase shift). Then you start transmitting. A proper radar return is sent back while the upfront analysis is being done but after that - practically nothing. And if it shows up for a frame or two it won't really matter.

                So there are some differences between US and French technologies.
                1) Theirs is only as good as the intelligence put into the mission file. If you guess wrong on what threats you might find then they might not have the proper characteristics stored in memory.
                2) Electronics still takes time to process information. If you light up a US stealth aircraft with 20 radars it doesn't matter. The shaping and absorbers instantaneously reacts with all of them. The French system will have to process them a little at a time and will (at some point) be overwhelmed.
                3) US tech is fine against unknown radars; the French tech isn't.

                BTW, this actually isn't a revolutionary thing. If you want to look into an application of where a hybrid approach like this is used (and has been for a long time), read about 3D graphics. You have the problem of determining how light emitted from various sources interacts with the environment and finally registers in your eye. Some of this you calculate real time with ray tracing. Some of this you precalculate - before runtime - and you simply fetch the resulting lightmaps, specular maps, etc. from memory as needed to touch up brightness, glossiness and such where you need it. You don't have infinite processing speed nor infinite memory - and so you find a finite combination of both that works!

                You might think, this part is small and negligible but
                leading-edge-tracking...
                After the upfront work is done there won't be any leading edges to trigger on.

                Anyways, this has gotten OT for the Rafale thread and so I am leaving it. I don't mind discussing it further on a dedicated thread.

                Comment

                • halloweene
                  Rank 5 Registered User
                  • Jan 2012
                  • 4342

                  Well, first of all the scheme you give is interesting, but will only work for a defined wavelegnth. Some 'simple and fast) electronic systems are able to do near real time treatment, much faster than the duration of a pulse.Of course, you still have the leading edge (remember i was the first to quote it in the discussion).

                  Leading edge tracking has two issues : first there is a huge loss of information. Second, you do not want to use it until you are sure you need it. Nothing is perfect in this world...

                  Comment

                  • St. John
                    Rank 4 Registered User
                    • Jan 2018
                    • 568

                    Based on what we know of the F-22/F-35, it works over a range of frequencies and definitely in the X-Band.

                    Comment

                    • garryA
                      Rank 5 Registered User
                      • Dec 2015
                      • 1120

                      XB-70
                      But what I'm getting at is that at a great enough distance, it may not matter. Every electronic device has a natural noise floor, and a signal has to be above that floor to be registered. The Rafale can register the pulses from a targeting radar at a greater distance than that from which the targeting aircraft can get a proper pulse - because it has to attenuate by 1/d^2 again. (The converse is also true though, and the capabilities of both aircraft's RWRs would have to be assessed here. My point was only that it may not matter!) And, again, if it does show up for a mere display frame or two it likely won't matter then either.
                      My point is because the pulse duration doesn't get shorter if the ECCM function of adversary radar can use leading edge tracking against RGPO and RGPI, it should be able to do the same against active cancellation.

                      XB-70
                      But the French have a problem since they are trying to use *electronic warfare*. Electrons in a conductor travel very fast, but they do not travel at the speed of light. Thus, the electronic processing is not instantaneous. And thus you cannot use a full real time approach to achieve full cancellation (you would always be reacting to events with lag). But engineers know how to cheat!! A phase shift is the same thing as a time delay. To cancel the reflected signal all you have to do is calculate a good time to start emitting the exact same signal! The time you choose will be such that the two signals (reflected and yours) are 180 degrees out of phase and thus cancel one another. So their system simply needs to first analyze the incident radar signal and determine what it is, pull characteristics of it out of memory, and then do some final processing to account for attenuation of the reflected wave, doppler effect and such (the time needed for these calculations are also precalculated and used for the final phase shift). Then you start transmitting. A proper radar return is sent back while the upfront analysis is being done but after that - practically nothing. And if it shows up for a frame or two it won't really matter.After the upfront work is done there won't be any leading edges to trigger on
                      But then that method will require your jammer to have perfect information of enemy radar. Not just their waveform or operating frequency range, but also exactly what frequency it will hop to at time t+1 aka the frequency hopping sequences and also the PRF jittering sequences, so kinda similar to what i said earlier about radar with constant characteristic (the difference is instead you know that radar well enough to know exactly what it will do at a given moment in future)

                      Comment

                      • TomcatViP
                        Rank 5 Registered User
                        • Nov 2011
                        • 6057

                        That's why I wrote long time ago that Active cancellation is the perfect tool to hack into civilian ATC and long time Friend airspace. It does not make any sense in military terms, relies heavily (understand on a very costly manner) on shadowy (privatized/deniable) intelligence and does not make much sense for an intermediary power like France (no persistence).
                        Last edited by TomcatViP; 7th January 2019, 10:33.

                        Comment

                        • eagle1
                          Rank 5 Registered User
                          • Feb 2011
                          • 1125

                          From aviation week :

                          (...) The upgrade will also see a series of improvements to Spectra. Developed by Thales and MBDA, Spectra is a fully automated system that provides electromagnetic detection, laser and missile warning, jamming and four chaff/flare dispensers. French industry sources say that during operations over Libya in 2011, Rafale literally disappeared from the radar screens of the Libyan air force, performing soft kills on enemy radar systems.

                          Bruno Carrara, director of the Rafale program at Thales, says the F3-R upgrade will involve a more advanced electromagnetic detection capability based on new digital wide-band-receiver technologies, improving the suites spectrum analysis as well as its instantaneous interception capability.

                          Thales will also update Spectras solid-state jamming subsystem, which was one of the first to use electronically steered phased-array antennas. Carrara says for F3R, Spectra will include more powerful antennas, while further increasing the power supply so that more threats can be jammed simultaneously. Like Saab, Thales will use GaN technology because of its power and efficiency.

                          Since the late 1990s, Spectras designers have dropped hints that the system can perform active cancellation receiving a radar signal and mimicking the aircrafts echo exactly one-half wavelength out of phase so the radar sees nothing.Carrara again implies that such a capability is in use:

                          There are other strategies, such as generating signals that will encompass or be higher than the echo from the aircraft, so that the radar threat will receive a signal that will mask the echo from the aircraft, Carrara says. Instead of creating a false echo and drawing the radar to the wrong place, the idea is to produce a signal that will mask the echo of the aircraft, so the radar will be unable to detect the aircraft Spectra is protecting.
                          Last edited by eagle1; 7th January 2019, 11:33.

                          Comment

                          • halloweene
                            Rank 5 Registered User
                            • Jan 2012
                            • 4342

                            Rafale F4 program will be officially launched tomossrow at Merignac (2 billion euros)

                            Comment

                            • TomcatViP
                              Rank 5 Registered User
                              • Nov 2011
                              • 6057

                              Meanwhile, Rafale's fans from the Runion island will be able to see two aircraft there next Monday. It will be also also the first time an A330MRTT will land on the island (next Tuesday)*

                              Lundi prochain, deux Rafale se poseront nouveau Gillot venant de Djibouti accompagns d'un C.135FR pour les ravitaillements en vol. Ils seront rejoints le lendemain par un Airbus A330 MRTT dont ce sera la premire escale runionnaise.
                              *Some event also with the demo pilot.
                              Last edited by TomcatViP; 13th January 2019, 20:07.

                              Comment

                              • eagle1
                                Rank 5 Registered User
                                • Feb 2011
                                • 1125

                                Rafale F4 is officialy "on" with 1,9 billion euros for its development. More than twice as much funding than for the F3R version.

                                58 rafales will be ordered in this latest standard in two tranches : 28 in 2022-2024 taht will incorporate as much F4 standard upgrade as possible and then a second tranche of 30 F4 rafales to be delivered up to 2030.

                                A big update in every field, including weapons : 1000Kg AASM, Mica NG, improved ASMP-A...

                                https://www.latribune.fr/entreprises...le-803742.html

                                "Ce standard F4 est un saut technologique, un saut industriel, un saut stratgique",

                                Rafale F4 full standard should be qualified in 2024 but some items will be available earlier. It is now the basis standard for futur export prospects like for Switzerland, UAE, or another Egyptian order.
                                Last edited by eagle1; 14th January 2019, 16:18.

                                Comment

                                • TomcatViP
                                  Rank 5 Registered User
                                  • Nov 2011
                                  • 6057

                                  Not exactly as depicted by eagle1.

                                  As I understand, if 1.9B have been credited for the standard F4, fully compatible airframe are expected to come out of the line in 2025. Before that, the remaining order from the Fr air force, 28 airframe will benefit from various level of implementation of F4 standard. Beyond that date, past 2025, Fr Air force might order some extra airframe (full complement expected b/w 2022/24).

                                  Export orders partially implemented with F4 upgrade mods* will be available for delivery (if ordered) b/w 2024/25. Then the opinion of the journalist writing the report is that Fr AdlA or the Fr navy might order some more (those will then be full F4 standardized airframe). This seems to be only his personal opinion as, if I must admit that I did not read the full MoD memo, he doesn't explicitly says that Miss Parly hasn't said otherwise:

                                  Originally posted by Fr MoD
                                  "Pour les livraisons venir, elles reprendront intensment en 2022, 23 et 24 et nombre des avions de cette tranche bnficieront d'amliorations du standard F4"
                                  -----------------------------------------

                                  "For future deliveries, they will resume intensely in 2022, 23 and 24 and many of the aircraft in this Tranche will benefit from improvements of the standard F4"

                                  *F4 modifications include some strategic systems that can't by definition be offered to third parties
                                  Last edited by TomcatViP; 14th January 2019, 21:39.

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                                  • eagle
                                    Rank 5 Registered User
                                    • Jan 2000
                                    • 2362

                                    58 rafales will be ordered in this latest standard in two tranches : 28 in 2022-2024 taht will incorporate as much F4 standard upgrade as possible and then a second tranche of 30 F4 rafales to be delivered up to 2030.
                                    To clarify, the 28 from the first tranche are already ordered. These not-full-F4-standard Rafales make up the not yet delivered rest of the 180 ordered so far. That means 152 Rafales delivered to French forces to date.
                                    The 30 newly ordered full standard F4 Rafales bring the total to 210.

                                    Any chance of additional orders beyond those 210? The 55 updated Mirage 2000D retiring in 2030 would leave only 210 combat aircraft, less than the target of 225. So maybe 15 more plus some attrition replacement. I guess any orders beyond that will depend on the progress of the NGF programme.
                                    How can less be more? It's impossible. More is more.
                                    Yngwie Malmsteen

                                    Comment

                                    • TomcatViP
                                      Rank 5 Registered User
                                      • Nov 2011
                                      • 6057

                                      To clarify the clarification, those famous 30s have not been ordered, yet. MoD stated that they will be ordered in 2023 (next gov).

                                      Originally posted by Fr MoD
                                      "D'ici fin 2024, 28 Rafale supplmentaires seront livrs et nous en commanderons 30 nouveaux en 2023", a-t-elle confirm.
                                      -------------------

                                      "By the end of 2024, 28 additional Rafale will be delivered* and we will order 30 new ones in 2023," she confirmed.

                                      *see my previous post
                                      Last edited by TomcatViP; 14th January 2019, 21:01.

                                      Comment

                                      • eagle1
                                        Rank 5 Registered User
                                        • Feb 2011
                                        • 1125

                                        According to le Figaro news paper (owned by Dassault) the F4 standard will also be deployed in the existing fleet :

                                        Dassault Aviation s'engage livrer le Rafale au standard F4 en deux tapes, en 2022 et 2024. Le standard sera aussi dploy au sein de la flotte en service.
                                        http://www.lefigaro.fr/societes/2019...-du-rafale.php

                                        Comment

                                        • TomcatViP
                                          Rank 5 Registered User
                                          • Nov 2011
                                          • 6057

                                          Comment

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