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garryA

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Viewing 15 posts - 661 through 675 (of 948 total)
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  • in reply to: If you had to choose between Rafale or F-35 #2131838
    garryA
    Participant

    No you don’t need something like SBX-1 at all.

    http://www.ausairpower.net/APA-HQ-7-Crotale.html

    Crotale work at very high frequency though, I am under the impression that we are discussing X-band fighter radar.

    In a nutshell, as the radar is scanning, very rapidly in case of AESA, it will receive a reflection at several beam positions, as well as obtaining an accurate velocity, it can therefore calculate that the object lies in the centre of this range. RWR has no such ability.

    Actually , I was talking strictly about angle tracking , about range tracking radar is simply much more superior both in speed and accuracy

    in reply to: If you had to choose between Rafale or F-35 #2131846
    garryA
    Participant

    Some facts:
    Interferometric receivers (that are only fitted in US & French types although they’re an option on the Gripen NG) can determine angle of arrival with an accuracy of ~1° at 1GHz and ~0.1° at 10GHz.
    Spiral antenna-based RWR have typically 5-10x less resolution than an interferometric one.
    A parabolic antenna has a beamwidth (in degree) of 70*lambda/D where lambda is the wavelength and D the antenna diameter.
    So taking as example the Typhoon radar which operates at 10GHz and has a diameter of 70cm, its resolution is at best… 3×3 degrees.
    AESA are a tad better, with an extra 10dB of gain you can expect resolution of around 1×1° (useless for scanning but intersting if you already know where your prey is thanks to another source. It’s also nice for SAR modes to achieve sub-metric resolutions).
    .

    1-The high accuracy of interferometry is based on the assumption that the signal comming at 2 antenna is from a single source , if there is more than 1 source then the effect would be similar to an antenna with very wide beamwidth but the different is the beamwidth size here not depending on the RWR
    2-Radar resolution when scanning and tracking is not the same , there are dozen of methods to improve resolution of radar once its target is detected that will allow angular resolution in order of 1/10 beamwidth, take for example : conical scanning radar employs a beam of radar energy that is continuously rotated around the target. This circular rotation of a pencil beam generates a cone-shaped scan pattern with the apex of the cone located at the antenna. .As the radar beam rotates around the target, the circular scan patterns overlap in the centre. This creates a central tracking area that has a much smaller effective beamwidth than the rotating radar beam
    https://basicsaboutaerodynamicsandavionics.files.wordpress.com/2016/04/conical-scan.png?w=1200
    another common one is monopulse configuration where the radar generated 4 beams with target at the center
    https://basicsaboutaerodynamicsandavionics.files.wordpress.com/2016/04/monopulse-radar12.png?w=1200

    SNR requirements for Radar, to filter our in its purest form specific return signal , and enable TOA and Doppler shift measurements , is nowhere relevant or indicative for the need for direction finding an emission.

    Actually SNR is very important for interferometry

    garryA
    Participant

    BLC, the F-22, YF-23 also have this as well. Venting above and behind the inlet.

    What is BCL?, F-35 has none, i wonder why

    garryA
    Participant

    Why JF-17 DSI has holes on them?
    https://thelexicans.files.wordpress.com/2013/12/jf17_thunder_dsi_intake_01.jpg

    garryA
    Participant

    Depends on L/D.
    I’ve already posted dynamic thrust graphs for RD-33 on MiG-29. RD-33 produce 10250kg thrust at M0,9 S/L to achieve 345 m/s climb rate. What is the thrust of EJ-200 at those conditions? “Only” 9000kg?

    I was thinking about this for a bit, since we know Typhoon can fly supersonic on dry thrust while Mig-29 cant, shouldn’t that translate to either less drag or better dynamic dry thrust on supersonic regime?

    garryA
    Participant

    Anyway, while you 2 are at it, how are J-10 and JF-17 compare to F-16? Pressure recovery wise what are the advantages, disadvantages of DSI compare to plate inlet like on Typhoon, Rafale?

    https://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Pakistan_airforce_FC-1_Xiao_Long.jpg/800px-Pakistan_airforce_FC-1_Xiao_Long.jpg
    https://s-media-cache-ak0.pinimg.com/originals/f1/ce/41/f1ce41906033d7e22a6b9ef4818c0915.jpg

    garryA
    Participant

    I understand that every design is a matter of trade off but what part of the envelope the Typhoon actually optimized for?
    Compare to Mig-29

    The canard of Typhoon is above the wing so it isn’t optimized for subsonic sustain turn rate, while Mig-29 has LERX to aid its subsonic turning capabilities

    On the otherhand, Typhoon lack variable inlet, while Mig-29 has one, so that will also improve Mig-29 dynamic T/W ratio at supersonic compared to Typhoon.
    Neither, Typhoon or Mig-29 is intended to be VLO or StoVL or Carrier capable so no trade off there
    So if we follow this way of logic, Mig-29 just seem to be a superior design to Typhoon ??, it doesn’t make sense to me that a design 10-15 years later cant atleast match the earlier one ( given that there is no particular trade off that Typhoon needs while Mig-29 doesn’t )

    garryA
    Participant

    Grew the **** up. CG shift can be compensated by a few cm, nothing more. Remove such heavy equipment and aircraft won’t even take off and fly in level, let alone perform agility demonstrations at airshows.

    I dont think they removed equipments from Su-27 in airshow but didn’t they removed radar , electronics equipment ..etc from the Su-27 to make P-42 ? seem to fly alright

    in reply to: If you had to choose between Rafale or F-35 #2132567
    garryA
    Participant

    Number of elements in the phase measurement context will not significantly improve accuracy overall. It will only result in averaging the same incertitude level per elements over a greater number. By virtue of statistical distribution it could potentially give a slightly better average compared to averaging on a lesser count. In no way , this would be any significant in magnitude.
    For distance across elements to improve AOA accuracy, it depends on the interferometer architecture designed to achieve the ambitioned accuracy.
    So comparatively to Radar (AESA, using phase interferometry too ) we are talking same magnitude of accuracy in bearing measurement. Main advantage of radar being to be specifically tuned to its range of frequencies where it will yields most accurate results.

    Radar in a monopulse configuration can transmit 4 parallel beams to determine target angular direction with much higher accuracy
    https://basicsaboutaerodynamicsandavionics.files.wordpress.com/2016/04/monopulse-radar.png?w=1200
    Because the beams are parallel ,if the target is at the centre ,the radar reflection will arrive at the 2 antennas at the same time and has the same phase.On the other hand, if the target is at an angle to the bore sight then the radar reflection will arrive at one antenna later than the other.By contrast, RWR will have to rely on a single beam .Moreover ,for interferormetry angular measurement of RWR , the system need to assume that the pulse received at interferometer came from the same source, so if the signal come from 2 different sources then accuracy will be reduced significantly

    Any way achieving 0.1 deg accuracy, not unheard of for interferometry is on par with radar , as expected.

    AFAIK, the accuracy is on order of 1-2 degrees ( ALQ-218 and ALR-94)

    in reply to: Russia moving tac air troops to Syria #2132569
    garryA
    Participant

    Not too familiar with sputnik ..

    russia24 and news front and rt all reporting same story, just checked this sputnik thing – its not on there

    Now i dont speak Russian so i dont know what exactly said in the video .However ,isnt it very hypocrite of you to take everything said by the Russian side as fact while at the sametime consider all information from western side as fake ? .Why cant you keep the same skeptical attitude regarding both case ?

    in reply to: Russia moving tac air troops to Syria #2132571
    garryA
    Participant

    The hundreds of millions of dollars allocated to the “moderate” terrorists that have to be accounted for to Congress (the money the Saudis and Qataris don’t have to be accounted for to anyone because they are not democracies and their rulers dip into public funds like it’s their own money because they are absolute rulers accountable to no one)

    Why don’t you spend a few seconds googling Senate Armed Forces and Foreign Affairs Committee hearings in the past few months and find out yourself the recent video of the general telling the Senate hearings when asked how many good rebels the US had trained with all that money……the answer was 4 or 5! 😀 (because all the rest had defected to the “bad” ISIS terrorists (together with all of their weapons :D).

    The burden of proof is on the person who made the claim , you claimed US fund ISIS then it is your responsibility to provide evidence to support that point , not me. Please find the specific video and the time in the video that those information you claim was mentioned

    Garry, I am a disappointed that you did not answer my answer to your question and cut out the important bit….for the benefit of everyone else I’ll remind you what you said :D.
    and my answer was:

    So there was a video of some rebels yelling at US troops and that is your evidence for the claim ” US fund ISIS” ?????

    The Syrians are flying what they have for their current needs for daytime fighting….no doubt the Russians will help replace some of the antique early versions at some point in the future.

    I dont see the consistency in your logic, you concluded that US funded ( money , weapons ..etc ) ISIS to fight Assad , no evidence provided but at the same time believe that Russian doesn’t do support their ally ?

    By the way, why do you keep going on about me having a problem with you asking things? It’s actually the complete opposite! 😀 I want you to ask as many questions as you like…..ask what you like about what you like because we are here on this forum to find out more about aviation and improve our knowledge ;- )

    Because when i ask the question , you accused me of sneaky link Syrian and Russian with the attack , accused me of being a shill ..etc , just because you put the word “joke” at the end of the sentence doesn’t you are not actively trying to silent people with different opinions by accuse them of being a government paid troll.

    Ask the Chairman of the Joint Chief of Staffs where in Syria he thinks the video of the Americans being jeered by the jihadists above was taken!

    (in the Senate hearings on Thursday he was asked specifically about this video).

    Put the video up here and specific the time when he answer that question then we talk.

    The point is there is no conclusive evidence this was an air attack rather than by proxies with a ground attack using artillery or mortars.

    Also, some of the pictures of the damaged trucks appear to be of rust buckets that could have been taken at another date and place and mixed up with some of the picture…..the point is there is no conclusive evidence that either the Syrians or Russians attacked the aid convoy……in contrast to the US bombing of the Syrian positions that allowed ISIS to advance and which belatedly admitted by the Americans after first denying outright they did….no apology to the Syrian government they killed so many government troops and allowed ISIS to prosper (reason is they are illegally trying to overthrow the Syrian government).

    is there any conclusive evidence that the attack made by US wasnt a mistake in IFF ? is there any conclusive evidence that the attack wasnt another collateral damage case ? , is there any conclusive evidence that the attack was made to allow ISIS to advance ? the answer to all of that is also no , but i see you have no problem making accusation when it is the western side doing wrong.

    in reply to: If you had to choose between Rafale or F-35 #2133284
    garryA
    Participant

    @ Garry, regarding your first question on your last post:

    The precision is independent of the distance. Hence when evaluating a closer signal return, the inaccuracy will be relatively higher in percentage than for a farther one (sin, cos and tan are evaluated distance).

    Let say if the angular accuracy is 1 degree , shouldn’t the aquisition box get bigger over long distance ?
    For example
    :
    http://www.ausairpower.net/XIMG/64N6E-vs-Nebo-SVU-Boxes-2.png

    in reply to: Russia moving tac air troops to Syria #2133298
    garryA
    Participant

    Fresh off the news:
    things are clearing up as to what happened when US and their allies bombed syrian soldiers.

    1. 2 predators and 1 other unidentified drone were monitoring the SAA positions for 2 full days
    2. on the 3rd day all the man made fortifications were bombed, a10’s followed up by destroying 2 t72’s, 1 t-55, a mobile AA battery, and other weapons
    3. when the SAA started to retreat via foot, the 2 predator drones engaged via hellfire missiles
    4. after an hour long bombing isis got a radio transmission that ” the friendlies cleared the area, move in now, backup is on the way” RU radio counter intelligence fixated messages from “isis” friends that were coordinating isis counter attack while the predators were still watching…

    Did you get that from Sputnik ?

    in reply to: Russia moving tac air troops to Syria #2133341
    garryA
    Participant

    Good post.

    The Syrians and Russians have never attacked an aid convoy before….so why this one?

    The aid convoy was in an area controlled by the “moderate” terrorists and if the Syrians or Russians did the attack I agree what would they gain other than draw attention away from the earlier American “accidental” attack on the Syrian positions that allowed ISIS to advance?

    No one said they intentionally attack an UN convoy , but in any war , mistake happen.Could either be wrongly identify or colletaral damage

    in reply to: Russia moving tac air troops to Syria #2133345
    garryA
    Participant

    Lol 😀 ISIS are cannon fodder and unwitting proxies because someone is out to get Bashar Assad……getting rid of Assad is illegal under international law by the way in exactly the same way would getting rid of the President of the US or the Prime Minister of the UK by the same means would also be illegal……illegally trying to “do a Gaddafi” (that turned out well in Libya didn’t it…now full of Jihadists and country up the spout with thousands of refugees trying to get to Europe) to the head of state of a sovereign country or head of government recognised by the UN is wrong whoever would does this crime under international law.

    …..imagine anyone trying to do the same thing in the USA, UK or France….it would be wrong here and it’s wrong in Syria whoever does it…..anything that can damage the Assad regime, including aiding ISIS and the jihadists (because they are the ones doing the actual fighting as cannon fodder against the Syrian government) is being done by American, British and French special forces currently present, also illegally, in Syria.

    You are keep putting the syrian rebel and ISIS in the same group , but they are not , they are even fighting each other
    ISIS came from a branch of Al qaeda, while the Syrian rebel form ways before that when Assad use weapons again protesters

    😀 the “moderate” terrorists are ISIS and Al Nusra…all of them are Jihadists and they have dozens of other names ….they keep changing names every time one of them are exposed…..but it’s the same lot! They change names, from e.g. Nusra to whatever name they change to today to try and shake off the scent of ISIS and Al Qaeda but they are what they are! Memories are short but Al Qaeda did 9/11….Al Nusra (or whaterver name they use today) and the jihadists are their affiliates of Al Qaeda and support 9/11 and hate the USA but I suppose the enemy (ISIS) of my enemy (Bashar Assad) is my friend (ISIS)….very sad and cynical because a whole country, cultured compared to the Wahabbi kingdoms, has been destroyed all in pursuit of the aims of whoever said get Assad. .

    No they are not the same group , just because they use guerrilla warfare doesnt mean they are the same , try again. Following your logic we would have concluded that Kurd , Hezbollard ,Al qaeda and ISIS are all single group

    This dirty war would stop fairly quickly….with no more refuges……if the US and Saudi stopped supplying and supporting “moderate” terrorists (ISIS and Nusra and thirty other similar groups paid and trained in camps in Jordan, Turkey, East European countries, all paid for by Saudi, Qatar and the US (as stated in congress)..

    When did congress said they trained the ISIS ?

    Also I said nothing about you being a shill….have I touched a nerve? To me it is odd what you and your “team” (joke) post, but please carry on and everyone can decide for themselves what they think….after all we are not communists! (copyright The Godfather 😉

    So it is only not odd if i have sketical attitude about every positive new about the West and eat up all negative news about US without question like you and Crowd ?

    Here is a video of the poor American FACs being jeered out of a town in Northern Syria called Al Bab by the jihadists they are forced to help 😉 I feel for these American soldiers because they know these are nasty jihadists they are forced to provide secret assistance to and they know these jihadists support 9/11 so why is the US providing these same jihadists with air and other support just to illegally overthrow the sovereign government of Bashar Assad?

    Take a good look at the “moderate” terrorists….this is what they look like…..this is the video that Gen Dunford (Chairman of Joint Chief of Staffs) said in Congress last Thursday that he knew about, but said he hadn’t watched and anyway it didn’t matter because they were doing a good job! 😀

    What do you expect a rebel group to look like ?

    Garry mate you ask away as many questions to your heart’s content about the non-existent night fighting capabilities of the Syrian air force! This is an aviation forum where we discuss these kind of things and I encourage you to ask as many questions as you like because then the many well informed people on this aviation forum with their specialised knowledge can put us all right, unlike can be done on say the Daily Mail website or by that comic newspaper The Sun (owned by Rupert Murdoch who also owns Fox News!).

    I pointed out you were going on and on and on about this, only because you were trying to link this a video from the discredited “white helmets” (jihadists wearing white helmets pretending to be the good guys but actually nothing to do with the official Red Cross) saying it was Syrians helicopters dropping barrel bombs (no proof in the video of helicopters hovering and no way they could have seen barrel bombs or the helicopters in the pitch dark with no lights) when the Syrian helicopters do not have even primitive night fighting capability.

    Your suggestion that could use a make-shift night fighting capability using night vision goggles was nicely refuted by MSphere because they wouldn’t work through the glass! And the Syrian can’t carry out the work (not in the field and they don’t even have the resources) required to convert their ancient machines with night fighting capability and all of this was outlined in detail by MSphere in the posts above.

    I was arguing with crow about that , and i did stated my position at the start too , iam not sneaky link the 2 at all ,the offical news was that US blame Syrian and Russian for the attack , crowd said Syrian doesnt have night fighting capabilities , and i was argue about that , what exactly is your problem ? or do i have to take his words for it ?
    Now about the resouces required to make modification , isnt it so ironic that you are so easily to believe US funding ISIS without needing any evidence , but at the sametime think Russian doesnt help Assad army at all eventhough they are in the same side ?

    The point is the aid convoy could have attacked as Marcellogo says by mortars or artillery operated by the jihadists…..so there is no conclusive proof either way.

    So you think the Jihadist towed the mortal along the convoy to attack it ???

    Case 5 as pointed out by Marcellogo is it was a surface-to-surface attack by mortars or artillery ….which both sides have (jihadists and the Syrian government) can there is no conclusive proof either way.

    I never refute this point

    The video posted by TEEJ purporting to be of the attack on the aid convoy is of short duration, does not have proof of where or when it was taken….and show no planes…..

    Interesting that you would say that , isnt that kinda the same for all video that has been posted ? you cant be sure about exactly where or when exactly they was taken either

    There are no huge bomb craters seen in the pictures of the aftermath as are seen in real bombings by Russian Su-24s dropping a few tons of bombs…..the cardboard boxes aren’t even burnt when a the blast from 100 kg or 250kg bombs would have can be more devastating than say a much smaller artillery or mortar shell.

    That depend on whether the bomb is air detonate or not , then there is also others factors like size and distance

Viewing 15 posts - 661 through 675 (of 948 total)