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    Austin

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    Re: General Questions Thread:

    Post  Austin on Mon Dec 26, 2011 1:31 pm

    Garry , I understand what you are trying to say.

    I have rarely seen radar designed in more than one band and i am talking of more capable bigger radar , the missile has small radar with limited power and processing capability.

    Having a dual band X/Ku for that seeker is impossible , I suspect it rather a X band radar or Ku band one of both depending if its talking of IEEE or NATO frequency.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Mon Dec 26, 2011 10:05 pm

    Garry , I understand what you are trying to say.

    With respect Austin... I don't think you do.

    Designers don't just choose a radar frequency for fun.
    Specific frequencies have different properties which leads to different advantages and disadvantages.

    If you want to spot objects on the ground then a very high frequency radar can give an almost photo like view of things like terrain... that is why we get such a detailed view of the world, but the cost is processing power. Flash still images in front of a human at the pathetically slow rate of 25 frames per second and we think we are seeing normal live moving action... when in fact we are seeing still images flashed before our eyes at a rate of 25 frames per second.

    If you just want to detect the presence of a target then a long wave radar will ignore clouds and shaping of the object.

    Different frequencies have different performances in different conditions, so looking down yo might find changing frequency gives you better performance, while looking up a different frequency again might be better.

    The point is that the missiles seeker in an Active Radar Homing missile is a transmitter and receiver so it can choose the frequency to transmit... the fact that it can transmit, means it can also receive it, so it sends a pulse and listens for the signals it gets in return... using doppler shift (which is a property of the returning wave) it can separate moving objects from those that are still in comparison with their background).

    I have rarely seen radar designed in more than one band and i am talking of more capable bigger radar , the missile has small radar with limited power and processing capability.

    Size of the radar, processing power, and level of power have nothing to do with it. A transistor radio can detect several bands at once, in fact I have a short wave radio that can detect AM frequency radio waves from 530KHz to 1600KHz, plus short wave 1 from 2.3 MHz to 7 MHz, and Short Wave 2 from 7 MHz to 22MHz.

    In the case of a radio it only receives and does not transmit... in the case of this ARH missile its antenna both transmits and receives.

    The radio and Radar bands are not based on antenna capabilities.

    The radio transmitter for the Shturm and ATAKA missile operates in the 35GHz range which is high K or Ka band... and a very similar frequency to speed camera radar... very hard to jam.

    What makes it so impossible?

    Having a single radar antenna that can transmit and receive HF (10-100m wavelength) and MMW radar (7.5mm to 0.1mm wavelength) would be near impossible.

    Having a single antenna that can transmit and receive X (25mm-37.5mm wavelength) and Ka (16.7mm-25mm wavelength) Band radar signals is not that big a deal!

    Processing and power and radar size doesn't come in to it.. basically a radar that can operate in frequency ranges of 20mm to 30mm... which is a pathetic 1cm range of bandwidth is technically an X/Ku band radar. In fact a radar antenna designed to operate in the 24-26mm range is technically an X/Ku band radar... how can a radar with a 2mm bandwidth be impossible to make?

    Austin

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    Re: General Questions Thread:

    Post  Austin on Tue Dec 27, 2011 6:58 am

    I was talking to a friend on this , he was saying this could be either Ku or X band seeker , which means option for both of those and not a dual band one.

    Its really not easy to get a dual band seeker design and fit in missile cone , its expensive and secondly the power requirement and hardware is different.

    Its easy to have multiband passive seeker or receiver , but a dual band active seeker is a very tough ask and almost impossible.

    Even the latest meteor seeker operates in single J band.

    Actually multiband seeker is quite common in ARH missile like latest KH-31P
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Tue Dec 27, 2011 10:43 am

    Its really not easy to get a dual band seeker design and fit in missile cone , its expensive and secondly the power requirement and hardware is different.

    What are you talking about????

    Are TVs expensive because they cover VHF and UHF channels/bands?

    Is my AM FM radio expensive because it covers 4 bands?

    Its easy to have multiband passive seeker or receiver , but a dual band active seeker is a very tough ask and almost impossible.

    It is easy now with digital electronics... with old hard wired stuff the Kh-25MP came with different seeker heads designed to detect different signals. The Kh-58 was the same.

    The newer models have multi band seekers and are fully digital.

    Even the latest meteor seeker operates in single J band.

    AUSTIN... listen to me. METEOR operates in one band because the designers have decided it can perform its mission best using that frequency range. If they wanted it to do other things that required it to hit different targets and therefore require different capabilities they might have designed it to either operate in a different frequency range or several different frequencies.

    Multiband seekers in ARMs are to allow the ARMs to be used against a wide range of targets emitting different signals in different bands.

    A missile with a seeker optimised for the X band will not be able to detect signals in different frequency ranges.
    A broad band seeker can detect signals in a wide range of bands.

    An AAM is designed for a specific mission against specific targets for which only a very few frequencies will be of use.

    There is a huge disadvantage to putting a broad band seeker on an AAM because it will mean the antenna will be picking up all sorts of noise and rubbish that have nothing to do with its mission.

    Very simply Austin, with modern digital electronics and antenna design the R-77 can operate in two very close together bands.

    The only reason for having a seeker in each band is for a specific target, so by having two separate seekers you are saying you can only engage this sort of target and not the target the other seeker can engage well.

    If there were two seekers... on in X band and one in Ku band why does the photo say "Seeker to fit RVV-AE missile" instead of seekers. Also why is the 350mm calibre missile seeker next to it given a single designation if it is one of two?


    Austin

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    Re: General Questions Thread:

    Post  Austin on Tue Dec 27, 2011 11:07 am

    GARRY , I hope you are not confusing by giving me example of your radio and TV since they receive AM or FM or other bands , those devices are receiver of frequency and not transmittor of those frequency.

    Can you provide me a better source for RVV-AE having dual band seekers ?

    I think there are option provided , the older seeker in BVR used to operate in X band and now they are in J band or K ( Ka or Ku ) , the latter has better burn through capability and difficult to jam and can give better reslution of target although short on range.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Tue Dec 27, 2011 12:19 pm

    GARRY , I hope you are not confusing by giving me example of your radio and TV since they receive AM or FM or other bands , those devices are receiver of frequency and not transmittor of those frequency.

    And to receive those frequencies they need an antenna that detects such frequencies. All they need to be a radar is a transmitter... and of course to operate in radar frequency bands.

    Most modern radars have transmit/receive modules/antennas/elements that can both transmit and receive signals.

    I think there are option provided , the older seeker in BVR used to operate in X band and now they are in J band or K ( Ka or Ku ) , the latter has better burn through capability and difficult to jam and can give better reslution of target although short on range.

    Then it would show two models of the seeker... one with Ku and one with X band seekers. Note also in the photo you posted it credited two seekers with dual band capability... the RVV-AE and a 350mm calibre seeker too... likely the R-37M/RVV-BD.

    Considering X band radars are common in fighter aircraft is it not rather likely the X band component might just be a passive seeker like the R-27P and R-27EP?

    The Active homing radar transmitter being a Ku band transmitter with an X band and Ku band antenna to operate in X band passively and in Ku band in active homing mode.

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    Re: General Questions Thread:

    Post  Austin on Tue Dec 27, 2011 12:57 pm

    GarryB wrote:And to receive those frequencies they need an antenna that detects such frequencies. All they need to be a radar is a transmitter... and of course to operate in radar frequency bands.

    Its not that hard to design a passive receive only multiband antenna compared to active multi band antenna.

    Even wondered why even modern AESA or PESA radar of ground based type are just single band , I know of only SPY-3 which is multi band , think its X and S band.

    Most modern radars have transmit/receive modules/antennas/elements that can both transmit and receive signals.

    The hardware requirenment for a dual band active X and Ku band is very complicated and to fit in small nose of missile is much more.

    I think there are option provided , the older seeker in BVR used to operate in X band and now they are in J band or K ( Ka or Ku ) , the latter has better burn through capability and difficult to jam and can give better reslution of target although short on range.

    Probably its possible the X band could be passive or datalink and the ARH are of Ku band type or X band is of monopulse type.

    I have yet to see any reference of R-77 having dual band capability , even Agat on its official website does not claim so.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Tue Dec 27, 2011 11:28 pm

    Form follows function.

    Put a radar on a ship that is for detection of rain and storms and it is a weather radar. Such a radar you will want it to detect moisture in the air... in the form of clouds and rain and other forms of precipitation.

    You need to be able to see the weather at all times to be able to sail around it, or the worst of it.

    The problem is that radar in that frequency becomes less useful when navigating congested waters in bad weather... you want to see other vessels... bits of land poking up out of the water, and even bouys and people in the water in any weather, day and night.

    The result is that the weather radar operates at a frequency where moisture seriously effects the radar beams... by reflecting them, and that the collision avoidance radar passes straight through water and moisture in the air and only reflects off much more solid things like ships and Islands.

    Most fighter jets are not interested in weather and have their radars optimised to detect hard things.
    There would be no advantage to being able to transmit or recieve in HF using a fighters primary sensor as he will have an onboard radar for that.

    EM bands are not arbitrary, they relate to useful wavelengths for specific purposes. Even in the IR spectrum there are specific bands that are used in sensors and each of the three bands (called short, medium and long) have advantages and disadvantages. The frequencies between these three bands are not used because these frequencies are absorbed by moisture or dust in the atmosphere and have a very limited range.

    The reason most radars don't operate in multiple bands is because their purpose and function doesn't require it.

    For bands that are completely different like VHF and X band there are enormous problems because the antenna size is so different. For bands that are close together however it is much easier to design a transmitter and receiver that would be suitable.

    You also need to keep in mind that just because a radar operates in the X band or Ku band doesn't mean it can transmit and detect any frequency in that band range.

    Equally different sources have different offical band ranges so you need to be clear which system you are using.

    I have yet to see any reference of R-77 having dual band capability , even Agat on its official website does not claim so.

    You posted the specs sheet yourself....
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Tue Dec 27, 2011 11:39 pm


    Probably its possible the X band could be passive or datalink and the ARH are of Ku band type or X band is of monopulse type.

    Most datalinks are not in the X band range... the datalink for the ATAKA/Shturm ATGM for instance is 35GHz...

    Frequency and Wavelength ... Radio Band designation

    30-300 Hz 10-1Mm .....ELF (extremely low frequency)
    300-3000 Hz .........................................1Mm-100 km
    3-30 kHz 100-10 km ...........VLF (very low frequency)
    30-300 kHz 10-1 km .....................LF (low frequency)
    300-3000 kHz 1 km-100 m ....MF (medium frequency)
    3-30 MHz 100-10 m ....................HF (high frequency)
    30-300 MHz 10-1 m ..........VHF (very high frequency)
    300-3000 MHz 1 m-10 cm ..UHF (ultra high frequency)
    3-30 GHz 10-1 cm .............SHF (super high frequency)
    30-300 GHz 1 cm-1 mm EHF(extremely high frequency)
    300-3000 GHz 1mm-100$\mu m

    Frequency and Wavelength of the IEEE Radar Band designation

    1-2 GHz 30-15 cm .................L Band
    2-4 GHz 15-7.5 cm ................S Band
    4-8 GHz 7.5-3.75 cm .............C Band
    8-12 GHz 3.75-2.50 cm......... X Band
    12-18 GHz 2.5-1.67 cm .......Ku Band
    18-27 GHz 1.67-1.11 cm .......K Band
    27-40 GHz 1.11 cm-7.5 mm .Ka Band
    40-300 GHz 7.5-1.0 mm mm

    source: http://www.naval.com/radio-bands.htm

    Which as you can see above under radio wave is in the EHF band, and would be in the Ka band if it was a radar.

    The Arbalet radar for the Ka-52 is a dual band radar that operates in both Ka and L band, which as you can read above means 1-2 GHz and 27-40GHz... which I think you will agree is a little harder than operating in two bands that are so close together like X and Ku bands.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Sun Jan 01, 2012 6:58 am

    Having another look at the initial image with the radar seekers have you noticed that the of the 5 seekers listed, the first is 20cm in diameter, the second is 35cm in diameter, the third which is active mmw radar is 15cm calibre, while the remaining two seekers are both 20cm.

    The guidance is active radar (X/Ku band), active radar (X/Ku band), Active MMW Radar homing (Ka band), and the second last is semi active AND active Ku band homing, and Active and Passive Ku band homing.

    Each of those terms has a specific meaning... Active radar means the radar in the seeker emits and receives radar energy and requires no other info source, though it can be updated with a datalink.
    Semi active radar homing means the seeker in the missile just listens for reflected energy and some other source marks the target... the other source could be another aircraft including fighters and AWACS platforms... in theory even a ground based radar could mark the target.
    Passive radar homing means the missile detects and seeks target radars that emit radar energy to find targets.

    To me this suggests the first seeker is the RVV-AE ARH missile seeker, the second is the active radar homing seeker for the R-37M or RVV-BD long range missile. The third seeker is an active MMW radar seeker with a diameter of 150mm... now that could be for the SA-8 which has a similar calibre, but I suspect it might be for a new model ATGM... at 8kgs it would be too heavy for Kornet, and at 150mm it is too big for Hermes which is 130mm calibre, so I suspect it might be for a new model fire and forget Krisantema, perhaps with a 152mm calibre HEAT warhead.

    The last two seekers could be the domestic active radar homing seekers for the R-77 family of weapons... both have active radar homing, while one also has anti radiation capability... which would be ideal for Su-34s, and the other has SARH capability which would be useful on Mig-31s against low flying stealthy cruise missiles, or perhaps by the Mig-29K for use over large bodies of water where doppler shift is not so effective because the whole sea is moving.

    Note that if the X/Ku designation referred to two different seekers, why not display them separately like the last two missiles which share the same data except for guidance (ie SARH/ARH, ARH/ARM).

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    Re: General Questions Thread:

    Post  Austin on Sun Jan 01, 2012 8:24 am

    GarryB wrote:Note that if the X/Ku designation referred to two different seekers, why not display them separately like the last two missiles which share the same data except for guidance (ie SARH/ARH, ARH/ARM).

    Garry the jury is out on the dual guidance mode , i think its Ku guidance or either X guidance , I have yet to read any thing on R-77 that says its dual guidance , not even its manufacturer says that.

    So i will reserve my judgement unless i find something or unless you find something that says that explicitly.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Sun Jan 01, 2012 12:21 pm

    But technically it is not dual guidance... dual guidance would be a combined IR and Radar seeker.

    This is merely a guidance system that combines two radar bands.

    We know it is an active radar seeker, and we know it has a home on jam function.

    Personally I think it is an active radar homer in Ku band, but with an antenna that can detect signals in two bands... Ku and X, that would make it an active Ku band missile with ARM capacity against X band jammers.

    On this website:

    http://www.radartutorial.eu/07.waves/wa04.en.html

    They lump X and Ku band radars together:

    I/J- Band (X- and Ku- Band Radars)

    In this frequency-band (8 to 12 GHz) the relationship between used wave length and size of the antenna is considerably better than in lower frequency-bands. The I/J- Band is a relatively popular radar band for military applications like airborne radars for performing the roles of interceptor, fighter, and attack of enemy fighters and of ground targets. A very small antenna size provides a good performance. Missile guidance systems at I/J- band are of a convenient size and are, therefore, of interest for applications where mobility and light weight are important and very long range is not a major requirement.

    This frequency band is wide used for maritime civil and military navigation radars. Very small and cheap antennas with a high rotation speed are adequate for a fair maximum range and a good accuracy. Slotted waveguide and small patch antennas are used as radar antenna, under a protective radome mostly.

    This frequency band is also popular for spaceborne or airborne imaging radars based on Synthetic Aperture Radar (SAR) both for military electronic intelligence and civil geographic mapping. A special Inverse Synthetic Aperture Radar (ISAR) is in use as a maritime airborne instrument of pollution control.

    Hmmm, very small and cheap antennas with fair range and good accuracy... might be useful in an ARH missile?


    BTW I know Wiki isn't the best source, but
    CATIC is known to be developing X-band and Ku-band active radar seekers, which may be intended for the PL-12. However the latest reports confirm that China has been co-operating closely with Russia's AGAT Research Institute, based in Moscow, and that AGAT is the source of the PL-12's essential active seeker. This joint development effort (perhaps with the name 'Project 129') has reportedly seen the supply of AGAT's 9B-1348 active-radar seeker (developed for the Vympel R-77, AA-12 'Adder') to China for integration with the Chinese-developed missile. Alternatively, technology from AGAT's 9B-1103M seeker family may be offered to China. Russia is also the source for the missile's inertial navigation system and datalink.

    Finally, the PL-12 has a 'home-on-jam' mode that allows it to passively track and engage an emitting target, without ever using its own active radar or a radar from the launch aircraft. This capability is the foundation on which the capability of anti-radiation missile is developed. The seeker is connected to a digital flight control system that uses signal processing techniques to track a target.

    It has R-77s seeker and a HOJ capability...

    http://en.wikipedia.org/wiki/PL-12

    Also, while looking I found this:

    The Agat Moscow Research Institute is developing an upgrade of its active seeker for medium range air-to-air missiles. At the same time Russian radar house Phazotron is preparing to test new long range phased array radars.

    Agat's 9B-1103M active radar seeker will have a 25km (13.5nm) acquisition range against 5m² (54ft²) radar cross section - or fighter-sized - targets.

    Iosiph Akopyan, Agat general designer and director, says the use of fibre-optic rotation sensors (FORS)in place of inertial gyros will give the seeker an almost instantaneous readiness capability. Akopyan says Agat is developing the seeker as a private venture and that it can be installed on any air-to-air missile with a 200mm (7.8in) diameter body including the Vympel R-77 (AA-12 Adder/RVV-AE). Laboratory testing continues on components and a seeker prototype will be ready for integration by mid-2000.

    Akopyan says a family of active seekers for air-to-air and surface-to-air missiles can be developed using FORS. He says 200mm, 330mm and 450-500mm diameter seekers could cover the range of missile requirements. FORS sensors are produced by Moscow-based Fizoptika and cost about $2,000 each, Agat says equivalent performance laser gyros cost $25,000.

    The upgraded 9B-1103M also uses a new digital processor for signal and data processing. At 10kg (22lb), the seeker is 6kg lighter than the R-77's 9B-1348E which has a 16km acquisition range. Akopyan says that Agat is looking for international partners to develop the seeker.

    Note all the missiles in your picture were 9B-1103Ms with different body diameters, so likely all have digital signal processors. That tells me the RVV-AE for export model is probably the same as the seeker sold to China for their PL-12 missile.



    More info here too:

    http://defenceforumindia.com/indian-army/7784-agat-radar-seeker-makers.html

    But how about this:

    http://www.ausairpower.net/APA-Engagement-Fire-Control.html

    Scroll down to near the bottom where there is a title: Phazotron 1L36E/1RS2 / VNIIRT 1RS2-1 / 96K6 Pantsir S1 / SA-22.

    Below that title is a large photo of a Pantsir-S1, and then a lot of text, and then a RCS to radar range chart and then a large photo of the early round parabolic yellow tracking radar on the old model Pantsir.
    Beneath it it says:

    The 1L36-01 Roman was the first engagement radar used on the Pantsir S demonstrators. The characteristic conical radome shape conceals a parabolic reflector antenna with a quad waveguide feed for dual plane monpulse angle tracking, with X-band and Ku-band channels. Note the smaller upper missile command link antenna. The radar has been labelled as a 96L6-1, but more commonly as the 1L36-01 (© 2007, Yevgeniy Yerokhin, Missiles.ru).


    Scroll down further and each iteration of the system has a similar dual antenna arrangement with a large antenna to track the target and a smaller antenna to track the outgoing missile.

    The last photo of the newest tracking radar antenna says:

    Detail of new Pantsir S1 1RS2-1 / 1RS2-1E PESA engagement radar, which is claimed to operate in the Ku-band. The small upper antenna belongs to the APKNR (Apparatura Peredachi Komand i Naprovadzaniya Raket) subsystem for datalink control of the missiles. The design has been credited to VNIIRT (KBP).

    The radar antennas (large one and small one on each radar mount) look about the same size, yet the first ones operate in the X and Ku bands and the new one operates in the Ku band.

    Please don't suggest that means the little antenna operates in Ku and the big antenna operates in the X band as the current system doesn't operate in the X band.

    BTW another name for the X band and the various Ku and K and Ka bands is Cm wave and mmw radar bands... to be used by the Mi-28N and Ka-52... for air and surface scanning for targets.
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    russian fighter aicrafts internal weapons bay

    Post  George1 on Fri Jan 20, 2012 1:03 am

    The bomb bay or weapons bay on some military aircraft is a compartment to carry bombs, usually in the aircraft's fuselage, with "bomb bay doors" which open at the bottom. The bomb bay doors are opened and the bombs are dropped when over the target or at a specified launching point.

    Large-sized bombs, which may be nuclear, are dropped from hook-type releases or bomb cradles. When a bomber carries many smaller bombs (e.g. iron bombs, JDAMs), the bombs are typically loaded onto mechano-electrical devices known as ejector racks, which allow for larger bomb loads to be dropped with greater accuracy.

    Military fighters are now designed to have the smallest possible radar cross-section, which has decreased very substantially since attention was paid to this feature. Large racks of missiles and bombs hanging below the wings return very distinct radar signatures which can be eliminated by bringing the weapons inside the fuselage. This also improves aerodynamic performance and increases the payload which can be carried. Examples of modern U.S. fighters with weapons bays are the F-117 Nighthawk, F-22 Raptor, and F-35 Lightning II.

    What about russian fighter aicrafts?


    Last edited by George1 on Fri Feb 05, 2016 3:28 am; edited 4 times in total
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Fri Jan 20, 2012 2:32 am

    The F-117 is not a fighter, it is a bomber.

    Russian/Soviet aircraft with internal weapons carriage include the Tu-16, the Tu-22M Backfire, Tu-160 and Tu-95 strategic cruise missile carriers, the Tu-142 maritime patrol aircraft, the prototype S.32 (the Sukhoi fighter with forward swept wings), the PAK FA, and the proposed Il-102 CAS aircraft.

    The Mig-31 has semi conformal weapons carriage under its belly.

    Internal weapons carriage on light fighter aircraft is inefficient and creates huge penalties on performance in terms of limiting the size and weight of the weapons that can be used and also taking up a large amount of internal volume which could otherwise be used for fuel, which makes any fuel savings in reduced drag a false saving as if that internal space was used for extra fuel the aircraft would be much simpler in design and likely have rather more flight range.

    The only design requirement that makes internal weapons carriage attractive is the stealth aspect, therefore any stealth aircraft that has internal carriage is likely stealthy enough to make it worth while.

    A plane like the Typhoon or Rafale that are "semi stealth" or Low Obserable are simply stealthy because it is a gimmick.

    When properly armed for a mission they are not stealthy, so stealth in their design is a marketing ploy to improve sales against aircraft that are actually stealthy.

    Ironically LO would be much more attractive if it meant cheaper than stealthy, but it doesn't.

    Of course after the first few days when the enemies AD network has been reduced to danger spots rather than a dedicated layered defence screen then external carriage becomes useful where payload and weapon capacity become more important than stealth.

    Internal carriage has the other advantage that it makes supercruising more efficient over greater distances, but the cost in fuel fraction probably balances the reduction in external drag in terms of flight range... especially at subsonic speeds.
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Thu Feb 02, 2012 12:03 am

    Fair enough... apologies to my fellow members Embarassed


    Back on topic, I am wondering about the two main weapon bays of the T-50.

    Has anyone seen decent close up photos of them?

    I wonder why they use two separate ones instead of one large one that could have been designed to carry a large missile in a semi conformal position.... or for that matter an FAB-9000 bomb... Smile

    I guess the larger doors of a single bay might be too heavy or uncontrollable in the slipstream...
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    SOC

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    Re: General Questions Thread:

    Post  SOC on Fri Feb 03, 2012 1:44 am

    GarryB wrote:Back on topic, I am wondering about the two main weapon bays of the T-50.

    Has anyone seen decent close up photos of them?

    I wonder why they use two separate ones instead of one large one that could have been designed to carry a large missile in a semi conformal position.... or for that matter an FAB-9000 bomb... Smile

    I guess the larger doors of a single bay might be too heavy or uncontrollable in the slipstream...

    You could easily have a large bay with two sets of doors. The logical answer is that they didn't need a bay that big. Or that there's some sort of fuselage structural component there that they couldn't cut through.

    I'd be more curious as to the apparent sensors or vents on the aft portion of the forward bay doors on T50-1 and T50-2. Are they sensors? What are they looking at, other than nothing to either side thanks to the engine nacelles? Are they vents? What are they venting, and is it only test equipment, or is it something that limits the weapons installation in the forward bays? Are they something else entirely, and why are they only present on the forward bay doors?

    Also, high-res pictures of the underside of both airframes shows that the bays aren't quite as long as they appear: the serrated edges at the forward and aft ends of the doors appear to rest on an internal structure (which is sensible, as they can close against that point and be more likely to get a flush fit to maintain RCS levels), meaning that the total useable length of either bay isn't exactly the entire length of the doors. Would need to come up with some accurate lengths to determine if this actually makes a serious difference given the sizes of the likely weapons to be installed.
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    George1

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    Re: General Questions Thread:

    Post  George1 on Tue Feb 07, 2012 11:16 pm



    Will PAK-FA have such a weapons bay?
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    GarryB

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    Re: General Questions Thread:

    Post  GarryB on Wed Feb 08, 2012 12:31 am

    Will PAK-FA have such a weapons bay?

    No.

    It will have two.
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    George1

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    Re: General Questions Thread:

    Post  George1 on Wed Feb 08, 2012 12:35 am

    GarryB wrote:
    Will PAK-FA have such a weapons bay?

    No.

    It will have two.

    Any photo?
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    Re: General Questions Thread:

    Post  GarryB on Wed Feb 08, 2012 10:27 am

    Several, but none with the weapon bays open...



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    Re: General Questions Thread:

    Post  George1 on Wed Feb 15, 2012 5:10 pm

    Kubinka training center is a combat base or just demonstration airfield?
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    Russian Patriot

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    Kubinka training center is a combat base or just demonstration airfield?

    Post  Russian Patriot on Thu Feb 16, 2012 2:22 am

    George1 wrote:Kubinka training center is a combat base or just demonstration airfield?

    both actually depending on circumstances....
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    Sujoy

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    Active Protection System For Fighter Aircrafts?

    Post  Sujoy on Tue Apr 24, 2012 9:14 pm

    Is it possible to design an ARENA type Active Protection System for fighter aircrafts like the SU 30 MKI and SU 35 ?
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    Re: General Questions Thread:

    Post  GarryB on Wed Apr 25, 2012 2:47 am

    Technically they already did... it was used in WWII on Il-2 aircraft.

    The system was called DAC-10 I think and consisted of a fused grenade with a small parachute that was launched upwards from the aircraft. After a few seconds the grenade detonated with the hope of damaging any fighter that could be behind the Il-2. The Il-2 in most later and earlier versions had a rear gunner so a tactic used by enemy pilots was to attack from behind (it was easier to attack from behind because the closing speed is much lower and there was more time to line up the target and shoot it down) and from below where the gunner couldn't engage them.

    Such a system would not be so useful now because missiles don't always approach from behind and below.

    The latest ESM suites include 360 degree IR detection of threats and targets and the Russian PAK FA has taken that a step further and added radar antennas to the side and presumably the rear to give all round radar coverage too. This is half the problem ARENA has to deal with... detection. All the assessment and interception calculations can be performed by the existing systems too, so that leaves us with the kill mechanism... what do you use to defeat the incoming threat.

    For most aircraft cannon fire is not a primary concern as you can fly above that, and it doesn't manouver to follow you so an indication from its IR and radar signature as a visualisation in your helmet mounted display should let the pilot "fly through it".

    For missiles or guided shells you can use a combination of a DIRCMs and towed decoys to defeat or fool the seekers or you can launch a missile to intercept an incoming threat.

    IIR guided lock on after launch missiles would be ideal for the latter and a high powered laser in a DIRCM ball for the former.

    For the Russian aircraft President-M includes DIRCM and towed decoys and for the PAK FA and likely Su-35 there is the 9M100 short range AAM with IIR guidance and Lock on after launch capability... it being the air launched equivalent of Morfei that will be used by the Army and Navy as ground launched missiles/CIWS.
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    Re: General Questions Thread:

    Post  Sujoy on Wed Apr 25, 2012 10:39 am

    Thanks GarryB . However, the R 77 and K 100 still have a high kill probability even if fired from BVR against aircrafts whose ESM allows for 360 degree IR detection like the F22A - Tranche 3.


    In BVR and WVR engagements, K 100 is guided initially by its inertial reference unit and microcomputer, which point it in the right direction based on instructions from the targeting aircraft or platform. A mid-course target location update can be transmitted directly from the launch radar system to correct that if necessary, an approach that may avoid triggering enemy radar warning receivers. In the final phase of tracking, however, the internal active radar seeker becomes completely independent and guides the missile through its own active lock-on. Reported range at about 30 miles.

    When coupled with modern radars, K 100’s guidance approach allows a fighter to launch and control many missiles at once, avoiding a dangerous fixation on one target. Its autonomous guidance capability also provides a pilot with critical range-preserving launch and leave capability, improving survivability and helping to avoid “mutual kill” situations. Even more advanced technologies are emerging that go one step further, and allow secure “hand-off” of a fired K 100 to allied fighters.

    The latest version of the K 100 uses smaller system components; with an upgraded radar antenna, receiver & signal processor; GLONASS-aided mid-course navigation; an improved datalink; and new software algorithms. The new hardware and software is rumored to offer improved jamming resistance, better operation in conjunction with modern AESA radars, and an improved high-angle off-boresight “seeker cone,” in order to give the missile a larger no-escape zone. Less-publicized improvements reportedly include a dual-pulse rocket motor, for up to 50% more range and better near-target maneuvering.

    The Latest version of the AMRAAM AIM 120D though smaller in size is believed to be influenced by the K 100.

    Under these circumstances the only available option for an aircraft to avoid being hit by such missiles is to have an Active Protection System.

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