stealthflankerThe one im kinda worried is that one cant really stock large number of parts as these parts too are having shelf life (E.g RVV-AE missile have shelf life of 8 years on storage) Our Mi-35 and Mi-17 sometime undergo early maintenance mainly to “expend” stocked parts.
I wonder tho if there is any procedure or firm specialized in zeroing or at least certify these parts so they can be used.
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stealthflankerProblem with Russian fighters are most often not related to the aircraft itself, including maintenance.
As seen we often have parts shortage and rather expensive scheme of sending the plane for heavy maintenance. Which i wonder how procurements work in the operators. For Indonesia case, we did have problem in spare parts procurement where Rosoboroneksport itself playing with the price and we need to negotiate quite hard for it. The bigger problem however came from our own side where our locals do some corrupt scheme that actually increase the maintenance cost. Plus the fact that we didn’t order or operate so many aircrafts in the first place which i assume in the eye of the russian, seems weird for us to do our own heavy maintenance.
The US Scheme in other hand is directly related to FMS (Foreign Military Sales) Which very good as it actually more transparent, but it has nothing to do with maintenance. The US did provide us with F-16 heavy maintenance including Jet column to test the F-100 engine (This however have to be renewed if we do order later F-15 or F-16 variant with GE-F132 or PW-229) and C-130 maintenance. But that does not prevent our airforce from having maintenance in Airod anyway and do structural enhancement in Turkey. Plus our own spare part procurement sucks as it can take 1-2 years before the part really come and repair can begin.
For Malaysia case i heard it was because the PM cut contracts with the Russian firm and insist G2G procurement which, BTW not the way Russia sells arms.
stealthflankerSeriously. These are getting so old.
Some step for better discussions :
1.Stop leap of faith.
One need to stop comparing APS radar with missile seekers. two of which built for very different purpose and therefore having different design choices where one cannot take another’s job. Let’s take example of RVV-AE Seeker vs much larger ARGS-54 seeker.. They’re from XXI Centuries Encyclopedia : Russia’s Arms and Technology.
[ATTACH=CONFIG]262126[/ATTACH]
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Notice similar range despite the latter being bigger (and by logic can have bigger transmitter etc). Because they were handling different situation. A2A missile is expected to have mid course update, very narrow acquisition box and therefore less clutter so they could acquire at such range. Anti ship missile seeker ? it has sea states to contend with, clutter and the fact propagation is kinda unfavorable at low altitude.
APS Radar face same problem as the AsHM added with multipath which may force it to limit range and perhaps EMCON consideration that forces it to compromise frequency or power limitation that require it to operate at lower band thus sacrifice resolution
2.Quantify the claim.
We all know and aware of Raptor or JSF RCS BUT. one annoying problem is.. for what frequency. For some reason wavelength dependence on RCS is often neglected in anyone’s argument which no one never bother to rectify. For some reason. It’s pointless to say value without anything underlying it.
stealthflankerJ/apg-2 is part of the AESA sensor of the missile it already stated that in that source. AAM-4b uses J/apg-2 radar, K-77M uses Izdeliye-50-1 radar, do you get the hint? You will even see the radar on the K-77M and the radar on the AAM-4b(even though its a picture)
Do you even aware that such operating modes are nothing special ? Our old N001VEP on our Su-30MK2 can do the thing, providing Mid-course update for RVV-AE even without itself being an AESA ?
Remember Japan added a 40% longer autonomous range than the Agat which they clearly stated.
and this Autonumous range does not say the seeker’s range. But the distance where it goes active and start searching target on its own.
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I wanted to see a bigger picture to see the amount of modules on the T-14 since its already stated the SU-57 has 358 for sides. Which is why I wanted a decent comparison.
And i will tell you if they indeed even work in same band. It will have Less amount of module and perhaps even Lesser power due to the fact we may not have 200-250 kW power generation of fighter aircraft. It’s a common sense.
stealthflankerYou have probably have not paid any attention to the last pages going on in this thread which is understandable. Agat missile sources suggested it can create a 20km lock on utilizing its own sensors. J/apg-2 from sources back claims 40% longer autonomous range than Agat r-77. https://defense-update.com/20120314_…re-lethal.html
If you really understand what you read. You would see that the range figures refers to A-Pole or when the missile goes “active”. It says nothing about the range of the active seeker itself. The 20 Km figure is the range where the AAM Goes “Active” and start searching for its own target.
You should also NOT compare the APS sensor onboard a tank with fighter radar as both designed with very different purpose in mind and may have different design, say power allocation or even frequency band. You seriously make a leap of faith which unfortunately undesirable if any serious discussion to be held on the subject.
stealthflankerYou don’t compare APS with Aircraft radar. We dont even know in what band Armata radars work.
stealthflankerI clearly know. But let’s be real and do a google earth., then you would see what i mean. Then search Sipri for how many Pantsyrs or Buk they purchase. You would clearly see there are just not many of them to cover whatever Israeli wants to strike. Unless very few strategic place.
or maybe we could have..sorry for the lack of better word.. flat earth ?
stealthflankerAnother occam’s Razor also state Because they don’t have enough coverage.
stealthflankerYeah and then it depend on whether Syria can mobilize their assets there. If it can’t or there simply too many munitions to handle then it got saturated.
We never really seen Syrian MiG’s doing anything even in daylight and early warning was available. So it’s all down to their ground based system which they dont have many of it and have limited target channel. handful of pantsyrs wont be enough for the task.
stealthflankerDid they deploy Nebo SVU or Nebo UE in Syria ?
If they don’t they only have like S-band 91N6 and 96L6 which are S/L band. and if they did indeed deploy, we still have line of sight problem. as These system are deployed only in Hymeim and nowhere else.
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Low band radar still have its promise and i believe US will definitely look for same solution had Chinese start pulling their own version of B-2 or Russian finally wake up and finish whatever they got.
stealthflankerLooks to me it’s reclined
https://www.airplane-pictures.net/photo/723226/40-france-navy-dassault-rafale-m/
click on the link. it’s a Gripen photo inside.
stealthflankerAnd you seems to be out of touch regarding radar service hours
The AESA on both SH and F-15 had TERRIBLE sustainment hours..
Will having gimbals fix the matter ?
Then if AESA is terrible.. how does it compare to just 200-500hr of conventional TWT which BTW will also make your radar completely unusable when it fails.
stealthflankerWhat you just said made no sense.
ESA radar with Gimbals one way or another has been on the market for a loong time now.
If it fails ? you lost entire coverage on one side. and why they need gimbal in the first place ? To reduce cost and further cooling/integration burden of having multiple array. Remember that AESA radar is advertised for being reliable because it can be solid state (NO moving parts), or simply to try bear full gain of antenna off boresight.
The Pros about using Gimbals on Radar Array, you can scan an entire sector to your left(or right), while your desired heading 120-140 deg off.
Exellent example, you are fencing a airspace border. You know one side is friendly, other side not friendly.
This can be done, even better with multiple array face. Why do you think we have ground based radars like AEGIS having multiple faces covering 360 deg ? and let’s look at APAR, then Australian does it with 6 faces with their future Type-26 frigate and Anzac.
stealthflankerJust for my own curiosity I am wondering rather if this technology was available at the time for Russia to implement on the SU-57 because they went from mechanical steering to more modules focused on the front than the sides, While Leonardo says the beam moves at a rapid speed to cover a wider beam. If Russia had this option available would they have ditched the 358 side radar arrays if a 240 degree radar beam azimuth with electronic steering was available? It seems that SAAB likes to implement a wide radar beam
The Su-57 approach is superior. Mainly because it does not introduce mechanical element. Something which any ESA designer trying to avoid. and it provide true coverage. The swashplate or mechanical steering does provide increased coverage in one side but sacrifice the other, pretty much like you turning your head left and right. You turn right, you cover entire field on the right but not on the left.
The downside is of course the array costs and increased cooling and power supply requirement as each array face may need their own set.
stealthflankerThanks, Rall.
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A little update regarding the calculator and some additional thoughts.
The fixed-version
http://www.mediafire.com/file/s8ea52zoc8zzf17/AESACalcStable.xlsx/file
The fix mainly deals with confusion regarding finding the number of beams and determination of dwell time for linear array. The previous version is unfortunately using conventional volume search equation where the radar Had to have elevation beam scanning. Something which linear array doesn’t have. I deliberately delayed Moonlight’s suggestion few pages before to find better reference instead on relying on my own decision (as the excel calculator itself already contained perhaps many of my own decision, especially the weather tab which essentially a cheat and even simplified version of K.Barton’s model instead of more proper L.V Blake model, but i haven’t able to find way to implement in excel).
In this version the equation for the linear array is derived from one found in the book “Air and Spaceborne Radar an Introduction”. French Radar book which all Rafale/Mirage enthusiasts must already know about.
The basic equation :
[ATTACH=CONFIG]261867[/ATTACH]
Where Te is the Dwell time while 20 seconds is the time frame to search the area, 360 deg is the scanned area (which in spreadsheet reduced to 120) and 1.2 Degrees is the scanning azimuth beamwidth. Since the dwell time is already known (selectable from the user interface) One now only need the beamwidth and scanning area to find the appropriate answer.
Given the emergence of Linear array radar, like NIIP L-band, E-2D Hawkeye, Chinese Recconaissance UAV and US Joined-wing AEW concept. The ability to predict radar range of these arrays become important, not only for “serious” application but also general enthusiast who wish to “get to know” how these arrays might perform. A word of caution however is that the spreadsheet is only for sector scan radar not for rotating one. So if you wish to predict range for E-2D Hawkeye radar, assume that the rotodome is stopped and the radar would be in sector scan mode.
Another food for thought i would like to present is the Radar Cross Section variable. This topic is admittedly very complex yet unavoidable if one wish to actually make better guesswork on radar performance. The big question is “What RCS value i have to fill for the variable ?”. Given the multiple dependence nature of RCS. 0.001 sqm in one frequency would not be valid in another and one may not always have access to more complex modeling or information. Especially if one wish to do the assessment for low observable target.
As we know that there is wavelength dependency of RCS, i concentrated my efforts towards it. The “Radar Cross Section 2nd Edition” book by Knott and Tuley had the squared wavelength dependency, which need to be understood as base. It turns out that the dependency is basically a base 20 Logarithm of the frequency in question subtracted by the “target frequency”. Example of use.
We have an object designed to have 0.001 sqm or -30 dB RCS in 3 cm wavelength, what’s the likely RCS in L-band of 24 cm ?
We first do some logarithm works :
The 3 cm band (0.03 m)
20*LOG(0.03) = -30
Then the 24 cm band (0.24 m)
20* LOG(0.24) = -12
The we subtract the first band with second one. Thus. -30-(-12)=-18 Now we see the 18 dB difference. We can further subtract the RCS of the object in dB with the resulted value from our first equation.
RCS in L-band= -30-(-18)
RCS in L-band = -12 dB or 0.06 Sqm.
There are however always an exception as one cannot generally use the squared wavelength dependence on all stealth objects. As described in following papers :
https://www.scribd.com/document/384691562/Kuschel-H-VHF-UHF-Radar-1-Characteristics
and for those who interested in promises and features of low frequency radars the 2nd part of the paper
https://www.scribd.com/document/384691412/Kuschel-H-VHF-UHF-Radar-Part-2-Operational-Aspects-and-Applications
The squared wavelength dependence appears to only applies toward conical object or ogival, which would make it suitable for predicting missile weapon RCS. Other military systems which does not exhibit such shape might follow wavelength dependence (which if one interested can be run down with same procedure i described BUT using 10 as multiplier instead of 20).
and now the question is “Which dependence i should use to fill ?” This is mostly based on my own simple observation. Based on what was available, especially with this famous image, courtesy of secretprojects.
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The object with many facets (the lockheed Have Blue) appears to follow the squared wavelength dependence while the Northrop XST which incorporates some curvi-linear elements (This feature would be observed in subsequent stealth fighters and missiles like YF-23A and B-2). One can see the dependence from the difference of RCS between high band (the X-K band) with the one in the lower 175 MHz band. The faceted have blue have 30 dB more RCS which quite close to the squared wavelength approximation (which put 34-39 dB of difference) The Northrop XST in other hand have 8 dB of difference which close to wavelength dependence (the procedure will give 17 dB of difference which basically 50% more).
This is admittedly subjective and would cause confusion. As there is no real measure to “see” how faceted or curved an objects are.
Another thing with the procedure i described above, one may find the conventional target to have “lower” RCS value in low band radar. Say 3 sqm fighter in X-band become 0.04 Sqm in L-band. This is not because the fighter is stealth, but it can be explained by simple antenna-beamwidth relationship. If we take aircraft as simple plane and expose it to radio signal of increasing wavelength, one might observe that as the wavelength grow, the reflected power would be weaker (thus lower RCS) One can see this in real life measurement of conventional aircraft RCS.
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Further observation or suggestion however is appreciated.
My other observation toward shapes however still suggest that somewhat, even curvilinear shape can still follow squared wavelength dependency. This is the aircraft based on Tacit Blue. Frontal area RCS on multiple frequencies.
The aircraft :
[ATTACH=CONFIG]261872[/ATTACH]
RCS in Multiple frequencies.
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Notice the 25 dB diffrence between X band and the VHF band.
My take on the matter however is to use both wavelength dependence to establish “best and worst” case approximation of the RCS of the object. Where the wavelength is best case and squared wavelength serve as worst. Then calculate detection range based on both values in the spreadsheet to generate possible detection range.
Suggestions and critics are welcome. It’s indeed complex and controversial topic. But as i said before unavoidable if some realistic range figure/number have to be found.
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