MiG-29 Avionics

[PaulMM (Overscan)]

Thread to discuss MiG-29 Avionics. What more can we learn about this aircraft and its systems?

[PaulMM (Overscan)]

To start with, here are three diagrams which lewradar and I believe do not, as thought, refer to the Sapfir-23 series but to the N019/N001.

The first shows the basic twist cassegrain concept, but note that the fixed "parabolic" reflector in front and moving "flat" subreflector at back are not truly parabolic and flat at all, like in earlier radars, but more complex in shape.

The second shows the internal structure of the "parabolic" reflector.

The third shows the structure of the moving subreflector.

Perhaps lewradar can post here his comments on the design of this system.

[PaulMM (Overscan)]

N019 radar, minus the front reflector.

[lewradar]

Perhaps lewradar can post here his comments on the design of this system.

Cross-posted from Mig-23 thread:

The subreflector has to change the polarisation of the waves from horizontal to vertical so that they then pass through the horizontal wires unscathed.

The usual means of effecting this involves an array of wires at 45 degrees which reflects half the power of the horizontal signal. The other half passes through the wires a distance of quarter of a wavelength to the metal back surface of the sub-reflector where they are reflected. This extra path difference of half a wavelength  (quarter there plus quarter back) results in the two 180 degree phase difference waves interacting to produce the required vertical polarised signal for transmission. Section 8.9 of the Cassegrain document explains this using vectors.

Thus if (say) 12 GHz and 1.5 GHz  signals are to be so affected the sub reflector has to incorporate quarter wave thicknesses for both. Ris 10 in the document shows how this is effected: the basic thickness is a quarter wave for the 1.5 GHz signal. By incorporating a periodic array of small reflectors embedded in the material of the sub-relector at a depth of quarter wavelength for the 12 GHz signal this fulfills the requirement for both frequencies - both frequencies are changed to vertical polarisation for outward transmission.

[remember that the opposite effect will occur for received vertical pol signals and they will enter the horns as horizontal]

Look at the thickness of the subreflectors for Sapfir-23, -25 and smerch. Compared to these the N-019 sub reflector is much thicker - because of the addition of the IFF.

Twist cassegrain is a difficult concept: Skolnik “Introduction to Radar systems” 2nd Edition explains the basic concept on pages 242-243. He calls it a twist reflector.

-see MiG-23 thread for a quick and dirty scan of the pages ( I won’t clutter the place with duplicate copies)

[loco]

i'd like to learn about the Gardenya active jammer for the Mig-29, way too many "urban legends" are being said about, (crappy commie stuff etc  )
but around you guys, i'm sure, the info will be accurate and objective  8)

thamks a million

Loco.

[PaulMM (Overscan)]

I believe that according to Oleg Samolovich from Sukhoi's memoirs, the Su-17 team lead by Zyrin refused to redesign a version with internal Gardeniya jammer (post Beka'a Valley) on the grounds it was crap and a waste of space.

The Su-27 Flight Manual includes a nice Gardeniya pod manual, which I can post a translation of here after my holiday.

[loco]

thanks Overscan.
now doing some thinkin'
the Bekaa valley... wasn't that during the seventies?, it seems to me that 30 years after, it could have been upgraded to a more reasonable level, because the Peruvian experience in the 1995 war, was to send Su-22's to battle not only with far outdated Sirena-2 RWR but without "any" EW suite, call it Gardenya or anything for that matter, loosing 2 of them with the pilots KIA against an electronically far superior opponent.

in my humble oppinion, Mr. Zyrin's desition was a bit... precipitated (i wasn't there so i can't say for sure  )

i think there are some facts where Gardenyas were able to defeat a few AMRAAM's in the past decade, please correct me if wrong.

thanks to all

da Loco.

[Pit]

Loco, how are you.

Bekaa Valley was in 1982, Gardeniya R&D quickly started after that. Not only Su-17 was slotted for receiving the equipment, there were also MiG-23MLD prototypes and the intention to deploy it on Su-24M.

Every one of them screwed the idea. It was crap, plain and simple, the R&D was so accelerated that it was not an effective piece of eqipment. MiG-31 and Flanker were slatted to receive the much more advanced (years light ahead) L-005S from KNIRTI, and the L-203BI for MiG-29 9.13 only worked from 1989...before it didn't fit the thing well.

I have heard the opinion from many MiG-29 pilots (from thirds persons, althrough trustworthy individuals) that they would love to exchange the crappy Gardeniya for more fuel...

S. Moroz also refers to Gardeniya as basically crap in his Su-24M book.

There are surely upgrades, maybe inlcuding DRFM technology chips into it, but...oh boy you're far better with the newer pods like the MSP-418K...save the space inside the humpback for something more useful.

It seems that due to the extremly fast R&D the resulting TsNIRTI hardware resulted to be pure crap...and you have many examples of useful soviet ECM equipment like the SPS-141MVG-E, that was indeed retained in Su-17M3/4 instead of this Gardeniya thing.

Saludos amigo. 

[loco]

Salu-2 hermano PIT  8)
i had no idea that the gardenya system was that bad 
well if its worthless, better to get the new MSP-418K, i just dont like the idea of waisting a pylon to carry it, but its also clear that the use of "escort jamming" tactics would require only one or two of those jammers to hide a complete attack package...
and sure, using that fresh empty space for fuel, could give the Mig-29 a few miles extra range.

but if somebody decides to actually fix gardenya, wouldnt it be only necesary to improve the receiver and its processors computing power?
ok say... re-design it from scratch (sorry i'm running out of "gray matter"  )

the madman.

[Dilbert]

I have heard the opinion from many MiG-29 pilots (from thirds persons, althrough trustworthy individuals) that they would love to exchange the crappy Gardeniya for more fuel...

S. Moroz also refers to Gardeniya as basically crap in his Su-24M book.

I can't find the reference to Gardeniya in Moroz's book.  Perhaps you are referring to Landysh/Fasol/Mimoza of the Su-24MP, and the reason that more of these EW-specialized aircraft weren't produced?

It's interesting to read so many opinions that Gardenia is "crap," without any explanation.  My impression is that rather, ECM in general is becoming "crap," with all the home-on-jam missiles around - witness the relegation of the B-1B, the retirement of the EF-111, the ability of EA-6B to operate against no newer threat than the SA-8...  Simply, any modern radar will have the ability to switch its operating frequency faster than a modern ECM can follow.  The new ECM thus isn't bad, it just isn't operationally any more effective than the old ECM - and thus not worth the cost of upgrading.  The only advantage Sorbtsiya ECM has over Gardeniya is "terrain-bounce" capability, grace of its steerable antenna - and even this is a sketchy technique that only works at low altitude, over reflective terrain, and against which the AIM-120 already has an operational ECCM software to defeat.

Thus it's not the Gardeniya, but rather ECM as a whole, that needs to go in the dustbin, to be replaced by stealth technology.  The only reason ECM is allowed to continue to exist at all is to fight opponents armed with obsolete equipment - i.e., anyone the US is likely to fight - or because the country in question has no stealth technology of its own to field - i.e., everybody else.  In this regard, it makes little sense to pick on Gardeniya in particular.

And since when is a MiG-29 pilot an expert on ECM, of all things?  I haven't even heard of one who knew what "loft" was.   

[JCage]

Hi Dilbert,

Would HOJ mode work on deception jamming or range gate techniques, ie anything other than simpler noise jamming?
Also, a MiG-29 Pilot would surely interact with maintenance crew and learn about its operational procedures and what & how effective it was deemed to be. If a pilot says something is crap, then it means that it probably does not work as designed or that its hard to use or its prone to failure/ not serviceable.
Also if ECM is going the way of the dodo, but EA-18Gs are still being introduced, and the newer ECM suites are claimed to work against SA-XX suites. So I guess it does depend on what you have...if you dont have stealth, ECM is the way, but if you have stealth, using ECM is akin to announcing you are in the area. OTOH, if you do employ stealth fighters, you may still need to use ECM to just ensure that some particular old gen, long band radars etc are no longer viable...for they might pose a threat to your silver bullet stealth fighter which is optimized against "newer/ more commonly in use" freq bands.

[Dilbert]

Would HOJ mode work on deception jamming or range gate techniques, ie anything other than simpler noise jamming?

It would depend on the type of DECM and HOJ - there are different methods to achieve both.  In general though, the HOJ missile should work unless the DECM is specifically designed to defeat it (e.g. if the enemy captures one of your missiles and reverse-engineers it).

Also, a MiG-29 Pilot would surely interact with maintenance crew and learn about its operational procedures and what & how effective it was deemed to be. If a pilot says something is crap, then it means that it probably does not work as designed or that its hard to use or its prone to failure/ not serviceable.

US pilots in Vietnam were also dubious about the value of ECM pods, and routinely complained that they would have preferred to carry a few extra bombs instead.  Combat experience proved the worth of the ECM pods in spades, despite those pilot opinions.

[PaulMM (Overscan)]

The uselessness of the early Gardeniya is referred to in Oleg Samolovich's memoirs. He says that, post Beka'a Valley, a decree came in to stick Gardeniya in or on every aircraft. Zyrin, chief designer of the Su-17 series, was the only person brave enough to stand up and decline, on the grounds that it was ineffective. He got into a certain amount of hot water over it, but was rehabilitated when it rsubsequently proved pretty much useless in service.

[Dilbert]

The uselessness of the early Gardeniya is referred to in Oleg Samolovich's memoirs. He says that, post Beka'a Valley, a decree came in to stick Gardeniya in or on every aircraft. Zyrin, chief designer of the Su-17 series, was the only person brave enough to stand up and decline, on the grounds that it was ineffective. He got into a certain amount of hot water over it, but was rehabilitated when it rsubsequently proved pretty much useless in service.

Why did the Su-25T carry the Gardeniya, if the Su-17 was correct to omit it?
Why did the Su-25 lack the SEAD capabilities of the Su-17?
What makes the Sorbtsiya carried by the Su-27 more effective than the Gardeniya on the MiG-29?

Sukhoi memoirs always seem "managed" to me - more interested in sticking to a marketing script, than actually answering any meaningful questions.  I can't forget that these are the same people, who now tell us about "plasma stealth..."  and that the F-22 has "0.3 sq.m." RCS...   

[Pit]

Dilbert, are not L-005S based in an altogether much more advanced technology that L-203BI?

AFAIK, and I have received some confirmation of this (althorugh from no Russian source but a good source anyway), they use Cross-Polarisation Deception Jamming (Cross-Eye), they can jam even 10 different radar emission (pulse, pulse doppler) at the same time (Gardeniya-1FUE in Su-27SK is limited to 2), contrary to Gardeniya, Sorbtsiya-S was considered not ready for export till 2001...it's cool and it can jam both front and rear hemisphery .

It was made to work along the "L-001 Smalta-SK" master ECM Pods, but those were never bought by the VVS

Check that Su-25TM uses an improved set (Omul, based on DRFM technology also used by MSP-418K from the Kedr EW Suite), first tested in 1998.

Su-25 used old and capable (and combat tested by long time) SPS-141MVG/MVG-E