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RWR Missile Launch Logic Tree


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I made this logic tree based on how RWR launch indications are currently presented in DCS.

 

As I only know what outcomes the ED team has presented to us, I've filed in and assumed the variables that make sense for these outcomes. This is meant to help newcomers and potentially help debates about what should and what shouldn't occur if these principles are maintained.

 

Please don't flame me!!! : smilewink: And let me know if you see any mistakes.

 

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Well, for newcomers, I would explain things abour IR homing missiles launched whithout using radar since you added AIM-9 already. I know it's RWR but... you know... newcomers ;)

btw: Considering myself intermediate I still learned few things from your post.

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Don't know how its designed in the game, but...

 

Does the RWR detect CW illumination -> yes -> initiate launch warning...example R-27ER launch

 

Does the RWR detect HPRF illumination(HPRF STT) -> Does the RWR detect M-link -> yes -> initiate launch warning...example AIM-7 and AIM-120 launched in STT

 

Didn't you swap the R-27ER and AIM-7 around? :)

 

The R-27 missiles were designed for the MiG-29(R-27R) and Su-27(R-27R and -ER) - neither the N019 nor the N001 have CW illuminators for SARH support and the R-27R and R-27ER are both guided via M-link during initial stage of flight.

 

The AIM-7 is a much older design and initial versions of the missile were supported by CW illuminators(e.g. from AN/APG-63 on F-15A). Later upgraded versions(such as AIM-7M) used HPRF illumination for SARH, but still didn't have M-link support. Only the latest version - the AIM-7P has datalink(and IIRC even only on Block II).

JJ

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It's only correct for some users of 7F, and it's not correct for R-27R.

 

7E is capable of CW only. 7F is capable of CW and PD. 7M and R-27R use PD.

 

Although the 7F/M doesn't use M-Link, the radar signature still changes according to people who listened to the audio. I have my suspicions as to why, but it's speculation based on 3rd party account anyway.

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It's only correct for some users of 7F, and it's not correct for R-27R.

 

7E is capable of CW only. 7F is capable of CW and PD. 7M and R-27R use PD.

 

Yup.

 

Although the 7F/M doesn't use M-Link, the radar signature still changes according to people who listened to the audio. I have my suspicions as to why, but it's speculation based on 3rd party account anyway.

 

I did wonder about that - i.e. whether e.g. an upgraded version of the APG-63 radar will establish an M-link regardless of whether the selected missile can take advantage of it or not.

JJ

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I suspect it has more to do with providing a waveform that the sparrow can use to range its target, but that would assume that it needs something a little different than HSTT (which is maybe why they call it HSTT+? I'm not sure, I could be confusing things here).

 

The M-Link was added when AMRAAM capability was added, and I haven't read anything to indicate that it is generated when sparrows are employed ... but there's also nothing to contradict this.

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You sure about that?

 

If those missiles dont use CW SARH why do even the newer flanker radars, BARS and IRBIS, have CW illumination?

 

http://www.ausairpower.net/APA-Flanker-Radars.html

I have not seen any manuals mentioning CW illumination. Further, the seekers are advertised as monopulse PD type.

Carlos' website isn't exactly an accurate source.

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I spent some time looking back, but didn't find anything concrete yet (I have too much stuff to go through and I don't wanna). Ont he other hand, it's a look-down, shoot-down missile. Doesn't quite inspire CW thoughts, which in AI radars is typically bereft of doppler discrimination.

[sIGPIC][/sIGPIC]

Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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You sure about that?

 

Yes pretty much :)

 

Anyway, you asked for sources, so I looked around and found the following(highlighted the relevant passage):

 

Основными отличиями РГС 9Б-1101К от ранее разработанных РГС стало отсутствие в РЛС самолета специального передатчика подсвета (подсвет осуществляется в рамках временной диаграммы радиолокационного прицельного комплекса самолета) и наличие в составе РГС инерциальной системы управления и линии радиокоррекции, что значительно увеличило дальность пуска ракеты. После схода ракеты она, с помощью РГС в зависимости от ситуации, наводится на цель по обычным или же по специальным траекториям, алгоритмы которых реализуются в РГС. Работы по РГС 9Б-1101К запомнились огромным объемом испытаний. Два комплекса — МиГ-29 и Су-27, в ракетах которых применялась эта РГС, имели различное математическое обеспечение, разные версии работы. Иногда правильность алгоритмов работы БРЛС приходилось проверять пусками ракет. В результате в ходе отработки этих комплексов было проведено много десятков пусков ракет.

 

ФГУП Московский НИИ "Агат". История создания и развития. 2001 г.

 

Its an excerpt from an account of the history and developments of "AGAT"(the developer of the missile seeker in question).

 

A Google translation(well) of the highlighted part:

 

"The main differences between the CSG 9B-1101K and the earlier developed CSGs was the absence of a special illumination transmitter in the radar of the aircraft (illumination is carried out within the time diagram of the radar sighting complex of the aircraft)."

 

If those missiles dont use CW SARH why do even the newer flanker radars, BARS and IRBIS, have CW illumination?

 

http://www.ausairpower.net/APA-Flanker-Radars.html

 

What Esac_mirmidon and GGTharos said.

 

I have no idea where that site got the impression that they do - may simply be a case of common misconception that STT/SARH support automatically means CW illumination.


Edited by Alfa

JJ

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Ont he other hand, it's a look-down, shoot-down missile. Doesn't quite inspire CW thoughts, which in AI radars is typically bereft of doppler discrimination.
CW waveforms have excellent Doppler resolution, even better than HPRF. The problem with look down is targets hiding in the doppler notch, and neither HPRF or CW waveforms can prevent that.

 

 

Its an excerpt from an account of the history and developments of "AGAT"(the developer of the missile seeker in question).

 

A Google translation(well) of the highlighted part:

 

"The main differences between the CSG 9B-1101K and the earlier developed CSGs was the absence of a special illumination transmitter in the radar of the aircraft (illumination is carried out within the time diagram of the radar sighting complex of the aircraft)."

 

 

 

What Esac_mirmidon and GGTharos said.

 

I have no idea where that site got the impression that they do - may simply be a case of common misconception that STT/SARH support automatically means CW illumination.

I think you've mis-interpreted that paragraph. The N001 and N019 were some of the first russian airborne radars to integrate the illuminator into the primary radar.

 

Mig-25 and earlier jets had a entirely separate antenna and transmitter from the main tracking radar for SARH illumination. From an engineering perspective, this is something worth bragging about as its certainly highlights the complexity of the system.

 

 

Also, it mentions "illumination is carried out within the time diagram of the radar". IDK if this was completely translated correctly, but I take this to mean that the illuminator time shares the antenna and transmitter with the normal tracking waveform. Indicating two separate waveforms. This seems like something that would be necessary if the illuminator was CW. If the illuminator used a HPRF, then its not likely to need to time share as the tracking waveform would also be the illuminating.

 

Its important to note that IF it does use a CW waveform for illumination the radar would not be able to track the target (because there is only one antenna and radars of this design/era cannot transmit and receive at the same time. So switching back and forth between the tracking waveform and the illuminator (time sharing) would be necessary to continue to point the illuminator at the target.

 

Excellent post BeamScanner. So you’re of the opinion FLOOD mode should not trigger a launch warning? That was my thinking as well.

Yes, IMO flood mode should just look like HPRF STT. However, someone could argue that HPRF illumination looks different than regular HPRF tracking. And that would be an interesting debate that wouldn't ever be solved.

 

However, there is one thing we can guarantee. Launching a missile in FLOOD mode shouldn't change the FLOOD waveform what-so-ever. Thus there can only be two options.

 

1. FLOOD mode gives STT (lock on) warning.

or

2. FLOOD mode gives launch warning (even if no missile has actually been launched).

 

Considering how powerful #2 would be in game, I'm willing to bet people would be content with #1. Again, I think #1 is the more likely scenario.


Edited by Beamscanner
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CW waveforms have excellent Doppler resolution, even better than HPRF. The problem with look down is targets hiding in the doppler notch, and neither HPRF or CW waveforms can prevent that.

 

Doesn't matter, wasn't used for clutter rejection in old radar sets. :)

 

I think you've mis-interpreted that paragraph. The N001 and N019 were some of the first russian airborne radars to integrate the illuminator into the primary radar.

 

The F-15 CW modes too. So did the F-4 before it. It was removed after the 7F was superseded by the 7M. The N001 and N019 never had any CW modes that we know of, but sources are difficult to get and harder to translate when you do have them.

 

Also, it mentions "illumination is carried out within the time diagram of the radar". IDK if this was completely translated correctly, but I take this to mean that the illuminator time shares the antenna and transmitter with the normal tracking waveform. Indicating two separate waveforms. This seems like something that would be necessary if the illuminator was CW. If the illuminator used a HPRF, then its not likely to need to time share as the tracking waveform would also be the illuminating.

 

No CW modes are mentioned anywhere in the manual. You're looking for a needle in a haystack for something that should be standing out.

Further, as far as time sharing - even with PD illumination you must time share transmit and listen by the radar itself, never mind scheduling blanking for RWR and jammers - so I think you're reading way too deep into this time-sharing thing with respect to available illumination.

 

Yes, IMO flood mode should just look like HPRF STT. However, someone could argue that HPRF illumination looks different than regular HPRF tracking. And that would be an interesting debate that wouldn't ever be solved.

 

The STT mode is called HSTT+. That may not mean a different waveform, but certain crews had indicated that there's an audio tone change.

 

Considering how powerful #2 would be in game, I'm willing to bet people would be content with #1. Again, I think #1 is the more likely scenario.

 

We've had #2 before. And it was king.

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I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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I wasn't stating that the manual mentioned anything about CW. I was countering Alfa's post. I think he mis-interpreted the text he posted. I think all it was saying is that the illuminator is integrated into the primary radar rather than having a separate illumination antenna and transmitter. My example, the MIG-25, has its illuminator antennas at the wing tips.

 

label 34 and 50 in the below link

 

http://aviazioneaereimilitari.altervista.org/blog/wp-content/uploads/2013/05/MIG-25.jpg

 

I am not certain if CW is there or not. But I have yet to see anything stating that it uses HPRF illumination.

 

Doesn't matter, wasn't used for clutter rejection in old radar sets. :)

I think were on different pages here. I'm not saying CW waveforms were used for tracking or detection. I saying that CW waveforms are perfectly fine for illumination. The primary downside being that its obvious to the target that they are being launched on since 'normal' search and tracking waveforms are not CW. IMO the push for HPRF illumination was its ability to hide the fact that you are illuminating the target. Though I'm sure other factors like transmitter functionality and duty cycle limits were also factors.


Edited by Beamscanner
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The push for HPRF illumination was probably for simplifying things, as well as more modern capability. For one is delivers more power on target, thus allowing a missile to track a target further from the illuminator.

 

The flanker manual never mentions any tracking or illumination modes other than HPRF. While it doesn't go into as much detail as the F-15's -34 about what the radar is doing, there's simply no mention of such a thing.

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Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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I think you've mis-interpreted that paragraph.

 

Thats entirely possible, but I don't think so.

 

I wasn't stating that the manual mentioned anything about CW

 

So where do you get the impression CW is being used? - I mean if there is no mention of it in the aircraft manual and no indication that a CW illuminator exists, wouldn't it be more appropriate for you to provide a credible source proving(or indicating even) that it does?

 

I was countering Alfa's post.

 

Oh so thats what you are doing :D

 

.. I think he mis-interpreted the text he posted. I think all it was saying is that the illuminator is integrated into the primary radar rather than having a separate illumination antenna and transmitter.

 

I cannot understand how you could interpret this:

 

"The main differences between the CSG 9B-1101K and the earlier developed CSGs was the absence of a special illumination transmitter in the radar of the aircraft (illumination is carried out within the time diagram of the radar sighting complex of the aircraft)."

 

...as the CW illuminator just being integrated with the radar, when it clearly states that there isn't one.

JJ

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I would wait for ironhands input. Great work though.

AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS

 

Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.

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As an interesting aside:

 

So to lipchane they proved to be as those checked in Mari, and after by their destroyers MiG-29 strips touched chassis Tu-154, on which to the base of profit the representatives of almost all basic OKB, which worked on fighter aircraft. In the course of a series of experiments it was rapidly explained that developed OKB MZ “Vympel” the controlled intermediate range rocket R-27 with semi-active RL GN and IR GSN (considered as answer to American AIM-7F “Sparrow”) it does not answer according to its characteristics by declared in the documentation given, and not only does not exceed from the basic parameters American ammunition, but also it sufficiently noticeably is inferior to it. To the honor of the colleagues of OKB MZ “Vympel” it is necessary to say that they within the completely compressed periods prepared for the series production the improved versions of rocket (R-27RE and R-27TE), which completely overlapped American article from all parameters and with the significant reserve.[...]

Source:

Pilot 1st Class, Colonel Pyotr Kartashev at Istoriya Aviatsiya

"Metamorphosis of the Air Combat training of the Soviet Air Force in the Post-war period"

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Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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Sorry my friend, another mistake. Except few very early aircrafts and some export machines Mig-25P/PD/PDS never had any RWR. This is her big secret :). Those tips are just anti-flutter and on sides have IFF antennas.

I know they are antiflutter weights... and I did not say every mig25 was like that... it depends on what is installed and for whom (spo3, spo15, etc.). What is sure is that these have no illumination function :)

MiG-25_Cockpit.thumb.jpg.75a11da77316c8a55137a630af2a6113.jpg

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As an interesting aside:

 

Yes although a little vague as to whether they are talking only about aerodynamics/propulsion or also guidance.

 

I have read somewhere that it was accepted that seeker performance was not competitive and that the push to introduce INS/radio correction on the R-27R was really seen as a way to compensate for that rather than to trying to "out-perform" the US equivalent.

 

At least the stated acquisition range of the 9B-1101K of some 25 km vs. RCS of 3m2, seems to fall quite short of the seeker ranges you provided for the different versions of the AIM-7 here:

 

https://forums.eagle.ru/showpost.php?p=3296483&postcount=21

 

BTW in connection with earlier discussions on the matter - I have found several sources confirming that the max range of radio corrected flight for the R-27R is 25 km(or 30 seconds duration) and one claiming that maximum duration of controlled flight is 60 seconds - I guess this would mean in total(radio corrected + SARH).

 

I also remember reading that the development of the R-27ER(which btw seems to have been operational around 1987 vs. 1984 for the -R) also involved modifications to the guidance system e.g. ability to launch from higher altitudes(which makes sense) - i.e. wasn't just a matter of sticking a larger motor section on the R-27R as the "modular concept" could give the impression of.


Edited by Alfa

JJ

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