27R/ER Cannot relock

[NuII]

Hello all,

I want to debate about the fact that R/ER cannot relock anymore which weaken pretty hard the missiles now. Sparrows can relock, R77(before pitbull) can relock but why the ER can not anymore ? 

[okopanja]

An interesting question...

Still it would be interesting to learn the technical backgrounds in all of these cases.

[Spurts]

Pretty sure nothing should be able to relock.  A Fox-3 might go pitbull, a Fox-2 or 3 might have a HOJ function, but a lost radar lock completely means a trashed missile, you cannot re-lock in real life.

[GGTharos]

Each missile is tuned to a specific guidance channel.   Once the lock drops the radar abandons this channel - it doesn't know that the same target you locked again is the same.  The way to guard against this is radar memory modes, attempting to recover that lock - but it that fails it's done.

Edited April 15, 2023 by GGTharos

[okopanja]

8 hours ago, GGTharos said:

Each missile is tuned to a specific guidance channel.   Once the lock drops the radar abandons this channel - it doesn't know that the same target you locked again is the same.  The way to guard against this is radar memory modes, attempting to recover that lock - but it that fails it's done.

So this applies to AIM-7s and AIM-120s as well?

Edited April 15, 2023 by okopanja

[GGTharos]

AIM-7's are tuned to a specific channel as well (otherwise you'd have trouble guiding more than one on the same target) and AIM-120's are tuned to a specific m-link as well deconfliction between missiles own active radars.

Not sure what FLOOD does exactly, but given that it will function as a backup mode in case of dropped lock I expect it repeats the expected STT signal/channel that the last launched missile was tuned to (n/a DCS of course)

Edited April 15, 2023 by GGTharos

[draconus]

On 4/15/2023 at 12:03 PM, okopanja said:

So this applies to AIM-7s and AIM-120s as well?

This is how FLOOD works for F-14:

https://www.heatblur.se/F-14Manual/weapons.html#boresight-mode

Afair F-15 should have similar possibility.

[okopanja]

24 minutes ago, draconus said:

This is how FLOOD works for F-14:

https://www.heatblur.se/F-14Manual/weapons.html#boresight-mode

Afair F-15 should have similar possibility.

I think this is not the same use case. We are talking about following use case for SARH missiles:

1. launch in STT with intention of hitting specific target
2. loose lock for whatever reason (e.g. notch)
3. re-lock in STT the target once the conditions permit
4. provided that the seeker can still catch reflections resume guidance toward target locked under 3

So not really switching toward strongest return...

 

[NuII]

 

[okopanja]

On 4/16/2023 at 11:06 PM, Бойовий Сокіл said:

Flood is indeed different. But the R-27 needs radiocorrection to constantly update the gates for the seeker and point it in the right direction. When you drop a lock the interval of illumination and radio correction is broken/lost and there is no way to pick it back up again without some inherent memory. 

See below. (Use online image translator to understand)

Thanks for sharing this. I am aware of these lectures in form PPTs floating around, sadly often google translated into techno gibberish.

So from this Ukrainian text I got a bit better translation, which indicates that side lobs are used to prime the missile during launch sequence (3-4 years later google translate is getting better, but still far from perfect). Other than that I did not quite understand how the updates really worked. E.g. timing and what the increments really applied to.

I am pretty sure I would have asked professor additional questions, but perhaps students had access to more comprehensive material.

[AeriaGloria]

On 4/16/2023 at 2:06 PM, Бойовий Сокіл said:

Flood is indeed different. But the R-27 needs radiocorrection to constantly update the gates for the seeker and point it in the right direction. When you drop a lock the interval of illumination and radio correction is broken/lost and there is no way to pick it back up again without some inherent memory. 

See below. (Use online image translator to understand)

Is this saying that memory mode for the missile is 30.72 ms? Less then 5% of a second?

[okopanja]

5 minutes ago, AeriaGloria said:

Is this saying that memory mode for the missile is 30.72 ms? Less then 5% of a second?

No, if I got it right during the DL guidance, missiles receives updates, the updates are used to extrapolate path.

[AeriaGloria]

6 minutes ago, Бойовий Сокіл said:

Does not specifically say this is a memory mode, just that between the illumination and radiocorrection phases which are ~31ms the target tracking is being done via extrapolation. This is related to the radar itself.

 

3 minutes ago, okopanja said:

No, if I got it right during the DL guidance, missiles receives updates, the updates are used to extrapolate path.

Got it, makes sense 

[GGTharos]

The 31ms is basically the interval into which you must shove all desired signal emissions etc.  The memory mode (STT recovery mode, whatever) will last much longer; I don't know how it's done on the flanker, on the eagle the radar goes through several attempts to recover the track that can potentially last 10+ seconds.  This time is reduced the closer the target is, where I believe inside some 10nm it's as low as 3 seconds.

In DCS you get 4 seconds overall.

[BBCRF3]

В 21.04.2023 в 23:13, GGTharos сказал:

31 мс - это, по сути, интервал, в который вы должны поместить все желаемые выбросы сигнала и т.д. Режим памяти (STT recovery mode, что угодно) продлится гораздо дольше; Я не знаю, как это делается на flanker, на eagle радар предпринимает несколько попыток восстановить трек, которые потенциально могут длиться более 10 секунд. Это время уменьшается по мере приближения к цели, где, я полагаю, в пределах 10 нм оно составляет всего 3 секунды.

В DCS вы получаете в общей сложности 4 секунды.

On the flanker, the radar is also going to restore the capture and it will last not 4 seconds as you wrote, but much longer

[GGTharos]

In DCS it's 4 seconds.

[NuII]

As far as I understand, 27ER is guided with radio correction at first, then within like 20 km from target, plane irradiate the target to precisely guide it. Multiple questions : 

1 : Why there is a launch warning at missile launch beyond 20 km ?

Maybe USA technology managed to dissociate the waves between STT and STT + Radio Corrections. Ok fine. 

2 : Why we cannot relock while guiding missiles through radio corrections and before precise guidings ? 

Because DCS do not simulate this mechanics (Radio correction + STT final guidance). Ok fine.

3 : Why Su 27 / MiG 29 cannot guide through radio correction in TWS ? 

4 : Why Russia is still using R-27ER while facing Fox 3 generations ?

I want to believe that russian Fox 1s are working like AMRAAMS. But instead of active radar inside the missile, it is the plane's radar emiting radiations on target and passive radar (inside missile) receiving and tracking the returns on final stage. So it is guided at first stage like a Fox 3 and within 15 -20 km from target it switches to SARH.

Can someone enlight me more about this please ? Especially the R-27. Compare to real life stories, game mechanics. Lets just talk about it.

I am here to debate, increase everyones knowledges about russian SARH missiles with scientific support, mathematical exemples, physics etc. Say it if I am wrong, no worries.

 

 

Edited November 13, 2023 by NuII

[okopanja]

1.

6 minutes ago, NuII said:

Maybe USA technology managed to dissociate the waves between STT and STT + Radio Corrections. Ok fine. 

Not really a problem when you gain access to documentation and you know where to look for and you happen to poses the electronic base 2 gens more advanced than opponent.

https://en.wikipedia.org/wiki/Adolf_Tolkachev

2.

11 minutes ago, NuII said:

2 : Why we cannot relock while guiding missiles through radio corrections and before precise guidings ? 

Because DCS do not simulate this mechanics (Radio correction + STT final guidance). Ok fine.

Su-27SK manual explicitly states inability to relock. Apparently the missile is primed before actual launch through main radar's side lobs. If this is true, on relock it is not possible to synchronize missile anymore.

3.

13 minutes ago, NuII said:

3 : Why Su 27 / MiG 29 cannot guide through radio correction in TWS ? 

You can use TWS2 mode with Mig-29С but, upon launch the target it will switch to something akin to the DTT with addition of triggering the RWR warnings. I asked this some time ago and did not get straight answer, but perhaps another case of point 1?

4.

15 minutes ago, NuII said:

4 : Why Russia is still using R-27ER while facing Fox 3 generations ?

Comparing the radar equation results between host radar and missile seeker on one side and active missile radar on other side would probably show the advantage of second variant (not to mention the benefits of having more freedom to stay out of range, or network-centric tactics). Also note that limitation of R-27ER range, does not come from the engine, but rather from the same power generator as used on R-27R, which limits operation to a maximum of 60 seconds.

It should be noticed that certain slides on radar operation of dubious quality circulate around. The translations into English largely amount to techno gibberish.

Also note that we are talking about early 80s tech vs late 90s up to 2006-2008 on the other side. E.g. during this long period 10+ generations of CPUs did proliferate. We are talking about having limited resources of e.g. F-15C/Flanker radar computers able to display only simple shapes on HUD/MFD compared to modern stuff (15-17 years compared to nowadays).

[BBCRF3]

6 часов назад, GGTharos сказал:

В DCS это занимает 4 секунды.

Wrong. There is a lot that concerns the Flankers is not implemented correctly

2 часа назад, NuII сказал:

Почему Су 27 / МиГ 29 не могут осуществлять радиокоррекцию в TWS?

Because it's not a Cassegrain antenna.TWS is able to MiG-31 if we talk about the planes of the 80s.

2 часа назад, NuII сказал:

Почему Россия все еще использует R-27ER , столкнувшись с Fox 3 поколения?

[BBCRF3]

2 часа назад, NuII сказал:

Почему при запуске ракеты на расстояние более 20 км появляется предупреждение о запуске ?

Because the radar switches to a different mode

[Ramius007]

all SARH missiles are just obsolete, only planes that use them are those with abondoned modernization programs, and ones that can carry them, and game reflect this preetty good I would say, even if as SARH R-27ET is very good missile, maybe not very accurate but platforms carrying it, can carry a lot of missiles, so spamming is fine. Problem is it's very good missile of the past. OTOH, guess its extremaly hard to find data, but "dead hand" HOJ is most deadly feature of R27ET, so many killed wingmans and even myself by not turning of ECM in time. I think Anti radar/home on jam kind of weapons in video games, DCS sadly included, have those misslies overperform GREATLY compered to RL, guess for usual gamer, even DCS hardcore, firing 10 missiles to hit 1 or 2 times would be dissaointed.

Edited November 13, 2023 by Ramius007

[draconus]

4 minutes ago, Ramius007 said:

R27ET

It's IR guided missile, so no SARH and no HOJ possibility here.

Edited November 13, 2023 by draconus

[Ramius007]

21 minutes ago, draconus said:

It's IR guided missile, so no SARH and no HOJ possibility here.

 

I meant ER ofc. ET works preety well, it's very situational but has it's use, even if flares separation is terrible

Edited November 13, 2023 by Ramius007

[GGTharos]

1 hour ago, Ramius007 said:

I think Anti radar/home on jam kind of weapons in video games, DCS sadly included, have those misslies overperform GREATLY compered to RL, guess for usual gamer, even DCS hardcore, firing 10 missiles to hit 1 or 2 times would be dissaointed.

 

HoJ is simply not represented correctly, and neither are the jammers.  There's no 'over/under' performing here, it's just incorrect in concept and operation.

Edited November 13, 2023 by GGTharos

[Ramius007]

1 hour ago, GGTharos said:

HoJ is simply not represented correctly, and neither are the jammers.  There's no 'over/under' performing here, it's just incorrect in concept and operation.

 

It's represented very correctly, issue is bigger, RWR and overall all passive detection systems are super accurate in DCS, so ARM's are super effective, HOJ super effective, incoming missile range very accurate, even if simplified model it works, just lack of variance put in equtation seem to be wrong, but again, I can see drama coming with adjusting this to realistic settings  As for ECM, it's difficult, everything is classified, We can live with this very simple model that function in a way to givs us more time before enemy get a lock. Things like ECM efficiency vs missiles would be impossible to represent, due lack of data, maybe this is possible for 60/70's era planes, but it's big maybe, everytihng else is just anecdotal knowladge.

Edited November 13, 2023 by Ramius007