Flood Mode

[S77th-GOYA]

I just noticed that a Sparrow fired in flood mode gives a launch warning to the target a/c. Is that correct? It seems I remember that it shouldn't, but I just checked the 1.1 manual and it doesn't say anything about it.

[D-Scythe]

It should, AFAIK. The APG-63 would be using "guidance" PRFs.

 

A better question to ask would be why an AMRAAM launch with SST would give a launch warning, if TWS does not. Since the AIM-120 doesn't need guidance from the APG-63, just target data transmitted through the datalink (which shouldn't be picked up, I think), I see no reason why the AIM-120 would give the target a launch warning with SST, although there should be a lock warning.

[S77th-GOYA]

As I understand it, the launch warning comes from the radar switching from a normal STT lock to guidance mode, so the launch warning would be heard from a 120 or a 7. But in flood mode the 7 is semi-active off the rail and just homes on the strongest RCS and the APG just illuminates a large area without a lock. That illumination is all that the target should see/hear, unless I am wrong.

 

Wher the launch warning comes from with the 120 fired maddog should be the 120's own lock signature, I'm guessing. But that's a good question too.

 

edit: the 120 does need guidance from the 15's radar unless it is fired maddog.

[GGTharos]

D-Scythe, I don't see why you think the radar wouldn't switch to guidance PRFs as with the 7. I understand that you think it doesn't need to, and I'm not saying I disagree, what I am saying is that it can very easily go either way from what I've seen.

 

GOYA, the difference between FLOOD and a STT - guiding is that in FLOOD the radar antenna doesn't track the target - you point the antenna at the target, thus taking away that automation.

Otherwise, it's -exactly- the same, and should give a launch warning ... however: It should give a launch warning right away, instead of lock-launch, since by definition FLOOD is automatically in guidance PRFs.

Everyone inside the flood pattern should get a launch warning.

[D-Scythe]

As I understand it, the launch warning comes from the radar switching from a normal STT lock to guidance mode, so the launch warning would be heard from a 120 or a 7.

 

But the AIM-120 doesn't need guidance from the radar, at all. It's seeker physically just cannot use the guidance PRFs bouncing off the target like the AIM-7's inverse monopulse seeker can. Furthermore, there is no evidence to suggest the guidance PRFs the radar emits gets better information than "normal" SST PRFs, so the reason that the radar can obtain better information for the AMRAAM seems unlikely.

 

D-Scythe, I don't see why you think the radar wouldn't switch to guidance PRFs as with the 7. I understand that you think it doesn't need to, and I'm not saying I disagree, what I am saying is that it can very easily go either way from what I've seen.

 

Again, the question "why would it switch the guidance PRFs?" is just as legitimate a question. Is it because all other sims do it? Cause otherwise, I see absolutely no reason why it should. The facts so far are:

 

• The AIM-120 cannot use the guidance PRFs at all, cause it doesn't have a SARH-capable seeker
  
• Guidance PRFs have not been documented to provide better target information than SST data in the APG-63, but is rather just a means to illuminate a target for the AIM-7
  

 

Thus, if the missile itself cannot use guidance PRFs, and it also doesn't provide better target information, why would the entire APG-70/F-15 system give itself away early in the game when it can delay it a little bit?

 

GOYA, the difference between FLOOD and a STT - guiding is that in FLOOD the radar antenna doesn't track the target - you point the antenna at the target, thus taking away that automation.

Otherwise, it's -exactly- the same, and should give a launch warning ... however: It should give a launch warning right away, instead of lock-launch, since by definition FLOOD is automatically in guidance PRFs.

Everyone inside the flood pattern should get a launch warning.

 

Yes, exactly. I didn't mention that part, but I think that's how it should work too.

[GGTharos]

Again, the question "why would it switch the guidance PRFs?" is just as legitimate a question. Is it because all other sims do it? Cause otherwise, I see absolutely no reason why it should. The facts so far are:

• The AIM-120 cannot use the guidance PRFs at all, cause it doesn't have a SARH-capable seeker
  
• Guidance PRFs have not been documented to provide better target information than SST data in the APG-63, but is rather just a means to illuminate a target for the AIM-7

Thus, if the missile itself cannot use guidance PRFs, and it also doesn't provide better target information, why would the entire APG-70/F-15 system give itself away early in the game when it can delay it a little bit?

 

Well I guess it's difficult for me to explain why I'm bringing up some dissonant views ... :)

 

Here's the thing: I see no reason for it to do this either, BUT in the past, I've been shown that 'logical reason' doesn't always mesh with the facts. There may be a reason for it to be needed, or it may just be a lock-datalink detection trigger.

 

Either way, if you have no answer to the question or either why it should or why it shouldn't, beyond reasoning, then it actually isn't safe to assume it works either way - that's what I'm trying to say.

 

Yes, exactly. I didn't mention that part, but I think that's how it should work too.

 

Yep, hope that gets modelled proper...you can cruise around and scare people without firing a shot :D

[Pilotasso]

I dont remenber where I read it, but it said basicaly that untill now (with active threat warning) there was no way to tell if a missile was airborne or not unless it becomes active. Usualy the attacking aircraft refrains form swiching to the range of frequencies for guiding just before launch. When it does, the attaked aircraft recieves a warning of the respective PRF's rather than any signal the missile is actualy airborne. Its an assumption, and it leaves a margin for bluff, but then again I have no suficient info on this to be positive.

 

With flood mode, by any logic and in the lack of more declassified information you should get lauch warning when painted in flood mode independently if any missile is airborne or not. Thats of course in the case that the F-15 DOESNT fire the radar automaticaly at the launch only. If the radar is always on from the time you swich Flood mode, by all logic, from the moment you are inside his ilumination circle you should get a launch warning no matter what.

[Trident]

I would think that there is no difference in the emission characteristics of the STT mode when either AMRAAM or Sparrow are used. The AIM-120 may use tracking data from the radar fed to it via datalink instead of homing in on the reflected signal itself, but STT is STT IMHO. Since the AMRAAM was introduced at a later stage I would imagine that it was simply integrated with the radar's existing STT mode. I suppose it would be called differently (SST-ARH or something like that) if it was a new mode?

 

Just my 0,02€ ;)

[tflash]

I would think that there is no difference in the emission characteristics of the STT mode when either AMRAAM or Sparrow are used. The AIM-120 may use tracking data from the radar fed to it via datalink instead of homing in on the reflected signal itself, but STT is STT IMHO. Since the AMRAAM was introduced at a later stage I would imagine that it was simply integrated with the radar's existing STT mode. I suppose it would be called differently (SST-ARH or something like that) if it was a new mode?

 

Just my 0,02€ ;)

 

I agree: at first, the british Tornado F-3's could fire Amraam but did not have the capability to use the datalink to do mid-course updates. This capability has been added only recently. If the Amraam however would not be able to use the bounced PRF, then I cannot understand how the Tornado's would have been able to use the Amraam before they got the update.

[D-Scythe]

I would think that there is no difference in the emission characteristics of the STT mode when either AMRAAM or Sparrow are used. The AIM-120 may use tracking data from the radar fed to it via datalink instead of homing in on the reflected signal itself, but STT is STT IMHO. Since the AMRAAM was introduced at a later stage I would imagine that it was simply integrated with the radar's existing STT mode. I suppose it would be called differently (SST-ARH or something like that) if it was a new mode?

 

Just my 0,02€ ;)

 

Sounds good, except one thing: there are actually two SST modes, so to speak. One for radar "lock", another for radar missile "launch." The latter uses special guidance PRFs to illuminate the target for an SARH missile.

 

The target's RWR gives a warning for both types of SSTs. So take an F-15 firing a Sparrow: the target will first get a radar lock warning, then a missile launch warning.

 

My reasoning is that when an F-15 fires an AIM-120 in SST, the target should only receive the radar lock warning but not the missile launch warning, because the AIM-120, from what we know, does not use the "guidance" SST.

 

I agree: at first, the british Tornado F-3's could fire Amraam but did not have the capability to use the datalink to do mid-course updates. This capability has been added only recently. If the Amraam however would not be able to use the bounced PRF, then I cannot understand how the Tornado's would have been able to use the Amraam before they got the update.

 

The Tornado F3 could still use AMRAAM because its radar can transfer data to the missile BEFORE the AMRAAM was launched. Once the AIM-120 was away, however, it flew out to a point/location the Tornado's computers told it too prior to launch to acquire the target with its own radar.

 

The problem was that the Tornado F3 initially was not capable of transferring target data to the AIM-120 AFTER missile launch, and since the target is likely to be manuevering, the initial AMRAAM activation point could easily become outdated and effectively useless.

 

For example, if a Tornado ADV and a MiG-29 were 30nm beak-to-beak, and the ADV launches an AMRAAM, the Tornado's computers would tell the AIM-120 to fly 20 nm straight in front of the Tornado to turn on its radar and acquire the MiG. However, a few seconds after missile launch, the MiG gets a warning and beams the Tornado, moving 90 degrees away from its original flight path. The AIM-120, however, would still think the MiG-29 was still flying head on (which it isn't anymore), and will turn on its radar to find that the MIG isn't there anymore.

 

So technically, the Tornado was NOT capable of using AIM-120 in BVR scenarios except against cruise missiles. And the AIM-120 definitely *CANNOT* use guidance PRFs to home in on a target like a SARH missile can. AFAIK, it has no such capability whatsoever (from publically released data, of course) ;)

 

Either way, if you have no answer to the question or either why it should or why it shouldn't, beyond reasoning, then it actually isn't safe to assume it works either way - that's what I'm trying to say.

 

Then by this logic, most of the ECM/ECCM stuff, missile performance, and other sensitive stuff would be better off not modelled? There are many things we don't have answers for, but if proper reasoning or drawing conclusions from information we already know can't cut it, then what will? That's just my line of thinking I guess - feel free to call me a nut ;)

[GGTharos]

Yeah, you're a nut ;) My point is, it's already modelled one way, and you can't really tell if its right or wrong, so why change it? ;)

[D-Scythe]

Yeah, you're a nut ;) My point is, it's already modelled one way, and you can't really tell if its right or wrong, so why change it? ;)

 

Well, I suppose there are bigger things to worry about :icon_axe:

[GGTharos]

Like missile seeker modelling! *cough*

[Prophet_169th]

The target's RWR gives a warning for both types of SSTs. So take an F-15 firing a Sparrow: the target will first get a radar lock warning, then a missile launch warning.

 

My reasoning is that when an F-15 fires an AIM-120 in SST, the target should only receive the radar lock warning but not the missile launch warning, because the AIM-120, from what we know, does not use the "guidance" SST.

 

The AIM-120 may not use the "guidance" STT, but does that mean that the F15 radar still doesnt? It is dependant on the radar not the missle correct?

[GGTharos]

That's what I'm saying, but D-Scythe makes a valid point also. BUt therein lies the problem.

 

For example, it has been originally assumed that the R-27ET used a datalink - after all, it makes sense, doesn't it?

[D-Scythe]

For example, it has been originally assumed that the R-27ET used a datalink - after all, it makes sense, doesn't it?

 

Yes, it does, but hasn't it been proven that the R-27ET cannot use the datalink? ;) I don't know the specifics, but maybe Alfa does.

 

In this case, there is no information (yet) that suggests the AIM-120 does give a missile launch warning, or more specifically, that the APG-63 switches to guidance PRFs when a Slammer is launched in ANY radar mode.