AIM-120 seeker lock and AIM-7 Flood mode question

[Beamscanner]

1. Is it possible to use the AIM-120 seeker to lock targets prior to launch IRL? similar to the AIM-9..

 

2. How does a targets RWR know when a missile has been launched in flood mode? AFAIK the emission is unchanged when a AIM-7 is launched in flood mode..

Edited February 1, 2016 by Beamscanner

[red_coreSix]

1. Don't know but I don't see why it wouldn't be possible.

2. AFAIK you get a launch warning as soon as your aircraft is painted with flood emissions.

[Beamscanner]

Last time i tested it in game the target got a lock tone prior to launch, and then a missile warning when the missile launches..

 

Which of course makes no sense.

[codefox]

Flood mode give a launch warning some time ago. It appears to have changed however. I don't know whether this has been done intentional or by mistake, but flood mode only gives a lock warning since a few updates ago.

[ShuRugal]

1. Is it possible to use the AIM-120 seeker to lock targets prior to launch IRL? similar to the AIM-9..

 

2. How does a targets RWR know when a missile has been launched in flood mode? AFAIK the emission is unchanged when a AIM-7 is launched in flood mode..

 

#1 should not be possible. The AIM-9 can do this because it looks for actively radiating targets. The AIM-120 (and all other radar-guided missiles) look for the reflection of the launching aircraft's radar illumination signal. This requires the launching AC radar to be in guidance mode, the target to be locked by the launching AC, and the missile to be tuned to the frequency and code of the guiding radar. It is my understand (based on a few informative posts made by GGTharos in the recent budy-guiding thread) that the last step is performed when the pilot commands the missile to launch.

 

For #2, radar in game is largely a set of scripted states. There is (currently) no actual simulation of radar signals. The RWR, consequently, behaves oddly. FLOOD mode should trigger the RWR of every aircraft illuminated by it either as a STT lock or as a missile-guidance lock. As Codefox said, it used to behave this way.

[red_coreSix]

You do know that the AMRAAM is active right? Meaning it has its own seeker for terminal guidance...

[PiedDroit]

1- RL description of the AIM-120 says it can be launched in pitbull mode (i.e. locked and active) if the distance is short enough, so, yes. How it is modelled is another question I can't answer.

However, if you mean that only the missile's radar is used for lock, in theory, yes.

Edited February 1, 2016 by PiedDroit

[GGTharos]

1. Is it possible to use the AIM-120 seeker to lock targets prior to launch IRL? similar to the AIM-9..

 

2. How does a targets RWR know when a missile has been launched in flood mode? AFAIK the emission is unchanged when a AIM-7 is launched in flood mode..

 

1). Not a chance, you'd be riding risking your missile's batteries dry while it's on the pylon IMHO. AFAIK the system is programmed to activate the on-board radar on when the fly-out point is reached, or if the missile is mad-dogged (in which case, your fly-out point is 'off the rail' :) )

 

@ShuRugal: Radar tuning applies to SARH, but not ARH missiles. On the other hand, it's very useful to upload datalink information to the ARH: which channel is the M-link being transmitted on, what's your missile ID, here's some data with the target location and vector and possibly indicating whether the data has gone bad due to ECM or other reasons.

 

2) It doesn't. I'll report it again whenever I get to it :-) It should either never report a launch warning or always report a launch warning. Given that it's supposed to transmit the 'tickle' that HSTT provides, I'd lean on the side of producing a launch warning.

Edited February 1, 2016 by GGTharos

[Frostie]

1- RL description of the AIM-120 says it can be launched in pitbull mode (i.e. locked and active) if the distance is short enough, so, yes. How it is modelled is another question I can't answer.

However, if you mean that only the missile's radar is used for lock, in theory, yes.

 

I believe this is fired bore mode with no radar acquisition, the target is visually placed in the circle and when launched the AMRAAM goes active off the rail. This has a probability of friendly fire and also of not tracking anything at all.

[GGTharos]

That's how it works, and its purpose is the same as FLOOD for the Sparrow.

 

The missile has a pretty good chance of tracking anything that's in the VISUAL circle, which is bad news for well, anyone who's in it.

 

On the other hand, the missile has to choose the target for itself, and good application of chaff might see it going for the wrong target - this sort of thing isn't modeled for any missile in DCS unfortunately (choosing chaff based on larger signature is, but always in the context of 'switching from target to decoy')

[Oceandar]

So in flood mode Aim-7 is pretty much fire and forget ? Am I right ?

 

Only the dead have seen the end of war - Plato

[GGTharos]

No, in FLOOD mode you must keep the target illuminated by keeping it inside the FLOOD reference circle.

[Oceandar]

Aahh...ok thanks GG

 

Only the dead have seen the end of war - Plato

[ShuRugal]

 

@ShuRugal: Radar tuning applies to SARH, but not ARH missiles. On the other hand, it's very useful to upload datalink information to the ARH: which channel is the M-link being transmitted on, what's your missile ID, here's some data with the target location and vector and possibly indicating whether the data has gone bad due to ECM or other reasons.

 

Ah, I was under the impression that until reaching terminal guidance, an ARH could be guided as SARH, if launched in STT instead of TWS.

 

 

Also, doesn't the AIM-120 (and other missiles) use a molten-salt battery? Would it even be possible to power the radar without the motor burning?

 

1- RL description of the AIM-120 says it can be launched in pitbull mode (i.e. locked and active)

 

What you are referring to is a mad-dog launch. In this mode, the missile has no target info at all, and picks up the first thing it sees after leaving the rail.

[GGTharos]

Ah, I was under the impression that until reaching terminal guidance, an ARH could be guided as SARH, if launched in STT instead of TWS.

 

 

Also, doesn't the AIM-120 (and other missiles) use a molten-salt battery? Would it even be possible to power the radar without the motor burning?

 

Never SARH AFAIK, though there was some talk about Phoenix doing that. Not convinced that was accurate.

 

The slammer runs inertial with target updated from mlink until the flyout point, then it goes active and uses it's own radar and mlink to sort the correct target etc. STT is more accurate obviously since the area of uncertainty is reduced to the launcher's radar cell resolution, as well as timely heading changes etc.

 

As for the batteries, all I know is that the 120 has 4 big ones :-)

Also you can power the radar from an external sources for testing, but I figure this is a maintenance mode possibly requiring the removal of the seeker from the missile.

[Sweep]

Never SARH AFAIK, though there was some talk about Phoenix doing that. Not convinced that was accurate.

 

The slammer runs inertial with target updated from mlink until the flyout point, then it goes active and uses it's own radar and mlink to sort the correct target etc. STT is more accurate obviously since the area of uncertainty is reduced to the launcher's radar cell resolution, as well as timely heading changes etc.

 

As for the batteries, all I know is that the 120 has 4 big ones :-)

Also you can power the radar from an external sources for testing, but I figure this is a maintenance mode possibly requiring the removal of the seeker from the missile.

 

Isn't the -54 SARH midcourse to terminal ARH?

[GGTharos]

That's what's written, but who knows what it actually means.

[Beamscanner]

Isn't the -54 SARH midcourse to terminal ARH?

 

I doubt the -54 seeker would be sensitive enough to even see a reflected illumination from it's intended launch range.. Also, the AWG-9/-54 combo can engage 6 targets at long range simultaneously, and there is no way that the AWG-9 (a mechanically scanned planar array) can effectively illuminate 6 separate targets at once..

 

 

@GGtharos

I assumed that the AIM-120 seeker could be fed power in a similar way as the AIM-9..

 

I realize that this would be dangerous because of the seekers lack of IFF, but it seems like something that is doable. It would certainly be a great trick for fooling enemy RWRs..

Edited February 3, 2016 by Beamscanner

[Pikey]

Does anyone know why and when the shoot lights come on in FLOOD mode? (They do)

[GGTharos]

@Beamscanner: Not bad assumption but doesn't appear to be mentioned at all. It seems the seeker is powered only by the internal battery, and it may actually draw more power than you could provide on the pylon. There could also be cooling limitations.

 

@Pikey: They shouldn't, but its a minor thing.

[Frostie]

I realize that this would be dangerous because of the seekers lack of IFF, but it seems like something that is doable. It would certainly be a great trick for fooling enemy RWRs..

 

I knew this was the intention from the initial post, i'm not sure on its benefits in the real world but I don't think this would be beneficial in game. If you mean to trick a Russian bandit you're chasing then this would soon become common knowledge with a minimum strength lock on his six meaning it can only be an ARH trick, as aircraft radars can't lock your six much beyond 2bars of strength. So for this to be effective in making the bandit think someone had locked his 6 at range it would require the AMRAAM to lock on at something like 2-3km, which is easily the kill zone for an ARH anyway. Or maybe you meant something else.

[Seaeagle]

Never SARH AFAIK, though there was some talk about Phoenix doing that. Not convinced that was accurate.

 

I have seen combination of SARH/ARH stated for several missile seekerheads including that of the AIM-54 e.g:

 

http://www.navy.mil/navydata/fact_display.asp?cid=2200&tid=700&ct=2

 

"Guidance system: Semi-active and active radar homing"

 

... not for midcourse guidance(which works as you described), but as an alternative homing method(with STT support)....possibly to extend seeker acquisition range.

[pr1malr8ge]

I have seen combination of SARH/ARH stated for several missile seekerheads including that of the AIM-54 e.g:

 

http://www.navy.mil/navydata/fact_display.asp?cid=2200&tid=700&ct=2

 

"Guidance system: Semi-active and active radar homing"

 

... not for midcourse guidance(which works as you described), but as an alternative homing method(with STT support)....possibly to extend seeker acquisition range.

 

The sarh method is probably refering hoj guidance where the seaker head is not activly pinging a target.

[Beamscanner]

I knew this was the intention from the initial post, i'm not sure on its benefits in the real world but I don't think this would be beneficial in game. If you mean to trick a Russian bandit you're chasing then this would soon become common knowledge with a minimum strength lock on his six meaning it can only be an ARH trick, as aircraft radars can't lock your six much beyond 2bars of strength. So for this to be effective in making the bandit think someone had locked his 6 at range it would require the AMRAAM to lock on at something like 2-3km, which is easily the kill zone for an ARH anyway. Or maybe you meant something else.

 

yeah, but there's a lot of pilots who'd freak out and maneuver regardless of the signal strength. Sure a 51st driver (or whoever on here who would say otherwise) would know better, but many pilots online wouldn't.

 

It would also work pretty well against a head on target to get him/her to defend and lose energy.. Not just in a chase.

 

Remember, a RWR doesnt tell you when a radar has detected you, but tells you if it sees the radars energy and parameters. So, even though the seeker cant detect a target outside of X miles, the RWR would more than likely see the signal at ~4X (a much further range, but really depends on the RWR receiver/antenna setup). The RWR sees a much more powerful signal from the main beam then the tiny reflected signal that traveled round trip back to the seeker.

 

The sarh method is probably refering hoj guidance where the seaker head is not activly pinging a target.

Whatever the case, the AWG-9 radar would only be able to support 1 SARH engagement at a time if it did have that option.. And if doing so, would not be able to provide tracking guidance on any other target during this engagement. The mechanically scanned antenna would have to stay fixated on the target in order to support a SARH missile, and thus could not perform tracking on anyone else. (and thus couldn't provide mid course guidance for the 5 other -54s it's supposed to be able to support at the same time)

Edited February 4, 2016 by Beamscanner

[Seaeagle]

The sarh method is probably refering hoj guidance where the seaker head is not activly pinging a target.

 

No it isn't.

 

HOJ is passive radar homing and has nothing to do with semi-active radar homing(SARH).