reported earlier AIM-120 can still be defeated by barrel rolls at high altitudes

[SchumiF399]

OK, I managed to get a track file from my very first engagement on the GS server with a jamming F/A-18. Both AMRAAMS are what I consider high PK but they miss. The AIM 9X was shot as a last ditch effort, it came closer than the 120s. AMRAAMS are useless against jamming targets at any range!

Server_1_Operation_Urban_Thunder_V7.2.9-20230119-170719.trk

Edited January 20, 2023 by SchumiF399

[Pavlin_33]

On 1/15/2023 at 1:53 AM, Wolf1One said:

I'm flying the F16 on GS and I'm getting my teeth kicked in by FC3 aircraft because the amraam is so bad... It never worked properly but in the past you could at least hit something with it. Nowadays everybody on multiplayer PVP knows how to notch it and render it useless. Being forced to rely on AIM9Xs is frustrating, especially against an aircraft capable of shooting a R27ET from farther away.

Grass is always greener on the other side.

As someone who eats 120s on regular basis I would say it's laser-like, but that's 'cause I fly FC3 mostly. I would suggest, if you own FC3, to try them out and see how easy/diffcult it is to shoot someone down.

P.S. Any radar guided missile can be notched - that's just how PD radar works

[Ghosty141]

Am 21.12.2022 um 16:21 schrieb Маэстро:

Yes, but problems with hitting high-g jaming tagets is intdened and caused by simple fact that missile can not measure closing velocity and range. The only thing to discuss is the level of this "issue".

In falklands tracks targets do not use ECM, so that's not the reason.

Shouldn't the missile be able to burn through ECM after which it doesn't have to use HOJ mode anymore? At least once it comes close enough like in some of the cases above. How is this currently implemented.

Thanks for the insights btw

[Dragon1-1]

Not necessarily, a missile in HOJ is using the radar in passive mode, so it doesn't know if it can burn through or not. If it can remain in HOJ, it will do so until impact. While this type of guidance is less efficient, it provides no warning to the target.

[Ghosty141]

Am 5.2.2023 um 14:23 schrieb Dragon1-1:

Not necessarily, a missile in HOJ is using the radar in passive mode, so it doesn't know if it can burn through or not. If it can remain in HOJ, it will do so until impact. While this type of guidance is less efficient, it provides no warning to the target.

Can you specify with what you mean by "no warning to the target". In the Hornet for example if you don't get a warning, the jammer is not going to emit anything, so the missile wouldn't need to be in HOJ mode. I guess I'm misunderstanding you there.

[Dragon1-1]

HOJ doesn't work with lock-breaking, which is what the Hornet does. It only works with barrage jamming, in which the jammer is always on. As such, a missile in HOJ does not need to emit anything, just home in passively onto the jammer's emissions. It will do it as long as it can, then go active when it can't. Hornet's lock-breaking is a more advanced technique which only denies radar lock, not range in search mode or in TWS, but it does not provide a constant emission source for a HOJ missile to home onto.

[GGTharos]

This is just so wrong.  But it is what DCS does. 

What we could/should have:  Your AAMs aren't built to deal with 'barrage jamming'.   They're built to home in your (or their own) radar signal reflection, and it is what signal that the jammer attempts to mess up.   The DCS hornet doesn't do anything 'advanced', it just takes advantage of a very old behavior in the game.

Pretty much every modern fighter equipped with an SPJ should be capable of this behavior (eg. simultaneous range and angles jamming techniques), but DCS represents none of this.

Instead, it represents all ECM as range jammers alone (which is ok-ish), that jam all radio sources simultaneously (very wrong) and regardless of emitter mode (partially wrong, depends on the jammer).

Similarly, this follows with HoJ being some kind of 'passive' mode (just wrong) when what it is, is your radar and missile trying to frequency-hop or ignore certain pieces of data - similarly with AMRAAM, HoJ is allowing you to launch the missile with last known good data, and not hanging the launch when you say 'shoot' and the ECM invalidates the data.   What the missile tries to do from there on is another story but there's nothing passive about it - the seeker has its own ECCM built in like frequency-hopping, PRF changes, tracking gate and edge manipulation etc.

And of course the more powerful and interesting ECM isn't modeled, ie. ground-bounce of stead Vc jamming (a B-52 can lie to  your radar and tell it that it's going mach 2 ... if you don't notice that yourself, that missile you shoot is going to fly where that aircraft isn't, and you won't get any ECM/HoJ indications either - and that, BTW is why the flanker's IRST exists, not for 'stealth shots').

Edited February 11, 2023 by GGTharos

[Ghosty141]

Am 11.2.2023 um 13:06 schrieb GGTharos:

This is just so wrong.  But it is what DCS does. 

What we could/should have:  Your AAMs aren't built to deal with 'barrage jamming'.   They're built to home in your (or their own) radar signal reflection, and it is what signal that the jammer attempts to mess up.   The DCS hornet doesn't do anything 'advanced', it just takes advantage of a very old behavior in the game.

Pretty much every modern fighter equipped with an SPJ should be capable of this behavior (eg. simultaneous range and angles jamming techniques), but DCS represents none of this.

Instead, it represents all ECM as range jammers alone (which is ok-ish), that jam all radio sources simultaneously (very wrong) and regardless of emitter mode (partially wrong, depends on the jammer).

Similarly, this follows with HoJ being some kind of 'passive' mode (just wrong) when what it is, is your radar and missile trying to frequency-hop or ignore certain pieces of data - similarly with AMRAAM, HoJ is allowing you to launch the missile with last known good data, and not hanging the launch when you say 'shoot' and the ECM invalidates the data.   What the missile tries to do from there on is another story but there's nothing passive about it - the seeker has its own ECCM built in like frequency-hopping, PRF changes, tracking gate and edge manipulation etc.

And of course the more powerful and interesting ECM isn't modeled, ie. ground-bounce of stead Vc jamming (a B-52 can lie to  your radar and tell it that it's going mach 2 ... if you don't notice that yourself, that missile you shoot is going to fly where that aircraft isn't, and you won't get any ECM/HoJ indications either - and that, BTW is why the flanker's IRST exists, not for 'stealth shots').

 

Don't get me wrong I don't doubt this but I'm curious for some sources that can back this up.
The part that I also read is that the missile is way more proactive when it comes to getting "through" the jamming signal and getting the lock than currently modeled in DCS. I personally don't even really mind them not having it implemented yet, I'd just wish some more explanations on what is intended and what is not.

[Pavlin_33]

On 2/14/2023 at 11:00 PM, Ghosty141 said:

Don't get me wrong I don't doubt this but I'm curious for some sources that can back this up.
The part that I also read is that the missile is way more proactive when it comes to getting "through" the jamming signal and getting the lock than currently modeled in DCS. I personally don't even really mind them not having it implemented yet, I'd just wish some more explanations on what is intended and what is not.

Which part do you need the sources for?

[GGTharos]

On 2/14/2023 at 4:00 PM, Ghosty141 said:

Don't get me wrong I don't doubt this but I'm curious for some sources that can back this up.

Possibly, but you'll have to find them and join the dots yourself.  There are some documents and videos discussing radio in general and jamming techniques specifically, and you might find some bits on ECCM.

On 2/14/2023 at 4:00 PM, Ghosty141 said:

The part that I also read is that the missile is way more proactive when it comes to getting "through" the jamming signal and getting the lock than currently modeled in DCS. I personally don't even really mind them not having it implemented yet, I'd just wish some more explanations on what is intended and what is not.

 

So basically what I described?

And just to be clear on the simple understanding of the physics here, the radiated power output of the ECM is going to be higher than the radar reflection from the offending radar, be it from an aircraft or active missile.  In short, there's probably no burn-through and you need other ways to deal with it.

Edited February 17, 2023 by GGTharos

[Sanyo]

So is this a bug or not? From the first ED answers I'm not sure...

[H7142]

Also can ED try this again now that the track system has been improved I highly suspect that track file issues have a role to play here in the inability to replicate.

 

 

[SgtPappy]

This appears to be the same bug, affecting the AIM-120 and the AIM-7M/MH but I've only ever encountered it vs the Mirage. I'm sure it's happening with other aircraft but I've never managed to reproduce it with other planes:

 

AIM-7M/MH examples:

 

[DCS FIGHTER PILOT]

I would also like to point out that if you try this defense against in AMRAAM in another game....... you will almost always end up getting hit. I think part of the problem here in DCS is the proximity fuse does not seem to be working or is not modeled. 

[Night Raid]

vor 2 Stunden schrieb DCS FIGHTER PILOT:

I would also like to point out that if you try this defense against in AMRAAM in another game....... you will almost always end up getting hit. I think part of the problem here in DCS is the proximity fuse does not seem to be working or is not modeled. 

Probelm is, it is modeld but not correctly. In another post they found data that the proxy fuse is about 50 ft round about 15m. BUT Big Newy said and i qote:" I will mention it to the team but it may conflict with other public data. " 

found here: https://forum.dcs.world/topic/316824-aim-120-proximity-fuze-too-low/?do=findComment&comment=5150544

So what i dont understand is that they have the aviable data with 15m proxy fuse that will have a big influence to stop the barrel roll exploit defeat that is going on for years in the Sim. But ED is keeping the 7m (roughly 23feet) for some reason that will not help for some realistic defense manouver.

[DCS FIGHTER PILOT]

Allow me to also point out that this issue does not seem to affect the SD-10 (at least not as severely). 

SD-10 Shot.trk AIM-120B Shot.trk AIM-120C Shot.trk

[Hobel]

vor 5 Stunden schrieb DCS FIGHTER PILOT:

Allow me to also point out that this issue does not seem to affect the SD-10 (at least not as severely). 

SD-10 Shot.trk 233.37 kB · 1 Download AIM-120B Shot.trk 310.79 kB · 1 Download AIM-120C Shot.trk 272.99 kB · 1 Download

The main reason is, among others, the proxy fuze 

Aim120 7m
Sd10a 11m

 

  It's not much but it makes a big difference, I haven't looked at your tracks yet but often the aim120 misses exactly in the areas where an sd10 still explodes.

[SgtPappy]

Adding further to the issues experienced above, the AIM-7s are also being dodged at essentially any altitude by simple barrel rolls + spamming chaff. I've only experienced this with the Mirage but have yet to test other jets. If it is only reproduceable with the Mirage, I'll post it in the M2k forums as well.

Link to tacview (it's too big to attach): https://file.io/eZND4892GFaX

Link to track: https://file.io/Sge770WFtLiB

[Hobel]

vor 32 Minuten schrieb SgtPappy:

Adding further to the issues experienced above, the AIM-7s are also being dodged at essentially any altitude by simple barrel rolls + spamming chaff. I've only experienced this with the Mirage but have yet to test other jets. If it is only reproduceable with the Mirage, I'll post it in the M2k forums as well.

Link to tacview (it's too big to attach): https://file.io/eZND4892GFaX

Link to track: https://file.io/Sge770WFtLiB

M2000 with ECM is basically immune to Fox1 and 3 , so it could also have been a factor here

[SgtPappy]

12 hours ago, Hobel said:

M2000 with ECM is basically immune to Fox1 and 3 , so it could also have been a factor here

Very disappointing to hear. Has it been reported already?

[Tango3B]

12 hours ago, Hobel said:

M2000 with ECM is basically immune to Fox1 and 3 , so it could also have been a factor here

Blinking is part of every modern SPJ. This is certainly no bug RAZBAM has to look at. And by the way, the M2k uses the same SPJ power as the FC3 Su-27 module. The problem actually is how ED chose to model the DCS Aim-120 seeker and how it reacts to any form of jamming. The same goes for the Sparrow, of course. There should be a thorough review of the entire DCS ECM/ECCM system…

[Hobel]

vor 25 Minuten schrieb Tango3B:

Blinking is part of every modern SPJ. This is certainly no bug RAZBAM has to look at. And by the way, the M2k uses the same SPJ power as the FC3 Su-27 module. The problem actually is how ED chose to model the DCS Aim-120 seeker and how it reacts to any form of jamming. The same goes for the Sparrow, of course. There should be a thorough review of the entire DCS ECM/ECCM system…

I would assume that Aim120 and others should also have a burn through so that the closer the missle gets the less effect of ECM.

[SgtPappy]

3 hours ago, Tango3B said:

Blinking is part of every modern SPJ. This is certainly no bug RAZBAM has to look at. And by the way, the M2k uses the same SPJ power as the FC3 Su-27 module. The problem actually is how ED chose to model the DCS Aim-120 seeker and how it reacts to any form of jamming. The same goes for the Sparrow, of course. There should be a thorough review of the entire DCS ECM/ECCM system…

Good point.

To support this, it is well-known that radar guided missiles in DCS have all experienced strange guidance behaviour through the years so it does not surprise me that this is more on ED's side to fix. I recall the F-14 blinking jammer made any radar guided missile fail even WVR at one point. Now, it is the Mirage that manages to take advantage of rolling dodges using ECM and chaff (or so I've noticed thus far, I could be wrong). 

[GGTharos]

This is an issue that everyone has to look at, even just to deal with it on a temporary basis.  There are definitely things that RAZBAM can do.

Edited January 2 by GGTharos

[Notarobot]

Barrel roll exploit is still very much a thing, anything in the works for this? It's been a few years now