reported AIM-120C losing targets easily for chaff even at close ranges

[DCS FIGHTER PILOT]

2 hours ago, Csgo GE oh yeah said:

Is it ? From my understanding they use their own chaff value (it was better than the amraam even before the change), and the 54 does not suffer from the ECM thing ?
Or am i wrong 

 The Aim-54 is even more easily spoofed by chaff than the Aim-120. This makes sense seeing as how it’s an older missile but as I have mentioned, the 120 currently eats chaff for breakfast while the Aim-54 eats it for breakfast, lunch, and dinner.

Edited February 7, 2021 by DCS FIGHTER PILOT

[Csgo GE oh yeah]

I honestly don't think so. 

1) At first aim54 really did have a very high chaff-eating number. 

2) Then HB lowered it drastically, it was even better than the aim120 

3) Then ED made this recent change to the aim120
4) I don't think HB did the same for their aim54. 

 

But, i haven't been keeping up with all the changes that much, i could be wrong/incomplete 

Edited February 7, 2021 by Csgo GE oh yeah

[Jack1nthecrack]

6 hours ago, DCS FIGHTER PILOT said:

 The Aim-54 is even more easily spoofed by chaff than the Aim-120. This makes sense seeing as how it’s an older missile but as I have mentioned, the 120 currently eats chaff for breakfast while the Aim-54 eats it for breakfast, lunch, and dinner.

 

The AIM-120 eats chaff for breakfast because you're firing at AI. Do any of the same testing with a real player and the AIM-120 will ignore the chaff 99% of the time. 

[Northstar98]

29 minutes ago, Jack1nthecrack said:

The AIM-120 eats chaff for breakfast because you're firing at AI. Do any of the same testing with a real player and the AIM-120 will ignore the chaff 99% of the time. 

 

Wha? So AI has different chaff effectiveness compared to players? 

[DCS FIGHTER PILOT]

41 minutes ago, Jack1nthecrack said:

The AIM-120 eats chaff for breakfast because you're firing at AI. Do any of the same testing with a real player and the AIM-120 will ignore the chaff 99% of the time. 

I’m afraid that is not the case at all. Just today, I fired an AMRAAM at a human target at 45k ft from underneath him and the thing got decoyed by the chaff. In terms of the AI, it’s nearly impossible to kill them with ARH missiles because they know how to perfectly exploit the current bug.

Edited February 7, 2021 by DCS FIGHTER PILOT

[dundun92]

34 minutes ago, Northstar98 said:

 

Wha? So AI has different chaff effectiveness compared to players? 

pretty sure its not AI, but rather SP vs MP.

[Teknetinium]

1 hour ago, Jack1nthecrack said:

The AIM-120 eats chaff for breakfast because you're firing at AI. Do any of the same testing with a real player and the AIM-120 will ignore the chaff 99% of the time. 

Sounds about right. 

[Tippis]

4 hours ago, Csgo GE oh yeah said:

I honestly don't think so. 

1) At first aim54 really did have a very high chaff-eating number. 

2) Then HB lowered it drastically, it was even better than the aim120 

3) Then ED made this recent change to the aim120
4) I don't think HB did the same for their aim54. 

 

But, i haven't been keeping up with all the changes that much, i could be wrong/incomplete

Just based on the database stats…

 

Missiles have a “counter countermeasure factor” (ccm_k0) that modifies their probability to get spoofed. The lower the number, the lower the chance that countermeasures will effect them. By default, a factor of 1 means they have standard probability; a factor of 2 means they are twice as likely to eat CM as the standard; a factor of 0 means the will always succeed at countering the countermeasures.

 

The stats for various radar missiles at the moment are:

• AIM-7M: 1

• AIM-7E, AIM-7F: 3

• AIM-7MH: 0.5

• AIM-54, AIM-120B, AIM-120C, R-27R, R-27ER, R-77: undefined (defaults to 1) edited; see below for AIM-120s

• PL-12 / SD-10: 0.12

• AIM-54A Mk47, AIM-54A Mk60: 0.3

• AIM-54C Mk47: 0.25

Edited February 7, 2021 by Tippis

[Taz1004]

4 minutes ago, Tippis said:

• AIM-54, AIM-120B, AIM-120C, R-27R, R-27ER, R-77: undefined (defaults to 1)

 

Does that mean you can enter that value for those missiles to change it?

[Csgo GE oh yeah]

Yeah so the aim54 MK60 (all that anyone ever uses) is almost 4x more resistant to chaff than a 120C . :d 

Edited February 7, 2021 by Csgo GE oh yeah

[Tippis]

1 minute ago, Taz1004 said:

 

Does that mean you can enter that value for those missiles to change it?

I haven't tried it, and I have no idea how the data structure and entry initialisation would handle it…

 

…but in principle, yes, probably.

[Northstar98]

1 minute ago, Csgo GE oh yeah said:

Yeah so the aim54 MK60 (all that anyone ever uses) is almost 4x more resistant to chaff than a 120C . :d 

 

It's closer to 3x...

 

The AIM-7MH is 2x more resistant, and the PL-12/SD-10 is over 8x as resistant...

 

It's more the case that EDs ARH missiles need some work, as well as the whole EW/ECCM thing in general... It's quite clear that it's basically borked right now.

[dundun92]

The ccm_k0s are a bit misleading rn, as the missiles are using different chaff models. AMRAAM/SD-10 (maybe sparrow?) are on the new chaff model, while all the others are on the old model, so you cant really compare ccm_k0s across the board. And the AIM-120B/C do have CCM_k0s, theyre in the missiles_table.lua. Its

[Tippis]

10 minutes ago, dundun92 said:

The ccm_k0s are a bit misleading rn, as the missiles are using different chaff models. AMRAAM/SD-10 (maybe sparrow?) are on the new chaff model, while all the others are on the old model, so you cant really compare ccm_k0s across the board. And the AIM-120B/C do have CCM_k0s, theyre in the missiles_table.lua. Its

Oh! Nice find.

 

So, redacted:

• AIM-120B: 0.2

• AIM-120C: 0.1

 

Not quite as bad… except it might be depending on how old and new systems relate to each other. Clarity!

Edited February 7, 2021 by Tippis

[Northstar98]

There you go @Csgo GE oh yeah the AIM-54 are 2-3x more likely to go for chaff than the AIM-120s, it's just presumably borked EW making them go for chaff.

[Csgo GE oh yeah]

Indeed because at this moment aim120 is definately the chaff eating king it seems :d 
nom nom nom 

[captain_dalan]

On 2/4/2021 at 7:53 PM, GGTharos said:

 

6 degrees for most RF guided AAMs.  Yes, chaff will be out of FoV before it can be effective realistically inside certain ranges, but at the same time that's not how chaff in DCS has ever worked.   ED has a bunch of considerations built into the chaff rejection algorithm, perhaps they should add distance to target to the look down, aspect and # of decoys in FoV considerations.

Good ideas there

[Arctic Fox]

I did some testing by playing around with the ccm_k0 values of the AIM-120C and testing it against a closing ace-level Flogger at high altitude yesterday. According to notes on some of the missiles, a value of 0 should represent perfect countermeasure rejection capability while a value of 1 represents "medium" countermeasure rejection. Indeed, as Tippis noted above, the way missile seekers are coded in the Lua has the more advanced missiles with CCM values progressively closer to 0, and most missiles in the game fall between 0 and 1.

 

When I tested values between 0 and 1, which is where most missiles in DCS fall, I could not discern any practical difference in countermeasure rejection. At a value of 0, which should supposedly make the missile immune to chaff, as well as values like 0.01 and 0.000000000001, the missiles still went dumb against chaff in well over 95% of my tests. Things were the same when I tried a value of 1 and anything in between.

 

Following this, I tried arbitrarily larger values. Setting the values to 10, 50 and 100 still had the missiles miss for chaff almost every time, but the missiles seemed to gain the ability to reacquire the target after falling for chaff. At 1000 and 10000000000, the missiles would flip-flop between tracking chaff but ultimately reacquire and either get very close or hit the target almost every time (though a factor affecting affecting this is that sometimes the AI would stop notching when it thinks the missile went for chaff).

 

I haven't tested the effects on IR and SARH missiles, but I strongly suspect that countermeasure rejection might not currently function correctly in DCS as a whole, at least with respect to the values found in the Lua. The values which should give perfect countermeasure resistance clearly don't while the values that should give lower resistance seem to give the missile a progressively higher probability of kill, though the behaviour at those values is really wonky, with the missiles constantly shifting between tracking the chaff and the target.

 

I'm attaching several tracks of shots at ccm_k0 values at 0 (which should be considered typical of all the shots I made at values between 0 and 1), 10, 50, 100 and 1000.

AIM-120C CCM Test 1000 N1.trk AIM-120C CCM Test 1000 N2.trk AIM-120C CCM Test 1000 N3.trk AIM-120C CCM Test 1000 N4.trk AIM-120C CCM Test 0.trk AIM-120C CCM Test 10 N1.trk AIM-120C CCM Test 10 N2.trk AIM-120C CCM Test 10 N3.trk AIM-120C CCM Test 50 N1.trk AIM-120C CCM Test 50 N2.trk AIM-120C CCM Test 50 N3.trk AIM-120C CCM Test 100 N1.trk AIM-120C CCM Test 100 N2.trk

[captain_dalan]

On 2/6/2021 at 11:35 AM, Nealius said:

A few months ago chaff resistance was more realistic until ED nerfed it into its current state, for reasons unknown. 

 

On 2/6/2021 at 2:38 PM, GGTharos said:

No, it was because some people complained that it was different from before.   Of course they continue to complain that R-27s are too sensitive at the same time.

Indeed, people keep screaming for a change, and when a change finally arrives, people scream about why the change was made. Or why it's not implemented on ALL sides in ONE moment. Too much bad blood and too much baggage i suspect.

Edited February 8, 2021 by captain_dalan

[GGTharos]

According to @Arctic Fox above it appears that we may have a bona-fide bug.

[dundun92]

@Arctic Foxgreat find, have you tested this with a freind in MP? SP ccm resistance has been wonky for a while, but MP ccm is different from SP ccm for some reason. Also, hace you tested this with any missiles on the old chaff model (ER, R-77, etc), so we can rule out this being simply due to the new chaff model?

[Arctic Fox]

I've not had a chance to try it either in MP or with other weapons, no. It might just be a problem with only the new model. Is there a source somewhere detailing which weapons were changed?

[dundun92]

1 hour ago, Arctic Fox said:

I've not had a chance to try it either in MP or with other weapons, no. It might just be a problem with only the new model. Is there a source somewhere detailing which weapons were changed?

The patchnotes indicate that only the AIM-120 (and SD-10 since it uses the AIM-120 scheme) uses the new chaff model, AIM-54 used to but HB reverted to the old chaff model. So anything but an AMRAAM/SD-10 works fine, the R-77 would probably be the best to test though, since stuff like the SARH chaff bug arent factored in

[Katalan]

Having read all this post (and tested today 6 AIM-120C (2 hits, 4 misses -all misses with strange behavior in tacview-), we can say actually AIM-7 coulf be better option to carry than AMRAAM? 

[GGTharos]

You could have tested some AIM-7's to determine that on the spot, but it's prudent to fix your test scenario and take 100 shots, not 6

Edited February 8, 2021 by GGTharos