Possible massive bug affecting many IR missiles (and possibly radar missiles too)

[Mad_Shell]

@Flappie @Маэстро

I tag you both because that's possibly a very important one.

While doing testing on the Mistral missile, I found out, as I have suspected for some time) that the ccm_k0 parameter has absolutely no effect. For those not aware, lower ccm_k0 means better resistance to countermeasures (flares or chaff, since both IR and radar missiles use this parameter). Even setting ccm_k0 to a value very close to 0, the missile almost always goes for flares. 

So I go check the Igla and FIM92C (stinger) files, and the ccm_k0 is not even present! 

The conclusion is that the ccm_k0 parameter is not used anymore for IR missiles using the new seeker modelling. That leaves the seeker field of view as the only parameter effecting the resistance to countermeasures. Since ED chooses realistic FOV for their missiles (between 2° and 4°), that means that those missiles are modelled as if they haven't ANY algorythm to reject flares. Which is of course not realistic at all, and gives all those missiles a terrible resistance to flares.

I don't know if the radar missiles are also affected, but I think it would be worth to check for those too, especially the ones using the new radar seeker modelling.

[oldcrusty]

Thanks for catching this and possibly finding the cause.

I noticed the same behavior with Aim9x...  it's not my favorite tool anymore :/

[Маэстро]

On 3/12/2023 at 1:47 AM, Mad_Shell said:

@Flappie @Маэстро

I tag you both because that's possibly a very important one.

While doing testing on the Mistral missile, I found out, as I have suspected for some time) that the ccm_k0 parameter has absolutely no effect. For those not aware, lower ccm_k0 means better resistance to countermeasures (flares or chaff, since both IR and radar missiles use this parameter). Even setting ccm_k0 to a value very close to 0, the missile almost always goes for flares. 

So I go check the Igla and FIM92C (stinger) files, and the ccm_k0 is not even present! 

The conclusion is that the ccm_k0 parameter is not used anymore for IR missiles using the new seeker modelling. That leaves the seeker field of view as the only parameter effecting the resistance to countermeasures. Since ED chooses realistic FOV for their missiles (between 2° and 4°), that means that those missiles are modelled as if they haven't ANY algorythm to reject flares. Which is of course not realistic at all, and gives all those missiles a terrible resistance to flares.

I don't know if the radar missiles are also affected, but I think it would be worth to check for those too, especially the ones using the new radar seeker modelling.

Hi! There is no massive issue. There was a problem with reading ccm_k0 value form lua, that is already fixed internally.

Mistral, stinger, igla, mim-72 is the only affected missiles. All they have defalut value of ccm_k0 = 0.5 at the moment(in OB and release version).

[Mad_Shell]

5 hours ago, Маэстро said:

Hi! There is no massive issue. There was a problem with reading ccm_k0 value form lua, that is already fixed internally.

Mistral, stinger, igla, mim-72 is the only affected missiles. All they have defalut value of ccm_k0 = 0.5 at the moment(in OB and release version).

good to know the bug only affects a few IR missiles and no radar missile! Do you plan to modify the default value of 0.5 for some of those missiles? The Mistral in particular has a reputation for having good counter-countermeasure, but currently it almost always go for the flares.

[Mad_Shell]

@Маэстро 

Hi! I allow myself to tag you again on this thread, because I just ran a few tests with the Igla MANPADS. I modified the ccm_k0 in the C:\Program Files\Eagle Dynamics\DCS World OpenBeta\CoreMods\tech\TechWeaponPack\Database\Weapons\manpads_missiles.lua file, and set its value to 0.0001 (almost absolute resistance to flares).

However when I tested it in DCS, it changed absolutely nothing. The Igla was still going for flares most of the time. I think that the ccm_k0 parameter is not being taken into account for missiles with the new IR seeker model (the ones with the "simple_IR_seeker" block in the lua). It seems they all have the default value of ccm_k0 = 1 instead.

That makes the Mistral, the Igla and the Stinger especially poor against flares. I would be grateful if you could take another look at this issue.

[Маэстро]

5 hours ago, Mad_Shell said:

@Маэстро 

Hi! I allow myself to tag you again on this thread, because I just ran a few tests with the Igla MANPADS. I modified the ccm_k0 in the C:\Program Files\Eagle Dynamics\DCS World OpenBeta\CoreMods\tech\TechWeaponPack\Database\Weapons\manpads_missiles.lua file, and set its value to 0.0001 (almost absolute resistance to flares).

However when I tested it in DCS, it changed absolutely nothing. The Igla was still going for flares most of the time. I think that the ccm_k0 parameter is not being taken into account for missiles with the new IR seeker model (the ones with the "simple_IR_seeker" block in the lua). It seems they all have the default value of ccm_k0 = 1 instead.

That makes the Mistral, the Igla and the Stinger especially poor against flares. I would be grateful if you could take another look at this issue.

Hi! Could you please attach a track? This bug definitely has been fixed, but it seems something is broken again.

[NOYB]

Testing, testing...

Sorry if this is the wrong place for this.  But would a moderator, please get in touch with me.

 

Thanks- NOYB

[Mad_Shell]

3 hours ago, Маэстро said:

Hi! Could you please attach a track? This bug definitely has been fixed, but it seems something is broken again.

Here are 2 tests I did, with ccm_k0 = 0.0001.

In the 1st test, against a flaring, afterburning and non maneuvering F-16, I have 4 hits out of 19 missiles. Over several tests, I obtain between 20% and 25% hit rate.

In the 2nd test, against a flaring, non afterburning and non maneuvering F-16, I have 1 hit out of 20 missiles. Over several tests I obtain between 0% and 10% hit rate.

With a ccm_k0 of 0.0001, which equals almost absolute resistance to flares, the hit rate should be about 100%.

I also want to point out that both the Igla and the Igla-S use the same missile in DCS, while they should have vastly different capabilities. I don't know which one you're trying to simulate, but having 2 different missiles for these units would be great.

Igla_0.0001_AB.trk Igla_0.0001_no_AB.trk

[Mad_Shell]

@Маэстро 

I redid a few tests, and I don't know what's going on with the coding behind the scenes, but for the IR missiles using the new infrared seeker model (Mistral, Igla, FIM-92C) the ccm_k0 parameters is defined two times. And in my tests, the 2 values had an effect on the flare resistance! I don't know if the code takes the mean value of the 2 values, or if it's something else, but for example defining ccm_k0 = 0.5 and ccm_k0 (the second one) = 0.5, had different results than ccm_k0 = 0.5 and ccm_k0=0.00001, which also had different results than ccm_k0 = 0.00001 and ccm_k0=0.00001.

And I don't know what's going on with the RIM 116A missile, this one has 2 different seeker sections ("seeker" and "IR-seeker"), and ccm_k0 is defined only once...

[TheFreshPrince]

You didn't mention the R73, but I recently did some tests with it. If the R73 is shot at a non-cold target outside of the no escape zone, which is flaring slightly before the shot, the first R73 is gonna miss nearly 100% of the time. The second missile has an overly good hit ratio, even if the target is flaring. But there's also a decent chance you're gonna miss 2 or 3 shots in a row when firing against a flaring target. I didn't experience this before one of the last 2.9 updates. This gives the R73 a way less than 50% hit chance against a flaring target, seems like a poor performance. 

The programming of the flare resistance seems either broken or rudimentary. I had prepared some track files, but that was before the recent update. So I think they are not usable anymore. Maybe you want to take a look into this missile as well. 

Edited November 24, 2023 by TheFreshPrince

[GGTharos]

IRL flaring before the missile is launched will typically have the pilot inhibit the launch because it is expected that the missile will go for a flare instead.  Flaring after the missile is launched is less effective since the missile has additional ways of discriminating the target.  So there's certainly 'poor performance' just not in the way you describe it - the second missile should be as vulnerable as the first if there are decoys in the FoV (or the sun) rather than having a 'good hit ratio'.   If flares before launch make you not want to shoot the missile because you'll waste it, then this is 'correct performance'.

Edited November 25, 2023 by GGTharos

[TheFreshPrince]

What the pilot does is another thing, but a missile shouldn't miss 100%. That's just unrealistic.

[GGTharos]

How much should it miss under these circumstances?   95%?  90%?  The pilot does a thing for a reason.

[TheFreshPrince]

The pilot (we) don't know anything about these missiles, so we can not make any decisions on when to fire or not. That's why the missiles should be programmed in a way to ensure that you can get a decent kill ratio when you fire the missile even with flares. First missile 100% miss and second missile 90% hit is not good programming, but that's just my opinion.

[GGTharos]

You know that you're told not to launch if there are within x degrees of the seeker's FoV, which is IRL doctrine.   The first missile always missing and second 90% hit is indeed strange and should be looked into, but everything else you said does not reflect reality.

[Pavlin_33]

IR seekers also have a rate-of-sight movement limitations. I am not sure if this is modeled in DCS.

[Mad_Shell]

2 hours ago, Pavlin_33 said:

IR seekers also have a rate-of-sight movement limitations. I am not sure if this is modeled in DCS.

It's modelled on the new seeker model. Now I don't want to sound rude, but I would like this thread to remain on the specific initial topic here, which is the effect of the ccm_k0 parameter for the new seeker model.