Weapon endgame. Makes no sense to me. Please help.

[wyskass]

Can someone explain weapon endgame calculations?
In recent combat, I was not able to get a single hit, between my PL-15 and F16 defender. While I got shot down about 75% of the time.
The problem is that the math in the log makes no sense, and I have no idea while there is such a discrepancy.

Some examples:
02:15:22 - Weapon: PL-15 #7664 is attacking F-16CM Blk 50 Falcon with a base PH of 90%. PH adjusted for distance: 43%. F-16CM Blk 50 Falcon has nominal agility: 4.9, adjusted for altitude: 4.9. Agility adjusted for proficiency (Veteran): 4.9. Aircraft has a weight fraction of 0.11 - Agility adjusted to 4.57. High-deflection impact (no effect on agility). Final agility modifier: -46%. Final PH: 1%. Result: 78 - MISS

02:17:25 - Weapon: PL-15 #7668 is attacking F-16CM Blk 50 Falcon with a base PH of 90%. PH adjusted for distance: 49%. F-16CM Blk 50 Falcon has nominal agility: 4.9, adjusted for altitude: 4.7. Agility adjusted for proficiency (Veteran): 4.7. Aircraft has a weight fraction of 0.13 - Agility adjusted to 4.34. High-deflection impact (no effect on agility). Final agility modifier: -43%. Final PH: 6%. Result: 68 - MISS

Contrast with the F16 hitting me 75% of the time.
02:24:44 - Weapon: AIM-120D AMRAAM P3I.4 #7690 is attacking 95th Red #13 (J-11B Flanker B [Su-27SK Copy]) with a base PH of 95%. 95th Red #13 has nominal agility: 4.5, adjusted for altitude: 4.5. Agility adjusted for proficiency (Regular): 3.6. Aircraft has a weight fraction of 0.36 - Agility adjusted to 2.83. Agility adjusted for rear-oblique impact effect: 2.4. Final agility modifier: -24%. Final PH: 71%. Result: 60 - HIT

02:24:43 - Weapon: AIM-120D AMRAAM P3I.4 #7692 is attacking 95th Red #16 (J-11B Flanker B [Su-27SK Copy]) with a base PH of 95%. 95th Red #16 has nominal agility: 4.5, adjusted for altitude: 4.5. Agility adjusted for proficiency (Regular): 3.6. Aircraft has a weight fraction of 0.34 - Agility adjusted to 2.86. High-deflection impact (no effect on agility). Final agility modifier: -29%. Final PH: 66%. Result: 59 - HIT


I am flying a Flanker B. I understand the distance reduction, and then what seems like a reduction of the F16 from nominal. Then when it says -46% agility, it sounds like the F16 reduction. Then Wham, 1%.. Based on what?

What am I missing here? And how am I to judge my chances for a hit in a particular situation?

[cristianwj]

I guess your PL-15's launched at maximum distance? so the PH possibility was halved by the distance adjust.
F-16 is a plane have good maneuver abilities, so the final PH droped again, makes impossible to hit the F-16.

I think check the ROE and WRA settings of specific weapon could help you make success. But the mechanism of weapon hit calculation didn't revealed.

[boogabooga]

I think you should post a save in Tech support. It looks like the AIM-120D does not have the PH adjusted for distance for some reason.

[Gunner98]

02:15:22 - Weapon: PL-15 #7664 is attacking F-16CM Blk 50 Falcon with a base PH of 90%. PH adjusted for distance: 43%. F-16CM Blk 50 Falcon has nominal agility: 4.9, adjusted for altitude: 4.9. Agility adjusted for proficiency (Veteran): 4.9. Aircraft has a weight fraction of 0.11 - Agility adjusted to 4.57. High-deflection impact (no effect on agility). Final agility modifier: -46%. Final PH: 1%. Result: 78 - MISS

Breaking it down a little more:

-base PH of 90% - This is about the weapon. From the DB for the specific weapon you are using
-PH adjusted for distance: 43%. - This is because you are firing from long range. Adjust your WRA range down for 4th & 5th gen fighters and your pilots will hold onto their missiles until the range closes and decrease this adjustment. This might be affected by mid or late course guidance adjustments or supporting radars. Not sure
-F-16CM Blk 50 Falcon has nominal agility: 4.9, adjusted for altitude: 4.9. Agility adjusted for proficiency (Veteran): 4.9. Aircraft has a weight fraction of 0.11 - Agility adjusted to 4.57.
---This one is all about the target and is pulled from the AC DB. I am not 100% sure how the correlation works but I think it is ~1% adjustment for each 10th of a maneuverability point. High maneuverability AC doing that Top Gun stuff are hard to hit
---Maneuverability of 4.9 (out of 5 I think). Carrying a bit of weight which adjusts it down to 4.57 (46%), and at high enough altitude that the target doesn't need to worry about driving into the ground
---The quantify pilot quality so this guy is Veteran, so no real impact. An Ace would make it harder, a Cadet pretty easy
-High deflection impact - not sure exactly but probably means that the angle between the missile and target were high enough that the missile has a good chance to lock on, vice a front or rear shot providing a smaller target.
-Nothing in here about jamming or decoys so they must not be present

So with a base hit chance of 43% (weapon and range)
And a base defence value of 46% (maneuverability only in this case)
You essentially have 0% chance of hitting the target, but the game gives you a default of 1% - those 1% shots really start to add up when flying through AAA but beyond that it is effectively a wasted shot, unless you're trying to force the defender into a bad situation or something.

Conversely the Aim-120 is considered a better weapon (95 vice 90%). There is no range factor applied so shorter distance or more mitigation. The Su-27 is less maneuverable (4.5 vice 4.9) , the pilot is only regular which drops the maneuverability to 3.6. The Flanker is also heavier (carrying more weapons and/or fuel) which drops the agility down by a third to 2.86 (29%)

Base hit chance = 95%
Base defence value = 29%
Chance to hit = 66%
rolled under that - 59 and gets a hit

The factor differences are all fairly small but they add up to make a big impact. Pilot proficiency and weight of the target made the flanker easy to hit, distance of shot and high agility made the Falcon hard to hit

Hope that helps

B

[boogabooga]

I think that it is strange that the AIM-120D does not have the range factor applied. That is really the OP's issue here; one side has a 40% hit probability reduction that the other does not.

I just did a test and at about the same range, the AIM-120D does not have the range factor applied but PL-15 does.

Also, did anyone else notice that missiles in CMO seem to follow a pure-pursuit terminal guidance routine? I would expect many would actually follow a proportional guidance or similar target-leading technique. I wonder if that is abstracted into the "High-deflection impact" modifier somehow?

[Dimitris]

Also, did anyone else notice that missiles in CMO seem to follow a pure-pursuit terminal guidance routine? I would expect many would actually follow a proportional guidance or similar target-leading technique. I wonder if that is abstracted into the "High-deflection impact" modifier somehow?

It's a combination of pure-pursuit and intercept heading, depending on the current angle-on-bow. Always relying on intercept guidance can result in very wierd "ETA near eternity" situations under certain circumstances. Same with torpedo guidance.

[KungPao]

I think you should post a save in Tech support. It looks like the AIM-120D does not have the PH adjusted for distance for some reason.

Yes, a save file would be helpful but from the log it looks like the F-16 fire the AIM-120D at close range so it doesn't suffer long distance penalty


02:17:25 - Weapon: PL-15 #7668 is attacking F-16CM Blk 50 Falcon

02:24:44 - Weapon: AIM-120D AMRAAM P3I.4 #7690 is attacking 95th Red #13

Here is my guess, J-11B released PL-15 at max range then follow missile straight in (and probably the doctrine setting set at use BVR and WVR weapon) . F-16 evade the PL-15, the distance between these two close to 40nm, now it is F-16's turn to fire AIM-120D...

[boogabooga]

No, I did my own test. Even at nearly the same range, the 120D is not subjected to the same penalty.

[KungPao]

Back in CMANO days, this is how the final PoH calculated. I think the CMO is using the same formula

Final PH = Weapon Base PH- distance adjustment – [A/C Agility at current Altitude x Proficiency coefficient<1> x Weight adjustment coefficient x (1-damage%) x impact location coefficient] – Sea skimmer modifier


<1>. Ace = ? , Veteran = 1, Regular = 0.8, Cadet = 0.5

[KungPao]

No, I did my own test. Even at nearly the same range, the 120D is not subjected to the same penalty.

Ahhh, Ok thank you . Guess we need to report this to Tech Support.

[boogabooga]

It's a combination of pure-pursuit and intercept heading, depending on the current angle-on-bow. Always relying on intercept guidance can result in very wierd "ETA near eternity" situations under certain circumstances. Same with torpedo guidance.

Sure, but then the missile end game will more often end up with a stern chase geometry rather than coming from the beam, and one can't really count on the final in-game geometry being "realistic." What is the "High-deflection impact" variable abstracting? There might be an issue if the weapon endgame calculation is using the actual simulated geometry to calculate the chance of hit, but that geometry is actually just coming from another abstraction. If that makes sense?

[wyskass]

Thanks for the explanations.

So it comes down to the AIM-120 in these cases incorrectly not applying any distance factor. I missed the absence of the distance modified from the F16, and didn't expect a bug. Will post it that section.

Also, now I can see the percentages are subtractive not multiplicative, and realize that the carried fuel fraction can make a difference. I was chasing these F16's down after they seemed to have turned back RTB

I was firing at about 80 of the 94 nm range, and he was also staying back when firing, so not significantly closer.
In fact the AIM max range is 87 to my 94. In some cases, marking his fire point, I'd turn off Auto Evade and just outrun the missile with it petering out just a few miles behind me.
I use the DB all the time to find details, and the contrast in chances between these two was way too much for the situation.

I'm posting the save anyway.
The engagement is over Yellow Sea, with my two Flankers (A-XX-AIR 11B 3) and the 2 F16 92nm away. Results were similar in the other engagements further south. I wasn't really needing a kill on these, but wanting to push them back and distract, to maximize chances for my missile salvo to reach target.

CMO-Save_Salvo-AtoA.zip

(1.6 MiB) Downloaded 11 times

BTW, this scenario is also broken with the satellite strikes, as the satellite orbit speeds are higher than the max target speed of the ASAT missiles. It uses DB v480


Oh, and I was also wondering on the distance factor min, max or linearity. Does it go from Nominal PH at minimum range to 0% at max range? Is that an appropriate model for AA weapons? I wouldn't think it would be a linear decrease.
In the first example, with the nominal PH at 90% the distance adjustment dropped it to 43%.. so a factor of 48% for a distance 80nm/94nm of 85% or so.
Reversing it, the miss chance is 57% at 85% range. So there is some minimum chance at max range. I wonder what that is, and at what distance do you achieve no distance decrease. And is it linear or not?

[AndrewJ]

The 'high deflection impact' affects how much of the target's agility modifier gets applied.

If the weapon is coming in from the side (i.e., the plane is beaming the missile) the plane gets to apply its full agility modifier, but if If the weapon is coming in head on, or in a stern chase, then the plane will only apply part of its agility modifier.

For example:

• High deflection: 3.0
• Rear Oblique: 2.5
• Head On: 1.8
• Stern Chase: 1.5