I've been doing a lot of testing and have after about 2 days of nothing but decoy testing here's what I hope is the definitive solution for making fully working chaff and flare decoys.
In the game, the engine classes all decoys as capable versus "radar" as a valid target. This will be the case no matter what actual targets are set in the database. So the question arises as to how an IR decoy or torpedo decoy system knows how to apply a modifier during point defence resolution.
It was driving me to distraction until I decided to go back to basics and dug up the old H2 on-line help manual. That's where I found the answer as well as looking at the ingame database display and seeing how the engine interpreted my values. Here's what I found in the H2 manual and the database editor section:
Decoy
Either may be given propulsion, launch parameters, and Bearing-Only Launch capability to model deception decoys (such as ADM-141 TALD) or may be used for point-defense missile/torpedo distractors. In the latter role, the Ph/ATA values take on different meanings. Surface Near PH = PH reduction versus acoustic homing torpedoes
ATA Near = PH reduction versus radar-homing (active or semi-active) weapons
ATAFar = PH reduction versus IR homing weapons.
**** NOTE Use standard % for the surface near value and the Harpoon miniatures ATA value system for the anti missile decoys that use the ATA fields ****
I have found that it is possible to build chaff-like weapons that carry an ECM sensor and the Track Output value in the sensor is used as the modifier against an incoming radar guided weapon attack. This system unfortunately doesn't work for IR (Flare) decoys. I would suggest that's because the IR missiles are "passive" homing and there's really nothing to jam as far as the game is concerned. A stand-alone IR - ECM system will work as a Sensor, but will not fuction in the form of sensor on board a disposible flare based IR decoy (weapon).
Here's an example of how I've built a working flare and how to calculate the modifier that the decoy applies.
Name: Flare
Type: Decoy
Launch Alt Max: 20000m
ATA Atk (Far): 2
That's it a working flare, and you really don't have to do much to make one, no target selection just be aware of the ATA value in the "Far" database field and you're away. Here's an AA-Log extract from the game:
Weapon Sidewinder is resolving its attack against Aardvark
Attacking aircraft with base pK: 95%
Plane evading with a DATA of 30
++++++++
+ Starting Point Defense Calculations.
+ Defending Unit is Aardvark.
+ Target weapon is Sidewinder.
++ Resolving Weapon Fire for Point Defense.
++ Defending Weapon is Chaff (H).
++ Incoming Weapon is Sidewinder.
++ Firing Unit is Aardvark.
++ Bamf! (Missile Decoy Worked in EM Mode)
++ 1 Chaff (H) left.
+ Number Shot Down by Mount was 0
++ Resolving Weapon Fire for Point Defense.
++ Defending Weapon is Chaff (I).
++ Incoming Weapon is Sidewinder.
++ Firing Unit is Aardvark.
++ Bamf! (Missile Decoy Worked in EM Mode)
++ 7 Chaff (I) left.
+ Number Shot Down by Mount was 0
++ Resolving Weapon Fire for Point Defense.
++ Defending Weapon is Flare.
++ Incoming Weapon is Sidewinder.
++ Firing Unit is Aardvark.
++ Pop! (Missile Decoy Worked in IR Mode)
++ 11 Flare left.
+ Number Shot Down by Mount was 0
+++++++++
Total countermeasures: -20%
Final pH: 45%
Roll: 22 (Hit)
----------------------
The two Chaff decoys that launched had no effect, their ATA value is set in the ATA-Atk (near) field and that only applies as: ATA Near = PH reduction versus radar-homing (active or semi-active) weapons, no modifier is applied.
The final -20% modifier is based on the Flare's Far ATA-Atk attack value of +2.0 set in the ATA-Atk (Far) field, which is a 50% kill percentage less the following because it's a DB value in the FAR ATA-Atk field and the information taken from Harpoon2 manual.
Near ATA
This is a rating representing the ability of a weapon to hit an airborne target which is, in all likelyhood, not cooperating. It is equal to the percentage chance to hit a non-maneuvering target minus 30. This rating is used by guns at less than half range, and by allother anti-air weapon at all ranges.
Far ATA
As above, but used by guns at half range or greater. - (use minus 30 above as well) - my notation
This isn't quite correct as an "unmanned target (e.g. a drone aircraft or cruise missile)" get a +0.5 (35%) in the minis rules, and H2/3 is classing them as possesing an ATA of 0.0 (30%).
So the modifier is based on the minis ATA values (loosely)
Defending Flare ATA: +2.0 = (50%)
less 30% for incoming target
Final Modifier 20% - subtracted from attacking missile to hit% see quoted log above.
The Chaff didn't cause the modifier in the above example as its Near ATA-Atk is set at +1.5 (45%) which would produce a final modifier of 15%
Defending Chaff ATA: +1.5 = (45%)
less 30% for incoming target
Final Modifier 15% - subtracted from attacking missile to hit%.
I hope this is clearer than the muddy water it first looked like to me. I know it's long winded but I'm more than happy to clarify anything that anybody has issues with. The chaff decoys above have been set up identically to the flare and so launch regardless but have no effect. My personal opinion is that all chaff-like decoys still use an on-board sensor to do their thing, but to have effective disposible IR decoys stick to the above.
Cheers
Darren