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  1. #41
    GOMER 2 Noodle's Avatar
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    Well, I havent crunched the numbers yet, but here are my observations from memory...

    The basic IR missile modeling in DCS, without accounting for countermeasures, exhibited tangible differences in effectiveness depending upon target aspect and Line of Sight Rate (LOSR). Throttle position and airspeed had no observable effect.

    When considering countermeasures, preemptive flares were totally ineffective regardless of number or pattern; the weapon system was able to detect the target, achieve target lock, and engage the target without any degradation in time or range.

    Reactive flares were effective, especially when employed at a beam aspect with high LOSR. The most effective flare program actually turned out to be one I had programmed for preemptive use, and used a lower dispense rate than other programs. Thus, I does not appear that "mo' flares are mo' better" is universally true.

    As for methodology, I setup a simple mission single client A-10 and a single threat system with Excellent AI. I started outside the known threat ring, and configured the CMSP while driving directly at the threat per the conditions I outlined in the previous post.

    The first three runs, I used no IRCM in order to establish baseline performance for a nose-aspect engagement. Using TacView, I noted and recorded all of the datapoints i mentioned before. Specifically, i noted the average range of the first shot, and used that number to determine the next part of the test.

    I multiplied the observed first-shot Rmax and multiplied that by 1.5 to determine the range at which i should begin premptive IRCM. Then I performed three runs for each of the preemptive flare programs, noting the data as I went. I observed no susceptability to premptive IRCM whatsoever in the DCS SA-13.

    Next I flew three runs for each of the reactive programs, waiting until receiving a MWS warning to begin employing IRCM. I continued IRCM until the missile warhead functioned or it was spoofed/missed. I still need to crunch the numbers for these engagements.

    I also flew tests that put the missile and launcher on the beam. For these tests, I created a second mission with a client A-10 at Rmax, flying at a 45deg aspect. Imagine placing a diamond inside the threat ring; I started at the bottom corner of the diamond at the southern-most point of the threat ring, and flew northwest to the western-most corner of the threat ring.

    Finally for shits n giggles mostly, I flew a nose-aspect engagement, defeated the first missile with a check turn and IRCM, then defeated follow-on beam shots with just IRCM. I cant really add those encounters to the findings, but its baby steps toward a comprehensive threat reaction.

    Rinse and repeat for all the altitudes and various conditions you wish to test for, changing only a single variable each time. Once that is done, determine the set of conditions for which you want to calculate probability data. For instance: a rear-hemisphere engagement using two missiles against a non-maneuvering A-10 employing IRCM program X.

    Select the data and calculate the launcher's probability of detection, and each missile's probability of guide, probability of hit/function, and probability of causing enough damage to cause the aircraft to crash within 5 minutes. Multiply all of these together to determine the threat system probability of kill.

    From there, you can refine IRCM programs, combine IRCM with defensive maneuvers to create a threat reaction against the DCS SA-13, and train pilots how to mitigate the SA-13 threat.

    Edit: I just realised that I didn't completely answer your question regarding susceptibilty to number versus pattern of IRCM. I have to run, but I'll come back and answer that fully later tonight.
    Last edited by Noodle; 22Dec14 at 17:47.

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    Eddie (22Dec14), El_Roto (22Dec14), Howie (22Dec14), JayPee (22Dec14), ZeroMass (22Dec14)

  3. #42
    Member JayPee's Avatar
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    Awaiting your further input. Thank you for the effort! I know such research may consume a lot of time with often only minor results.

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    Member JayPee's Avatar
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    Quote Originally Posted by IASGATG View Post
    Countermeasures are modeled as a dice roll vs angle to the target and seeker head type. Closer to the notch the more effective.
    This guy IASGATG (ED forums) has done quite some research into the modeling of Air-to-Air combat in DCS to adjust AA missile behaviour based on RW stats. Unfortunately, provided he's right, he has also found how utterly simplified and prescripted countermeasures are.. This is basically what RPG games use, a sword has a hit probability, a shield has a deflect probability, and a random number multiplies the probabilities to determine whether the turn will be a hit or miss, whichever number is greater.

    Again, if this guy's right then it's indeed a matter of spamming as many cartridges as possible.. sadly. I've asked him how he got to this conclusion, awaiting his reply.
    Last edited by JayPee; 13Jan15 at 09:47.

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    This might be of interest: the behaviour of missiles in regards to counter measures can be tuned since some patches ago (1.2.8?). There is a file ...\Config\Weapons\missiels_prb_coeff.lua which defines several probability factors.

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    Did you take a look inside the file, especially at the comments?
    Last edited by JayPee; 13Jan15 at 17:59.

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    Yeah, thanks to google translate. :o)
    I don't understand everything there - but that is not only because of the quality of the translation but rather because of my lack of theoretical background knowledge.

    Code:
    - Set the calculation of the probability of change air missiles at targets in relation to the trap before and LTC
    
    prbCoeff =
    {
    
    -------------------------------------------------- ---------------------------------------------
    - Coefficients of relative stability capture different types of heads pointing (the lower, more stable)
    - That is, the probability of failure of the correction factor missiles at a new target (trap) the type of head
    - Semiactive = 1 (reference)
    
    k0 = 0.2, - active
    k1 = 0.1, - AIM-120C
    
    -------------------------------------------------- ---------------------------------------------
    - Basic probability of change for the purpose of thermal missiles (up to the amendments to the IR signature and angles purpose)
    k2 = 0.05, - increase, if we want to quickly rip thermal rocket
    
    -------------------------------------------------- ---------------------------------------------
    - The parameters for calculating the probability of the radial velocity of the target (for radar GOS)
    
    - Probability under the best conditions for the rocket (a collision course, the high speed of the target)
    - That is the case, when the rocket is excellent selects traps and other slow targets
    k3 = 0.00001, - reduce to improve the sustainability of capture on the frontal courses
    
    - Probability under the worst conditions for missiles (perpendekulyarno purpose)
    - That is the case when the target is near zero radial velocity and rocket accompany difficult goal
    k4 = 0.02, - are increasing faster to disrupt missile at 3 and 9 o'clock
    
    - The radial velocity of the target (m / s), above which the probability of changing goals = k3
    k5 = 100, - reduce to increase the stability of the capture of the rocket on a collision course
    
    - The radial velocity of the target (m / s), below which the probability of changing goals = k4
    - The lower the speed, the slower the need to fly and stricter withstand 3 and 9 o'clock for a rocket to disrupt
    k6 = 30, - increases if it is very difficult to disrupt missile at 3 and 9 o'clock
    
    -------------------------------------------------- ---------------------------------------------
    - The impact angle targets on IR signature targets for heat seeker missiles
    k7 = 0.5, - reduced if necessary to strengthen the difference between rear and front (front = k7, side = 1, 2 = rear - k7)
    
    -------------------------------------------------- ---------------------------------------------
    - Screening target when two objects merge into one - a distant neighbor closes
    - Multiplied by the probability of a t-distant object (ie, the probability of passing an object divided by the to-t)
    - Reduce, if it is necessary to increase the effectiveness of the screen, but remember about k3 for radarnyz missiles, which comes
    - In effect at the time of the screen: it is possible k3 is too low
    k8 = 0.02, - for missiles with radar homing
    k9 = 0.01, - for missiles with thermal homing
    
    
    ----------------------------- Below prozapas to-you! -----------------------
    k10 = 0,
    k11 = 0,
    k12 = 0,
    k13 = 0,
    k14 = 0,
    k15 = 0,
    k16 = 0,
    k17 = 0,
    k18 = 0,
    k19 = 0
    }

  9. #47
    Member JayPee's Avatar
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    Sniped...

    Code:
        -- Set the calculation of the probability of change air missiles at targets in relation to the trap before and LTC
    
    prbCoeff = 
    {
    
    	-----------------------------------------------------------------------------------------------
        -- Coefficients of relative stability capture different types of heads pointing (the lower, more stable)
    	-- That is, the probability of failure of the correction factor missiles at a new target (trap) the type of head
    	-- Semiactive = 1 (reference)
    
    	k0 = 0.2,			-- active 
    	k1 = 0.1,			-- AIM-120C
    
    	-----------------------------------------------------------------------------------------------
    	-- Basic probability of changing goals for thermal missiles (up to amendments to the IR signature and angles purpose)
    	k2 = 0.05,			-- increase, if we want to quickly rip thermal rocket
    
    	-----------------------------------------------------------------------------------------------
    	--		parameters for calculating the probability of the radial velocity of the target (for radar GOS)
    
    	-- probability under the best conditions for the rocket (a collision course, the high speed of the target)
    	-- that is the case, when the rocket is excellent selects traps and other slow targets
    	k3 = 0.00001,		-- reduce to improve the sustainability of capture on the frontal courses
    
    	-- probability under the worst conditions for missiles (perpendekulyarno purpose)
    	-- that is, the case where the target is near zero radial velocity and rocket accompany difficult goal
    	k4 = 0.02,			-- increase faster to disrupt missile at 3 and 9 o'clock
    
    	-- the radial velocity of the target (m / s), above which the probability of changing goals = k3 
    	k5 = 100,			-- reduce to increase the stability of the capture of the rocket on a collision course
    
    	-- the radial velocity of the target (m / s), below which the probability of changing goals = k4
    	-- The lower the speed, the slower the need to fly and stricter withstand 3 and 9 o'clock for a rocket to disrupt	
    	k6 = 30,			-- increases if it is very difficult to disrupt missile at 3 and 9 o'clock 
    
    	-----------------------------------------------------------------------------------------------
    	--		impact angle targets on IR signature targets for heat seeker missiles
    	k7 = 0.5,			-- reduced if necessary to strengthen the difference between rear and front (front = k7, side = 1, 2 = rear - k7)
    
    	-----------------------------------------------------------------------------------------------
    	--		shielding target when two objects merge into one - a distant neighbor closes
    	--		multiplied by the probability of a t-distant object (ie, the probability of passing an object divided by the to-t)
    	--		reduced if necessary to increase the efficiency of the screen, but remember about k3 for radarnyz missiles, which comes
    	--		in force at the time of screen may k3 is too low
    	k8 = 0.02,			-- missile with radar homing
    	k9 = 0.01,			-- for missiles with thermal homing
    
    
    	----------------------------- below to-you prozapas! -----------------------
    	k10 = 0,
    	k11 = 0,
    	k12 = 0,
    	k13 = 0,
    	k14 = 0,
    	k15 = 0,
    	k16 = 0,
    	k17 = 0,
    	k18 = 0,
    	k19 = 0
    }
    I don't have time to take a look at it this week and I'll be away next week but if nobody else has done it I'll give it a shot the week after.
    Last edited by JayPee; 13Jan15 at 18:13.

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