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Weapons & Countermeasures Modeling in Falcon 4.0:
Interview with Realism Patch Group's "Hoola"
by Paul Stewart[Paul] Let's talk about ARH and SARH missiles. What factors did you incorporate when modeling the seeker properties of these missiles?
[Hoola] For SARH missiles, it is the host radar of the launching platform that is important. For this, I incorporated basic radar principles, and then modeled the radar based on the research material. Included in the models were factors such as the type of tracking mechanism (pulse or pulse Doppler), beamwidth, antenna field of regard, etc., as well as the sophistication of the radar processor. All these have an impact on the ability to track look down targets, etc, and the ability to recognise chaff.
You can say that the SARH missile modeling is basically about modeling the individual aircraft radars. Some radar performance data are available from public sources such as those published by Jane's Information Group, and then one can use the radar equations to solve for factors like detection range for various RCS, and determine how these numbers should go into the game. One must have some experience in the field to do this, however, as there are many sources of misleading and disinformation on the internet.
For ARH missiles, modeling took into account the properties of monopulse seekers. Sources for this information included the Journal of Electronic Defense, which were used and referenced.
[Paul] You keep saying that you obtained this from "public information". Why is it important to emphasize this?
[Hoola] It is important to stress that all these information are not privileged, not just to stay out of trouble, but also, there are lives that depends on the protection of privileged information.
[Paul] So ultimately if anyone was to come out and say "I have truly modeled this on the ACTUAL performance"..they should probably be in jail!
[Hoola] Yes. I have been offered privileged information before, by individuals who are in the position to access them. Surprisingly, it was from a NATO country. However, I rejected the offer to see the information as this would not be right, and moreover, lives depend on these systems.
[Paul] I'd like to talk a bit more about the ECM war, You discuss it a lot in the User's Guide. What was modeled for the F16? Could you explain the details included in "burn through" and "angular coverage" and the like? Also, why is it that ECM performs so poorly against missiles like the AIM120 and AA12?
[Hoola] F4 models radar in terms of signal strength. What we modeled for the F-16 is no different from what we modeled for any other radar in the game. First of all, the ECM model in F4 is a simplified one, but it approximates the J/S (jamming to signal) ratio relationship, in that ECM is mechanised simply as signal degradation. This is not wrong, as jamming is all about J/S ratio, be it noise or deception jamming.
The ALQ-131 Self Protection Jammer Pod
I first modeled some radiated power for each radar (based on information available on public sources, such as Jane's Electronic Warfare and Radar). For radars that we have no information, we took its size into account, and modeled the ERP (radiated power). We then accounted for jamming power output (again, a rough order of magnitude based on what the power output will be, which again is based on physical sizing estimation, etc.), and worked out the J/S relationship as a function of distance.
"Burn through" refers to the range at which the radar transmission will over-power the jamming signal and allow the radar to lock-on onto the target (for deception, it also means the distance at which deception jammer does not have enough power to steal the radar gates). This defines the baseline radar ECM performance. It is then modified somewhat by estimating on the ECCM capabilities to allow some degree of ECCM modeling.
I think the question of 100% accuracy is moot though. Of course a full model on radar can be coded in F4, but radar equations are computationally very intensive. Unless you want JF-18 type of fps, the current F4 model is good enough. This is not to say JF-18's radar is accurate though, as I have not looked at it in detail.
On the last thing regarding ECM coverage, what I did was to define a generic 3dB beamwidth in azimuth and elevation for the jammer. This is based on observation from pictures of various jammer pods and internal systems, and from there, I estimated the coverage of each system and then took a middle of the road generic value. Of course, the coverage can be reduced and made narrower, but gameplay wise it will have a big impact, as players will need a full month long ground school just to learn how to use ECM properly, let alone enjoy the game. Right now, the coverage is somewhat generic but accurate, and yet it allows the player to experience the limitations and tactical considerations of employing such systems. The key objective is to allow players to experience what it is like having to use these systems.
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