4.37.3 AIM120 AQUISITION MODEL
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Very interesting read here guys regarding the AIM-120C but one thing is bothering me ever since I’ve been flying the F-15C Eagle since the latest update. I know its the same AIM-120C missile but it seems to behave differently to the F-16, I dont know whether its just my imagination but I think it tracks more accurately when you fire it from the F-15C. Has anyone done any testing to see if there’s any noticeable difference? Maybe its due to the radar? I know for a while we were blaming changes to the AIM-120 for missed shots and bogey’s dodging our AIM-120s but now I’m not so sure its the missile but something else. Sorry to go off topic a bit maybe this deserves a separate thread?
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@Kavelenko said in 4.37.3 AIM120 AQUISITION MODEL:
Very interesting read here guys regarding the AIM-120C but one thing is bothering me ever since I’ve been flying the F-15C Eagle since the latest update. I know its the same AIM-120C missile but it seems to behave differently to the F-16, I dont whether its just my imagination but I think it tracks more accurately when you fire it from the F-15C. Has anyone done any testing to see if there’s any noticeable difference?
Strictly idenditcal AIM120 model and code
Maybe its due to the radar? I know for a while we were blaming changes to the AIM-120 for missed shots and bogey’s dodging our AIM-120s
That was before 4.37.3 aquisition update
however, there are still some quirks in guidance model particularly in terminal stage.
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@Kavelenko - and I would expect that. The F-15 has a bigger, better radar…and one can’t really consider the AIM-120 without considering the radar.
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
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@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
If you can’t change the reality, try to change your expectations…
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@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Kavelenko - and I would expect that. The F-15 has a bigger, better radar…and one can’t really consider the AIM-120 without considering the radar.
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
It’s good that you consider things but the reality is that a long as FCR lock is maintain , the relative performance (read SNR of concract) has nearly no impact ( 10% difference max in some extreme conditions on the UV)
At the moment the errors build in for every radars are identical so no difference here either
Overall we shouldn’t see any difference really if FCR lock is maintained
It is true that lock is easier to maintain with f15 than f16 due to more powerful radar
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@Mav-jp said in 4.37.3 AIM120 AQUISITION MODEL:
@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Kavelenko - and I would expect that. The F-15 has a bigger, better radar…and one can’t really consider the AIM-120 without considering the radar.
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
It’s good that you consider things but the reality is that a long as FCR lock is maintain , the relative performance (read SNR of concract) has no impact at all .
It is true that lock is easier to maintain with f15 than f16 due to more powerful radar
100% agree. This way of thinking that if larger = better in every aspect is simply false.
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@TOPOLO said in 4.37.3 AIM120 AQUISITION MODEL:
@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
If you can’t change the reality, try to change your expectations…
Exactly. I’m trying to fit the disparate performance I’m reading about here into the reality of the actual aircraft…after talking to a few RL fighter/Viper drivers I know, I’m finding some of my observations are actually correct.
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@Mav-jp said in 4.37.3 AIM120 AQUISITION MODEL:
@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Kavelenko - and I would expect that. The F-15 has a bigger, better radar…and one can’t really consider the AIM-120 without considering the radar.
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
It’s good that you consider things but the reality is that a long as FCR lock is maintain , the relative performance (read SNR of concract) has nearly no impact ( 10% difference max in some extreme conditions on the UV)
At the moment the errors build in for every radars are identical so no difference here either
Overall we shouldn’t see any difference really if FCR lock is maintained
It is true that lock is easier to maintain with f15 than f16 due to more powerful radar
Not entirely…it’s FAR more complex than that - and in some cases I may not even need a radar track at all… But all that’s not a topic for discussion here.
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@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Mav-jp said in 4.37.3 AIM120 AQUISITION MODEL:
@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Kavelenko - and I would expect that. The F-15 has a bigger, better radar…and one can’t really consider the AIM-120 without considering the radar.
…and I too am left to consider that it’s the radar model that is making the new missile model behave worse than I expect…I still say the 4.35 model met my expectations for the missile far better.
It’s good that you consider things but the reality is that a long as FCR lock is maintain , the relative performance (read SNR of concract) has nearly no impact ( 10% difference max in some extreme conditions on the UV)
At the moment the errors build in for every radars are identical so no difference here either
Overall we shouldn’t see any difference really if FCR lock is maintained
It is true that lock is easier to maintain with f15 than f16 due to more powerful radar
Not entirely…it’s FAR more complex than that - and in some cases I may not even need a radar track at all… But all that’s not a topic for discussion here.
You know but you can t tell
Great , good for you , but it’s not useful at all for us.
Enjoy what you have
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@Mav-jp - I’m still looking at ways to put the 4.35 model into 4.37. I know I’ll break things - MP mostly - but I’m not really sure I’m going to care at this point. I’ll be the only one using it…as long as it behaves in accord with my expectations/experience.
If I can actually make this play I may also start looking at a few other things I know about, just to see what can be done with what I learn. But I’m not in any rush.
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@Stevie said in 4.37.3 AIM120 AQUISITION MODEL:
@Mav-jp - I’m still looking at ways to put the 4.35 model into 4.37. I know I’ll break things - MP mostly - but I’m not really sure I’m going to care at this point. I’ll be the only one using it…as long as it behaves in accord with my expectations/experience.
If I can actually make this play I may also start looking at a few other things I know about, just to see what can be done with what I learn. But I’m not in any rush.
yep, there is a way, reinstall 4.35
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@Mav-jp music to my ears
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@Mav-jp - I’ve kept multiple installs around for years…I may torch 4.36, though. But I’ll want the legacy ones around to compare to what I fiddle with.
…4.35 may become my personal end-point.
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I don’t get the point of this… it’s not like AMRAAMs are totally broken and worthless.
Going back and staying at 4.35 is a ridiculous idea. There are literally hundreds (maybe in the thousands) of fixes between that version and where we are now. And it’s about to get even larger.
PS, you can’t possibly tweak anything in 4.37 to make the AMRAAM like it was in 4.35…that’s all internal code… at most you could do is mess up the flight model and seeker parameters.
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Looks like radar (quality of data) has a much larger effect on engagement performance than missile. I have heard that TWS is of a low enough quality to that it is a rule not to use it (outside of needing 3+ or 5+ simultaneous engagement beyond TTS or MTS abilities of course).
I wish I could find the reference but I swear I’ve heard that there is an interpolation of DL updates and seeker info throughout the engagement process. Even when the missile “sees the target” he should still take efforts to blend DL data. Obviously the blend will start DL-heavy and end DL-lite but every DL update is weighed (Kalman filter?). RCS size setting would likely play a role into that blend balance.
Remind me if BMS has RAID. AIM-120 should be able to assign EONs to different missiles to sub-target a cluster which returns as a single track. I know that’s well beyond the already challenging task of a 1 missile, 1 target modeling but it is an interesting notion.
I’m a bit surprised there’s no mention of weighing targets by factors other than geometric location (PRF closure aside). Weighting a contact higher that more closely matches the closure of the DL despite being slightly farther away from the geometrical position seems sensible.
Hopefully for testing purposes there can be a debugging way to specify repeatable “random factors” to at least have a solid representative sample instead of just having to play on the final product and do the statistical analysis, at least before the final draft.
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Can we please level up the discussion and not have “I heard”, “I know”, …?
Doing this research was heavy enough and I’d like the posts here to be documented and a bit more serious.
Facts vs facts…
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@mirv - then I’ll stay at 4.35. As mentioned, the 4.35 model behaves far more like I expect an AIM-120 to behave based on differences between RL experience and what I’ve read here. That’s why “I don’t care how it works, I care how it behaves”. BUT…
I have to now question the F-16 as a platform and how that may or may not factor. After all, the Viper is an old platform - 50 years old…I was first introduced to the 120 in the mid 80s, and I know it’s only improved since then.
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Questioning the Viper as a platform is a weak argument, and not really relevant here since this is a PC simulator. Sure there’s going to be physical limitations with the radar’s size, power, and other attributes, but the Viper’s radar isn’t the same as when the A model was introduced. The radar’s hardware and software have improved over the years with the various blocks and MMC upgrades have improved capability and supported the latest and greatest AMRAAM variants. Now the F-16s are getting SABR…so does that mean they should be questioned as a shooting platform? Hardly, but then again, we were talking about real world vs PC simulator.
What would actually be helpful, is recording ACMIs of what the missiles are doing in 4.35 vs 4.37 and explain what you believe the problem is and maybe what should be done instead. Just saying the 4.35 model is better doesn’t explain anything. The missiles in 4.35 IIRC can do some crazy stuff…
Staying two versions back in a sim just because of how ONE missile performs is also weak–but that’s your decision. You’ll miss out on everything else that’s been worked on. Obviously Mav-jp has spent many, many hours working on the AIM120 acquisition model, found bugs and have fixed them… I doubt he’s 100% done…if you’ve been around him for the last 10+ years like many of us have, he usually circle’s back and finds mistakes he’s made and he fixes them… sometimes on his own, sometimes with the help of others…but he’s determined to do things as “right” as he can and within his reach…
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I think the discussion drifted away from acquisition to the general changes of the missile performance.
I remember the ranges that we were used to in 4.35. The tactics in BVR were a complete different story compared to now.
Today we (especially my squadron) complain about guidance behavior of the AIM-120C and we learned that this part seems to be mostly untouched since the old Microprose days.
So instead of wining and complaining because we can not apply the tactics of 4.35 any more we should wine and complain about the old guidance code, that’s still in place!
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@Razor161 said in 4.37.3 AIM120 AQUISITION MODEL:
I think the discussion drifted away from acquisition to the general changes of the missile performance.
I remember the ranges that we were used to in 4.35. The tactics in BVR were a complete different story compared to now.
Today we (especially my squadron) complain about guidance behavior of the AIM-120C and we learned that this part seems to be mostly untouched since the old Microprose days.
So instead of wining and complaining because we can not apply the tactics of 4.35 any more we should wine and complain about the old guidance code, that’s still in place!
Next update will include some small changes in guidance code that will likely improve the weird behavior observed sometimes