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PFunk

OK, Explain SF2 Stealth Values to Me...

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I know in the data.ini files of all "stealth" aircraft, there is an RCS and IR entry that I presume reduces the radar and heat signatures of the plane. I presume, the smaller the number the greater the "stealth"?

 

I.e. 0.1 means 10% of the radar cross section?

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I think you might be right! These are the entries in the F-117 data.ini

[DetectSystem]

.

.

.

BaseRCSModifier=0.0000005
HeatSignatureModifier=0.0010


...and the F-22A:

[DetectSystem]

.

.

.

BaseRCSModifier=0.0001
HeatSignature=0.001

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PFunk, the F-117 that was shot down during Operation Allied Force was downed by an SA-3's. The battery used a P-18 Spoon Rest to acquire it, and than used the SNR-125M1 Low Blow to track and guide the missile, the IADS never detected the plane. Only the first of the two missiles launched tracked. According to an account by one of the officers who was there the F-117 was first detected at 23km by the Spoon Rest and was tracked and engaged at 13km by the Low Blow. Also it is not common knowledge but a second F-117 was damaged by a SAM during Allied Force but made it back to base safely.  

 

The account of shoot down that I referenced above is posted here: http://simhq.com/forum/ubbthreads.php/topics/3594642/Re:_SAM_Simulator#Post3594642
 

Also these two threads contain some discussion on the issue.

 

Allied Force B-2A Raid on Belgrade

 

S-125M1 Neva (SA-3B Goa)

Edited by KJakker
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LOL.  I wonder what THAT does.

 

I'm working on converting the J-31 Chinese stealth fighter that's in the SFP1 section to SF2 use and I was just curious about how they worked.  It's just going to take some testing to make it a little more accurate because SF2 radar AI wasn't really built to handle 'stealth'.  I'd like for SAM's to at least give it a look.  Right now, when I fly over a target area, I'm invisible to radar and I don't think that's an entirely accurate picture of how it works.  Furthermore, the F-22 and F-35 aren't really 'stealth' as much as they are 'low-observable', meaning radars can picket them up eventually.

 

And, now that I have actually discovered how the engine populates air defenses in the game (thanks to an entirely different thread), that's going to affect how I view terrains and target areas.

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As far as I know, both the BaseRCSModifier and the HeatSignatureModifier are pretty much useless; it's not that they have optimistic values, it's that only extremely small numbers make a difference, if there's any. I remember reading somewhere on this forum that they did almost nothing, at least if it's the AI craft the one with the modifiers, and they couldn't tell if it did make a difference in the player aircraft.

 

You have to keep in mind that the most modern avionics that are coded in and work are from the 80s, introduced in the NA expansion. Anything more modern than that, and we just have to make-do with what we have. The stealth-related stuff apparently doesn't work, almost at all. Just don't worry about it, just like TVC or HMDs, there's nothing that allows for a proper simulation of it.

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Pfunk, I. Not sure what negative RCS and Heat Signature values do but I ran completely out of ordnance and ammo in a 2 v 12 interception of bombers plus escort never being fired upon by missiles. My wingman was flying around like he was Dory from Finding Nemo

Edited by TheStig

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As far as I know, both the BaseRCSModifier and the HeatSignatureModifier are pretty much useless; it's not that they have optimistic values, it's that only extremely small numbers make a difference, if there's any. I remember reading somewhere on this forum that they did almost nothing, at least if it's the AI craft the one with the modifiers, and they couldn't tell if it did make a difference in the player aircraft.

 

You have to keep in mind that the most modern avionics that are coded in and work are from the 80s, introduced in the NA expansion. Anything more modern than that, and we just have to make-do with what we have. The stealth-related stuff apparently doesn't work, almost at all. Just don't worry about it, just like TVC or HMDs, there's nothing that allows for a proper simulation of it.

Thank you. This is what I was looking for. I plan on using the modifiers on these aircraft, but I figured that this would only be semi-reasonable facsimile of "stealth" and you confirmed where my brain was going. I appreciate it.

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There's been some discussion on this over the past few years.

 

FastCargo explained it in this thread:

 

http://combatace.com/topic/58746-ecm-and-rcs/

 

 

 

RCS settings in the sim are calculated by the size of the 'hitboxes' for the particular aircraft. So it means for non-stealthy aircraft, the RCS should match roughly what the aircraft has in real life.

However, in the data.ini of the aircraft, there is a line called BaseRCSModifier under the [DetectSystem] portion of the ini. This modifier is exactly that, simply multiply the modifier by the rough RCS of an average non-stealthy aircraft of comparable size, and that will give you the average RCS value.

In other words, find a real world value of say something like an F-15, the projected value of the F-22, find the ratio (say something like .01), and plug that value into the BaseRCSModifier line.

FC 

 

 

But, as has been indicated, it helps to have ridiculously small numbers to affect detect-ability.  Some aircraft used negative numbers, which basically meant you couldn't lock them up, regardless of distance or radar power, and that is totally unrealistic.  So, a little while back, I investigated using positive numbers and took the F-22 on as an example.  I swapped the negative number for a positive number and found the following:

 

Entry can be found at:  http://combatace.com/topic/62762-sf2-series-dact-reports-and-related-a2a-discussions-game-only/page-68

 

 

On the last page, Saisran did a 1v1 against the F-22 in an F-14D and could not get the aircraft's radar to track.  I think this was discussed a few years back, but there is a BaseRCSModifier= and HeatSignature= line you can use in the aircraft's data.ini.  I decided to take a look at that before doing the same fight, and found the number for the F-22 to be a negative number.  I think this means the aircraft cannot be tracked at all.  I went ahead and deleted the negative before the number and did not otherwise change it.  Hazzah!  The radar will track!  However, as you'd expect, not until the aircraft is about 10NM away.  This is with the APG-71, for which I believe we have a search and track strength of 200.  The AWG-9, APG-63 and others will likely have an even shorter track range.  This is a bit more realistic; Low Observable doesn't mean "invisible" to radar, but it does mean the target requires much closer range to detect/track.  I'll have to experiment with it more; the radar was able to spot the F-22 a ways away, but it couldn't get a track, and the plane jumped from what appeared to be 25NM or so to just shy of 10 once the radar finally got to track range.  That might be why it was a negative number (to completely deny detection), not sure, but if you wanted to to test it out, remove the "-" in front of the .0001, and you will be able to track the F-22 at very close range with a very powerful radar.

 

EDIT:

So, after a bit more experimenting, I found that the APG-71 will "see" the F-22 at 148km/79.9NM, but will not track until 8NM, however, TWS kind of breaks this, since it will allow you to fire at a "seen" target, regardless of if the radar can truly track it or not; as such, I was actually able to shoot an AIM-54 at the F-22 from around this range.  It missed, but it tracked all the way to the -22.  STT is still useless at this point.  Will take up the -22 against some adversaries and see what happens.

 

EDIT 2:

Flying the F-22 with the positive RCS modifier; I flew against an F-15C_85 and an F-14A_IR.  The F-15 carried 4 AIM-7P and 4 AIM-9M, the F-14 carred 4 AIM-54A, 2 AIM-7F, and 2 AIM-9P.  Neither aircraft began maneuvering against me at the ranges where I as a player could spot "something" on my radar.  The F-15, I locked and shot at to provoke into action at about 30NM.  By the time the missile reached it, the F-15 still hadn't converted on me.  For the F-14, I was experiencing the same, but I waited to shoot, because I realized, I needed to see when the AI would naturally engage.  Knowing the F-14A had TWS like I had as a player, I wanted to see if it'd be able to shoot me even without radar feedback.  It did not.  At 12.5NM, the F-14A finally spotted me and went to "RHM_ATTACK" on the debug.  I put a pair of AIM-120's its way, it launched an AIM-54A my way.  As is the case with TWS, my warning was only "missile inbound!"  One of the two AMRAAMs connected, and I dumped chaff to fool the Phoenix.

 

Takeaways:
LO helps to dominate the battlefield.  I believe that you should be able to remove the "-" in the RCS modifier and the F-22 will still paint the room with you 99 times out of 100 if missiles are involved, and you'll finally be able to track the F-22 at extremely close range.  Bear in mind that TWS kind of breaks the rules a bit, but for AI, this isn't a problem based on my experimentation.

 
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The stock TW F-16A_Netz data is using this:

[DetectSystem]

...

BaseRCSModifier=0.2

...

 

 

Cant remember if there are more examples in stock aircraft.

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The stock TW F-16A_Netz data is using this:

[DetectSystem]

...

BaseRCSModifier=0.2

...

 

 

Cant remember if there are more examples in stock aircraft.

 

Dude.  I had absolutely no clue of this.  Thanks.

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