Stealth in BMS
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@tiag said in Stealth in BMS:
@drtbkj
I dont think you would NOT implement any stealth depending on the poll. Confess, that was a simply propaganda to your modThe RCS is a nominal CS for a F-16 being detected at a given detection radar range. All values are normalized to a base case: F-16C. You will understand better when you open that excell I did with someone from the past in 2008 for AF…see please the first TAB. Some of it still applies to BMS.
LINK
(donwload it, since some formulas may not work in Google).Beware that the numerical values are for AF based on the SP3 leaked code. You need to plugin the BMS values.
And have fun…that is the most important thing!
Hi, Tiag, Thanks for the Link, and your patience for our shameless self-promotion
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@drtbkj A bit confused, as you say the stock RCS for F-35A is 0.169, are you suggesting to increase it to 0.5 (from your TE testing) or was it just a typo and you meant to say “decrease it to 0.05”, as you mention later on?
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@unkindled said in Stealth in BMS:
@drtbkj A bit confused, as you say the stock RCS for F-35A is 0.169, are you suggesting to increase it to 0.5 (from your TE testing) or was it just a typo and you meant to say “decrease it to 0.05”, as you mention later on?
He wrote F35C.
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@LorikEolmin You are completely right. Don’t know how I missed that.
Thank you, Lorik! -
I voted yes. I see BMS as remaining an F-16 simulator for the forseeable future, but if real life vipers may soon have to contend with stealthy adversaries, then we should have the choice to make theatres that represent this. No-one has to fly any particular theatre after all.
The way I see it is as a question of pure technical feasibility and how well-modelled ‘stealth’ will be.
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@drtbkj said in Stealth in BMS:
Here are some numbers for you:
RL Frontal RCS (square meters)/Values in BMS( if frontal and units unknown)
F-18C= 1-3/1.23
-F-18E=1 /1.059
F-16-1.2 / 1
F-35A= .0015(I’ve also see .005 ) / 0.169
F-22= .00015 / 0.21
J-20= 1-3 / 0.41
One important caveat to our discussion is that the BMS Editor’s unit of measure (square meters, square feet, etc.) is not given, nor if this is frontal RCS. A clarification of these would be much appreciated,
…
Comments are welcome.
I just briefly overlooked discussion…did not see answer (perhaps is hidden somewhere)
So just in short - IIRC, Falcon 4.0 RCS was the same on whole sphere (average), but it was changed later…?Unit for measure is Viper, so “F-16 is 1”, others are more or less…double F16 RCS is 2, smaller RCS planes 0.X…
Its not regular unit, its “to F-16 comparison”. (not sure about latest BMS code, this was Falcon 4 general rule imo)Sorry if someone answered already.
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@Lukas hello, yes and no… Maybe BMS mathematical law is not linear… maybe it follows a non-linear slope.
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@javelin10 said: I see BMS as remaining an F-16 simulator for the forseeable future.
Almost…
Falcon IS an F-16 simulator; Ispo facto it is named “Falcon”.
Ergo - the adjective “foreseeable” is not required.
pr0n
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@drtbkj said in Stealth in BMS:
Good Day, All.
If you’ve been following the the OFM Journal thread, you’ve seen that we are flight testing the F-35C, for flight model refinement. While we’ve been doing so, we have also experimented with Stealth.
https://militaryembedded.com/radar-ew/signal-processing/radar-cross-section-the-measure-of-stealth#:~:text=The 5G F-35 has,size of a golf ball.Here are some numbers for you:
RL Frontal RCS (square meters)/Values in BMS( if frontal and units unknown)
F-18C= 1-3/1.23
-F-18E=1 /1.059
F-16-1.2 / 1
F-35A= .0015(I’ve also see .005 ) / 0.169
F-22= .00015 / 0.21
J-20= 1-3 / 0.41
One important caveat to our discussion is that the BMS Editor’s unit of measure (square meters, square feet, etc.) is not given, nor if this is frontal RCS. A clarification of these would be much appreciated,
The point of all this that in our testing shows true Stealth has a significant effect on BMS play. When we flight tested the MQ-25 tanker we tried a RCS of .005 and you could not lock it up on radar! I’ve created a “Flight Test” TE . In it the J-20 keeps it’s 0.4 but our test F-35C has 0.5 Where before the J-20 is shooting from beyond AIM-120 range , now you can get close enough to get to shoot(even close enough to get burn through when they jam)
It may not be an exaggeration to call it a “game changer”. And that, my friends, is the point of this post. Some might say Stealth " takes the game out of the game" . What do you think? Do you want us to include Stealth in OFMKTO and perhaps the other theaters we help with? Or, leave it to you to adjust(which BTW is very easy to do)
Comments are welcome.
JoeThere is no Unit in bMS
1 is just reference for f16 and al’ the rest scales to it
So basically you need to scale all of them from real f16 RCS value
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@Mav-jp Thank you for the useful insight Mav!
Now we only have to decide what’s considered the real RCS value of the F-16.
Some sources claim that the exported F-16 has a frontal RCS of 4 to 5 m^2, while others claim some USAF squadrons that have been painted with Have Glass V have a frontal RCS of 1.2m^2.
https://nationalinterest.org/blog/buzz/did-f-16-just-go-stealth-107806
https://www.key.aero/article/have-glass-making-f-16-less-observableWhich kinda further complicates things as the sources Joe gave claim that the F18 has an RCS value of 1m^2.
All in all, an interesting discussion.
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@Mav-jp said in Stealth in BMS:
@drtbkj said in Stealth in BMS:
Good Day, All.
If you’ve been following the the OFM Journal thread, you’ve seen that we are flight testing the F-35C, for flight model refinement. While we’ve been doing so, we have also experimented with Stealth.
https://militaryembedded.com/radar-ew/signal-processing/radar-cross-section-the-measure-of-stealth#:~:text=The 5G F-35 has,size of a golf ball.Here are some numbers for you:
RL Frontal RCS (square meters)/Values in BMS( if frontal and units unknown)
F-18C= 1-3/1.23
-F-18E=1 /1.059
F-16-1.2 / 1
F-35A= .0015(I’ve also see .005 ) / 0.169
F-22= .00015 / 0.21
J-20= 1-3 / 0.41
One important caveat to our discussion is that the BMS Editor’s unit of measure (square meters, square feet, etc.) is not given, nor if this is frontal RCS. A clarification of these would be much appreciated,
The point of all this that in our testing shows true Stealth has a significant effect on BMS play. When we flight tested the MQ-25 tanker we tried a RCS of .005 and you could not lock it up on radar! I’ve created a “Flight Test” TE . In it the J-20 keeps it’s 0.4 but our test F-35C has 0.5 Where before the J-20 is shooting from beyond AIM-120 range , now you can get close enough to get to shoot(even close enough to get burn through when they jam)
It may not be an exaggeration to call it a “game changer”. And that, my friends, is the point of this post. Some might say Stealth " takes the game out of the game" . What do you think? Do you want us to include Stealth in OFMKTO and perhaps the other theaters we help with? Or, leave it to you to adjust(which BTW is very easy to do)
Comments are welcome.
JoeThere is no Unit in bMS
1 is just reference for f16 and al’ the rest scales to it
So basically you need to scale all of them from real f16 RCS value
Thanks, Mav, for that confirmation.
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@unkindled said in Stealth in BMS:
@Mav-jp Thank you for the useful insight Mav!
Now we only have to decide what’s considered the real RCS value of the F-16.
Some sources claim that the exported F-16 has a frontal RCS of 4 to 5 m^2, while others claim some USAF squadrons that have been painted with Have Glass V have a frontal RCS of 1.2m^2.
https://nationalinterest.org/blog/buzz/did-f-16-just-go-stealth-107806
https://www.key.aero/article/have-glass-making-f-16-less-observableWhich kinda further complicates things as the sources Joe gave claim that the F18 has an RCS value of 1m^2.
All in all, an interesting discussion.
Hi, Unkindled. Thanks to Mav’s response, we now know what we need to do( Ie: compare to the Viper). You see, the BMS F-18C value is 1.23… if, memory serves. That seems like a good value. The F-18E will be lower
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@drtbkj I may be missing something, but if we take the reported RCS of the F-18 mentioned in the two sources you have provided as truth, then the F-18 has a lower value. Not sure by how much relatively speaking.
If we assume that modern (as in now currently used) F-16C have an RCS of 1.2m^2, shouldn’t we divide the F-18’s RCS value by it to scale it to real world data (assuming a linear function in BMS). Therefore wouldn’t a higher value for the F-18 be “wrong”? E.g. In BMS F-16 RCS is 1, actual RCS is 1.2, F-18 RL is 1, so F-18 in BMS should have a value of 0.8333.
Please correct me if I’m wrong, haven’t managed to read the other source concerning RCS from the NPS.
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You guys will pork completely Falcon.
You cant simply normalize the RCS of new acft based on the F-16. It does not work this way. The “RCS” in DB is a normalization factor in the radar range equation in Falcon. Did you check the excell table I put the link?
Moreover, the radar range equation DOES NOT scale linear with the radar cross section. -
@Mav-jp
Unless you have rewritten completely, this is not correct.
I dont think you have rewritten since the “RCS” are still similar to the old ones, i.e. I dont see the changes that would indicate that the code takes into account the real RCS in the calculation.The “RCS” in the Database is a multiplication factor for the nominal radar range:
Radar Detecion Range= Nominal Range (from DB) x “RCS” (from DB)If you plug the real RCS, it will simply not work, because the real RCS goes with ^1/4 in the max radar range formula.
EDIT: BY consequence, all max radar ranges in the DB are the nominal radar ranges where acft like the F-16C is detected…“RCS” is 1 (=normalized).
@drtbkj
Here is an example using the CMO DB as baseline (“true”) to calculate such “RCS” factor in BMS (all frontal values for E-M bands):
#1 Shows that BMS “RCS” factor matches the calculated ones using CMO, taking into account the corresponding power law.
#2 Shows that this matching gets even better if one takes into account an average RCS from CMO. Compare yellow marked cells for the case of F-15C -
@javelin10 said in Stealth in BMS:
I voted yes. I see BMS as remaining an F-16 simulator for the forseeable future, but if real life vipers may soon have to contend with stealthy adversaries, then we should have the choice to make theatres that represent this. No-one has to fly any particular theatre after all.
The way I see it is as a question of pure technical feasibility and how well-modelled ‘stealth’ will be.
Real life F-16 may soon have to deal with this threat, but real life F-16’s also still get updated with new toys (AESA radar etc.). So if you want to realistically model dealing with this new threat, then the BMS F-16 also needs to be updated. And most of the information on these new toys are still classified, so this will be difficult to do in a realistic way I’m afraid.
Interesting article on the F-16’s future:
https://www.thedrive.com/the-war-zone/air-force-holding-off-developing-new-f-16-replacement-for-now"608 F-16s from Blocks 40/42 and 50/52 — the service’s youngest F-16s — will receive a total of 22 modifications under the program. Planned updates include the addition of a Center Display Unit, a Programmable Data Generator, and “several other key hardware components to modernize the aircraft.” In addition, the F-16 will receive the AN/APG-83 Active Electronically Scanned Array radar (AESA), new electronic warfare capabilities, advanced mission computer, and a communications suite upgrade that includes an updated Link-16 datalink capability. The USAF says this new communication system will convert the fleet to “a high-speed data network.”
"Mark Rossi, Northrop Grumman’s director of SABR programs, told The War Zone that the addition of the SABR was the closest thing an F-16 could get to F-35 performance within the limitations of the jet. "
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@tiag said in Stealth in BMS:
@Mav-jp
Unless you have rewritten completely, this is not correct.
I dont think you have rewritten since the “RCS” are still similar to the old ones, i.e. I dont see the changes that would indicate that the code takes into account the real RCS in the calculation.The “RCS” in the Database is a multiplication factor for the nominal radar range:
Radar Detecion Range= Nominal Range (from DB) x “RCS” (from DB)If you plug the real RCS, it will simply not work, because the real RCS goes with ^1/4 in the max radar range formula.
EDIT: BY consequence, all max radar ranges in the DB are the nominal radar ranges where acft like the F-16C is detected…“RCS” is 1 (=normalized).
@drtbkj
Here is an example using the CMO DB as baseline (“true”) to calculate such “RCS” factor in BMS (all frontal values for E-M bands):
#1 Shows that BMS “RCS” factor matches the calculated ones using CMO, taking into account the corresponding power law.
#2 Shows that this matching gets even better if one takes into account an average RCS from CMO. Compare yellow marked cells for the case of F-15CYou misread me completely , I never said we need to plug real values
I said RCS real values need to be scaled on the f16 real value vs 1
If (4) power factor need to be taken into account need to be checked with current code
however I’m not sure the current DB values have been done with a power factor. This data is there since 2002/2004 , did you check if current DB more or less match Scaled RCS with (1/4) power factor ?
Also indeed average RCS values vs incidence must be taken into account and not only the lowest
I had the intention to code RCS vs incidence but I forgot and now it’s over .
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@Mav-jp Sorry, I understood well what you wrote but I thought that @drtbkj and @unkindled got it wrong, by reading their messages. My message was more to them.
“Did you check if current DB more or less match Scaled RCS with (1/4) power factor ?”
Yes, it matches. I wrote a quick script to extract the RCS from CMO DB, then calculated an average frontal/side RCS, then scaled to F-16C RCS, then used the power law, then compared to BMS.
This data is graphed below: X-Axis is “RCS” factor from the BMS 4.36 DB, Y-Axis is the calculated (as decribed in the previous line) from CMO DB.
Both data more or less match.
So, if someone wants to edit correctly the “RCS” factor in BMS, it needs to take into account the power law. Or you change the code and the whole RCS in the DB needs to be re-done.
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Go for realistic RCS values in BMS!!!