Do individual weapons/stores add to the overall RCS in DCS

[Knock-Knock]

For example, F/A-18C, clean no pylons, will it have a lower RCS in DCS, than a F/A-18C with its stores full? And if, do the given weapon types have their own RCS? So carrying 8 Mk82's, will that have a different RCS than 8x a2a missiles?

Edit: Id imagine in real life, the pylons full of Mk82's would send the RCS trough the roof, compared to a clean plane?

[QuiGon]

It does IRL (which is especially important for stealth aircraft like the F-35), but in DCS this is not simulated AFAIK.

[Knock-Knock]

Myea, nope. Just answered my own question, by quickly testing it. At least in regards to the Hornet.

 

Head on with 3 Hornets. One fully clean, one full a2a stores, and one full of Mk 82's. They all appeared on the scope at the same time (5nm separation, and they started 100nm out, in a 35k for them, and 30k feet for me alt scenario).

[Harlikwin]

Most sensor modwling in DCS is quite primitive as far as I can tell. They may model which buttons to press and what the screen looks like at the aystems level but both RADAR/EW and FLIR are really simply modeled, the best of those probably being the RADAR.

[Knock-Knock]

Yea, but I thought, that in DCS, weapons might have each their own RCS and what ever formula based on aspect/range etc, that is then added to the given planes data.

 

Wonder how much the RCS actually increases in real life. Maybe its negligible for the none-stealth jets, hence why its not 'modelled' in DCS.

[myHelljumper]

Yea, but I thought, that in DCS, weapons might have each their own RCS and what ever formula based on aspect/range etc, that is then added to the given planes data.

 

Wonder how much the RCS actually increases in real life. Maybe its negligible for the none-stealth jets, hence why its not 'modelled' in DCS.

 

As missiles (SEAD missiles sized ones so almost any missiles) can be tracked by radars at quite a long range, I would think that they can add a significant amount of RCS to an aircraft (only a guess of course :)).

[Knock-Knock]

Yea that is the thing, apparently it sometimes takes very little, visible, to really increase the RCS from a given aspect. So some pylon, weapons etc, are bound to really bump the RCS from certain angles.

 

For example: @ the 2m15 mark

Edited January 24, 2019 by Knock-Knock

[Harlikwin]

Yea, but I thought, that in DCS, weapons might have each their own RCS and what ever formula based on aspect/range etc, that is then added to the given planes data.

 

Wonder how much the RCS actually increases in real life. Maybe its negligible for the none-stealth jets, hence why its not 'modelled' in DCS.

 

LOL, no...

 

IRL you are of course right, and RCS is dynamic thing that changes on the radar/target aspect, plus doppler shift for those radars.

 

Real time sensor modeling like that would further kill the poor overworked CPU, though it may be something that they could offload onto another core since it doesn't exactly have to be real-time. But again, I wouldn't hold my breath on realistic sensor modeling. Just like having an actual Diurnal cycle for thermals, though if I understand how its rendered they just use a "thermal" texture instead of the normal ones. Same for NV.

[Deano87]

Yea that is the thing, apparently it sometimes takes very little, visible, to really increase the RCS from a given aspect. So some pylon, weapons etc, are bound to really bump the RCS from certain angles.

 

For example: @ the 2m15 mark

 

Off topic but thanks for linking that video, fascinating stuff. What a beast of an aircraft... 210-220 knot touchdown speed, with a drag chute that’s only rated for 200 knots in the first place, utter madness + balls of steel. :huh::surprise:

[drPhibes]

Real time sensor modeling like that would further kill the poor overworked CPU, though it may be something that they could offload onto another core since it doesn't exactly have to be real-time.

 

 

Real time simulation of RCS is simply not possible with existing computer technology. Even with a fairly coarse mesh and using EM solvers like UTD or PO/RL-GO, calculating the x-band RCS for an aircraft can take hours for each instance of φ and θ (azimuth and elevation) on the workstation I occasionally use for EM simulation at work (quick specs: 16 physical cores (32 with HT), 96gigs of RAM, M2 SSD etc, running altair FEKO).

 

 

 

In DCS, RCS s defined as a single parameter for all aspect ratios and frequencies. This can easily be used with the radar range equation to give a good enough approximation of actual detection range. Basically, as far as the radar is concerned, the aircraft are spheres with a given cross sectional area in dBm² (for instance the AJS 37 is defined to be 3 dBm², or 2m² for the linear folks). These values are most likely just educated guesses based on typical values for aircraft of a similar size, or something that gives the expected results when used with the other parts of the radar simulation in DCS.

[M1Combat]

"(quick specs: 16 physical cores (32 with HT), 96gigs of RAM, M2 SSD etc,"...

 

 

LOL... so like pretty close to what many run for DCS then? :)

[drPhibes]

LOL... so like pretty close to what many run for DCS then? :)

 

 

That would be comparable to using the Large Hadron Collider for heating soup :P

[Harlikwin]

Real time simulation of RCS is simply not possible with existing computer technology. Even with a fairly coarse mesh and using EM solvers like UTD or PO/RL-GO, calculating the x-band RCS for an aircraft can take hours for each instance of φ and θ (azimuth and elevation) on the workstation I occasionally use for EM simulation at work (quick specs: 16 physical cores (32 with HT), 96gigs of RAM, M2 SSD etc, running altair FEKO).

 

 

 

In DCS, RCS s defined as a single parameter for all aspect ratios and frequencies. This can easily be used with the radar range equation to give a good enough approximation of actual detection range. Basically, as far as the radar is concerned, the aircraft are spheres with a given cross sectional area in dBm² (for instance the AJS 37 is defined to be 3 dBm², or 2m² for the linear folks). These values are most likely just educated guesses based on typical values for aircraft of a similar size, or something that gives the expected results when used with the other parts of the radar simulation in DCS.

 

So what I said :). And yeah, I think they could do something a bit more sophisticated (not real time modeling) but it would be competing for CPU resources that single threaded DCS currently can't spare. You could get a bit more fidelity by breaking down average aspects, i.e. frontal, side etc and vs different bands of radar and maybe +/- stores, do the math offline, and have some value the game engine can quickly check. It would give a bit more realism at not too much "game" computation cost. But, given the limited resouces ED has I'd much rather they work on other things first (Like VR optimization). Sensor model wise personally I'd rather see better NV and thermal modeling since you don't really "see" the radar model.

Edited January 25, 2019 by Harlikwin

[Harlikwin]

"(quick specs: 16 physical cores (32 with HT), 96gigs of RAM, M2 SSD etc,"...

 

 

LOL... so like pretty close to what many run for DCS then? :)

 

DCS world 3.0 :) minimum requirements, when they get Vulkan, then people will need ALL the CORES.

Edited January 25, 2019 by Harlikwin

[falcon_120]

Something like a more complicated RCS simulation would be absolutely great though i have serious doubts about how to implement something like this.

 

If any and as a good compromise to reality, to whatever rcs value we have for every plane I guess that ED could implement some minor tweaks to the model such as:

 

If (plane X has a full bomb loadout) RCS*=1.1

 

Fine tuning to a simple model like that could include specific RCS increment for certain weapons known for increasing the RCS if that information were available.

 

In the end a real model is not only too costly from a FPS perspective but also unachievable due to lack of data. So a truly simple model like that would be more than enough while being true to expected real life behaviour.

 

Enviado desde mi SM-G950F mediante Tapatalk

Edited January 25, 2019 by falcon_120

[Harlikwin]

I think for me, the whole "realism" question comes down to "realism" vs cost. Given the current state of DCS I'd rather they worked on fixing a bunch of more important stuff (VR :) ) than spend time on an improved radar model right now. I'm sure whatever RCS values the DCS teams have are taken from some source and are a 75% solution IMO. To get another 10% more "realistic" would be a ton more work for not much return.

[falcon_120]

I think for me, the whole "realism" question comes down to "realism" vs cost. Given the current state of DCS I'd rather they worked on fixing a bunch of more important stuff (VR :) ) than spend time on an improved radar model right now. I'm sure whatever RCS values the DCS teams have are taken from some source and are a 75% solution IMO. To get another 10% more "realistic" would be a ton more work for not much return.

I get your point, and i agree, there are more important things to address. Anyhow I hope that when the right time comes they can make some small upgrades like the one proposed, not too complicated but also realistic.

 

Enviado desde mi SM-G950F mediante Tapatalk

[Harlikwin]

Well, I'm used to having to take complicated real world phenomenon and proposing simple explanations/approximations. :)...

[GGTharos]

Aspect based RCS and stores added RCS could be simulated. It would be simplified and it shouldn't take a toll on the CPU. It would represent the general behavior of RCS.

[drPhibes]

This topic triggered my curiosity a bit, so I made a crude model of the AGM-88 and ran a simple monostatic RCS simulation at 3GHz (S-band) in the horizontal plane (θ = 90°, φ = 0-360°). The front aspect (φ = 0°) is clearly wrong since the whole missile is simulated as a perfect electric conductor, while the real missile has a dielectric radome and an antenna inside. The actual φ = 0° result would probably be more like the rear aspect (φ = 180°).

 

[GGTharos]

What software did you use?

 

In any case, while you are correct, I think the RCS is probably going to be less than 5dbsm head-on.

[drPhibes]

Altair FEKO.

[GGTharos]

Thanks :) I saw some papers which show fairly high head-on RCS but their models are very simplified. The trick with missiles is that the antenna itself may or may not be pointed at the aircraft that's painting the missile. With an ARM, the antenna itself may be hemi-spherical (convex, not concave).

[Harlikwin]

So how long did that take to run? and I assume you ran the vertical slices too? Could you post a 3d blob graph?

[Eihort]

Ooo! Ooo! Dr. Dr.! Can I see a bug splat for X-band please? Around 9gigish?