Dynamic threat zone based on the selected flight's average RCS and flight profile

[upyr1]

Another mission editor suggestions. When we click on a flight the threat and detection zones should change based on the aircraft's RCS and flight profile at the current waypoint. I don't know how DCS models RCS but I figure that in real life it would change based on angle- so it should be the average RCS. 

[Tippis]

2 hours ago, upyr1 said:

I don't know how DCS models RCS but I figure that in real life it would change based on angle- so it should be the average RCS. 

Oh, that's easy: it doesn't.

It's a fixed “reflection” stat that is compared against a radar system's “reflection limit” to see if they can see the thing or not.

[upyr1]

2 minutes ago, Tippis said:

Oh, that's easy: it doesn't.

It's a fixed “reflection” stat that is compared against a radar system's “reflection limit” to see if they can see the thing or not.

So it should be easier to set up dynamic threat zones. 

[Northstar98]

1 hour ago, Tippis said:

Oh, that's easy: it doesn't.

It's a fixed “reflection” stat that is compared against a radar system's “reflection limit” to see if they can see the thing or not.

Wait, does that mean that so long as the target RCS > the reflection limit, said target will be detected at whatever the maximum instrumented range of the RADAR? And it's not actually calculating detection distance for x RCS based on the RADAR equation?

Because if so, that's pretty alarming...

 

And if this is the case, that would make the wish pretty much irrelevant, because the detetction distance would have to vary based on RCS in order to do this.

I know player aircraft RADARs factor RCS, but I know AI RADARs are simpler.

Edited April 15, 2022 by Northstar98

[GGTharos]

2 hours ago, Tippis said:

Oh, that's easy: it doesn't.

It's a fixed “reflection” stat that is compared against a radar system's “reflection limit” to see if they can see the thing or not.

It does.  It uses the radar equation.   Perhaps what you mean to say is that it does not model complex RCS.

[upyr1]

31 minutes ago, GGTharos said:

It does.  It uses the radar equation.   Perhaps what you mean to say is that it does not model complex RCS.

If we have a simple rcs model then it would be easy to implement that part. Especially if it is a percentage 

[WHOGX5]

2 hours ago, GGTharos said:

It does.  It uses the radar equation.   Perhaps what you mean to say is that it does not model complex RCS.

Yeah, I think that's what he meant. Last I checked, RCS in DCS is a static numerical value per aircraft. In real life, as an example, pretty much every modern fighter jet has a much bigger radar cross section when viewed from the sides compared to from the front or rear. Here you can see an example of an extremely simplified RCS calculation from the 3D model of a Su-57: https://www.researchgate.net/figure/The-XY-view-of-the-model-and-RCS-dBsm-at-25-GHz-in-the-azimuth-plane-with-Az-11360_fig4_345140504

Also, here's a post containing a picture where you can see the RCS and IR values for pretty much all DCS units in patch 2.5.6:

[Tippis]

12 hours ago, Northstar98 said:

Wait, does that mean that so long as the target RCS > the reflection limit, said target will be detected at whatever the maximum instrumented range of the RADAR? And it's not actually calculating detection distance for x RCS based on the RADAR equation?

Because if so, that's pretty alarming...

It's not quite as binary as that, other than the reflection limit providing a lower bound below which a radar can never see its targets, but those are low enough that it only ever effects incoming weapons for the purpose of missile defence (the SA-15 has a ridiculously low reflection limit, which is why it is able to engage pretty much anything slung its way). For larger things and/or for particularly crappy radar systems, you can occasionally see some reduction in detection range but most of the time, it's a case of “oh no, I'm being detected at 65nm inside this nominal 70nm threat zone”.

All planes are spherical cows and while all sensors have some attenuation at extreme ranges, in most instances it's a largely forgettable effect and you're better served by trying to stay within the notching closure speed bracket (usually <10–15m/s radial velocity relative to the sensor). And that's if we're dealing with a class of objects that the sensor is even allowed to detect to begin with — like how gliding bombs can be detected because they're technically missiles in the code, whereas free-fall bombs can't be because they're classed as… well… bombs.

But on the other end of the scale, you have some really funny effects caused by the same simplifications, like IR SAM systems trying to intercept MLRS rockets because they, too, belong to that “allowed to be detected” missile class and have a signature stat that the IR sensor can resolve. So yeah, sensors in DCS are a bit… interesting.

Edited April 16, 2022 by Tippis

[Northstar98]

1 hour ago, Tippis said:

It's not quite as binary as that, other than the reflection limit providing a lower bound below which a radar can never see its targets, but those are low enough that it only ever effects incoming weapons for the purpose of missile defence (the SA-15 has a ridiculously low reflection limit, which is why it is able to engage pretty much anything slung its way). For larger things and/or for radar systems, you can occasionally see some reduction in detection range but most of the time, it's a case of “oh no, I'm being detected at 65nm inside this nominal 70nm threat zone”.

Ahh okay then, so long as it's using the RADAR equation (or an abbreviated form of it) is being considered then I'm good.

I am aware of numerous other simplifications as far as DCS sensors go, I just didn't think it got as simplified as if RCS > x limit -> object detected, but pleased to hear that isn't the case.

1 hour ago, Tippis said:

All planes are spherical cows and while all sensors have some attenuation at extreme ranges, but in most instances it's a largely forgettable effect and you're better served by trying to stay within the notching closure speed bracket (usually <10–15m/s radial velocity relative to the sensor). And that's if we're dealing with a class of objects that the sensor is even allowed to detect to begin with — like how gliding bombs can be detected because they're technically missiles in the code, whereas free-fall bombs can't be because they're classed as… well… bombs.

Yeah, I'm aware that everything with an RCS value only has a single value regardless of aspect or configuration (unlike say, C:MO, which does both).

Though I'm getting a little confused if it's a largely forgettable effect - in the ideal RADAR equation received power is directly proportional to RCS - I know this is considered for player RADARs but I'm not too sure if that goes for the AI as well.

Unless you're saying its a largely forgettable effect in practice (as I know a lot of RADARs in DCS have maximum ranges far below that of their true instrumented ranges).

1 hour ago, Tippis said:

But on the other end of the scale, you have some really funny effects caused by the same simplifications, like IR SAM systems trying to intercept MLRS rockets because they, too, belong to that “allowed to be detected” missile class and have a signature stat that the IR sensor can resolve. So yeah, sensors in DCS are a bit… interesting.

Yeah, I've definitely seen some of that weirdness.

Like the SA-15 attempting to shoot down APKWS rockets as they're classified as a missile, but not giving a single toss about much larger rocket artillery, or things like the AGM-62.

 

And don't get me started on ships...

Edited April 16, 2022 by Northstar98