correct as is SA FRIEND filter and SA/RDR ATTK EW symbols

[Ahmed]

Hi,

 

The SA FRIEND sensor filter acts as some sort of "magic IFF" tool when both coalitions have the same aircraft.

 

With the default "FRIEND OFF" selection, in a setup like in the attached track, despite both emitters being virtually the same emitter and triggering the same RWR indications, the SA and RDR ATTK still filter them and only display the EW symbol for the hostile Hornet.

magic.trk

[Hulkbust44]

On 7/3/2021 at 5:27 AM, Ahmed said:

Hi,

 

The SA FRIEND sensor filter acts as some sort of "magic IFF" tool when both coalitions have the same aircraft.

 

With the default "FRIEND OFF" selection, in a setup like in the attached track, despite both emitters being virtually the same emitter and triggering the same RWR indications, the SA and RDR ATTK still filter them and only display the EW symbol for the hostile Hornet.

magic.trk 25.44 kB · 5 downloads

The EW format also shows CIT data, do you have any documentation saying this is wrong? 

[Beamscanner]

3 hours ago, Hulkbust44 said:

The EW format also shows CIT data, do you have any documentation saying this is wrong? 

He's not talking about real IFF.. 

 

He's saying that the RWR shouldn't be able to say: 'This APG-73 is friendly; so I wont show it, and that APG-73 is enemy so I will display it'

 

The RWR can ID the radar.. It cannot identify if the person working the radar is a nice guy who wont hurt you. 

 

[BIGNEWY]

It should only indicate friend with a positive IFF response 

[dorianR666]

7 minutes ago, BIGNEWY said:

It should only indicate friend with a positive IFF response 

um, how can RWR do an IFF interrogation?

[Ahmed]

 

4 hours ago, dorianR666 said:

um, how can RWR do an IFF interrogation?

It can't.

 

The whole issue of this thread is that, as Beamscanner clarified, the DCS Hornet will display a hostile APG-73, but filter friendly APG-73, when both coalitions have the same aircraft.

 

So, while the RWR in-game still displays the same indications for both, the SA/ATTK RDR format FRIEND sensor filter has not been coded to account for, and give sensible results, for this particular scenario in which both coalitions have the same aircraft. While this is by all means a minor issue, it has the potential to be an exploitable one for those players who focus on PVP.

[Hulkbust44]

 
It can't.
 
The whole issue of this thread is that, as Beamscanner clarified, the DCS Hornet will display a hostile APG-73, but filter friendly APG-73, when both coalitions have the same aircraft.
 
So, while the RWR in-game still displays the same indications for both, the SA/ATTK RDR format FRIEND sensor filter has not been coded to account for, and give sensible results, for this particular scenario in which both coalitions have the same aircraft. While this is by all means a minor issue, it has the potential to be an exploitable one for those players who focus on PVP.

Um, what not? just think about it. Someone on your side sends out an interrogation signal to your aircraft. Your aircraft recognizes the incoming mode 4 as it is friendly and sends a response. Your jet know knows that to that specific F-16 is friendly because you're talking the same language. Another F-16 picks you up, but as it is part of the opposing coalition, you can't understand his mode 4 request, so his nails gets labeled by your aircraft as unk/hostile.

I don't see the issue with this.

Mobius708

[dorianR666]

How is the IFF transponder going to detemine the exact azimuth of the incoming IFF request to correlate it precisely with RWR nails?

 

Also the IFF transmitter isnt emitting continously, so if what you say was true, the friendly RWR nails would appear on SA for at least a while.

 

EDIT: Furthermore I'd like to add that on DCS F-14 it works the way Beamscanner and Ahmed expect it to work. That means, if there is an aircraft type thats used by both sides in a mission, then neither friendly nor hostile aircraft of that type are considered as friendly by RWR FRIEND filter.

Edited August 4, 2021 by dorianR666

[Hulkbust44]

Also the IFF transmitter isnt emitting continously, so if what you say was true, the friendly RWR nails would appear on SA for at least a while.

They do, but the SA filter is set to Friend OFF by default.

Mobius708

[Hulkbust44]

How is the IFF transponder going to detemine the exact azimuth of the incoming IFF request to correlate it precisely with RWR nails?
 

I would have a very hard time believing that's not possible. It wouldn't make sense with the technology available. Hell, why wouldn't the aircraft be able to correlate an RWR nails with an offboard trackfile?



Now again we must remember that DCS basically dosen't model IFF at all. Regardless of what the interrogated aircraft has their IFF set to, they will always return friendly if they are apart of your coalition. That part is wrong.

Mobius708

[Spectre1-1]

3 hours ago, Hulkbust44 said:

 

 

I would have a very hard time believing that's not possible. It wouldn't make sense with the technology available. Hell, why wouldn't the aircraft be able to correlate an RWR nails with an offboard trackfile?



Now again we must remember that DCS basically dosen't model IFF at all. Regardless of what the interrogated aircraft has their IFF set to, they will always return friendly if they are apart of your coalition. That part is wrong.

Mobius708
 

 

For the record the hornet can corrolate CIT RWR and offboard tracks, its part of what MSI does.

[Hulkbust44]

For the record the hornet can corrolate CIT RWR and offboard tracks, its part of what MSI does.

Yeah, exactly, thanks for the confirmation. I wish MSI actually functioned in DCS. The many separate systems are very annoying.

Mobius708

[Ahmed]

  

4 hours ago, Hulkbust44 said:

Um, what not? just think about it. Someone on your side sends out an interrogation signal to your aircraft. Your aircraft recognizes the incoming mode 4 as it is friendly and sends a response. Your jet know knows that to that specific F-16 is friendly because you're talking the same language. Another F-16 picks you up, but as it is part of the opposing coalition, you can't understand his mode 4 request, so his nails gets labeled by your aircraft as unk/hostile.

I don't see the issue with this.

Mobius708
 

My friend, what does IFF have to do with the RWR? You seem to be taking a lot of creative liberties in your contributions to this thread.

 

31 minutes ago, Spectre1-1 said:

For the record the hornet can corrolate CIT RWR and offboard tracks, its part of what MSI does.

Thanks, I actually was unsure if this could be a capability of MSI, this is why, if you check the track, I turned off EPLRS for the friendly AI hornet and never interrogted it, so as to isolate that possibility of MSI having any impact on the bug report.

 

There is definitely a simplification in the code (a simple coalition check) that make the game not account for this case. However, this has now been marked "correct-as-is" (I'd suggest "working-as-intended" instead, as to stay credible), so not much more to say about it.

Edited August 4, 2021 by Ahmed

[Hulkbust44]

  
Thanks, I actually was unsure if this could be a capability of MSI, this is why, if you check the track, I turned off EPLRS for the friendly AI hornet and never interrogted it, so as to isolate that possibility of MSI having any impact on the bug report.
 
There is definitely a simplification in the code (a simple coalition check) that make the game not account for this case. However, this has now been marked "correct-as-is" (I'd suggest "working-as-intended" instead, as to stay credible), so not much more to say about it.

In the Hornet most all systems are connected. The ASPJ, RWR receivers, MSI, and even the HARM seeker if equipped all work together. I'm talking about the semi circle and chevrons on the EW format, not the SA format RWR filter. The physical knob on the ALE-47 panel for filters isn't even modeled yet.

Just saying how all they systems contribute to display IFF information on the EW format.

Mobius708

[Wizard_03]

It's called sensor fusion and it's a big advantage over older aircraft like the tomcat.

[Ahmed]

But you understand that there is no way for the hornet in the attacked recorded track, (no IFF, no DL), to determine that one of them is friendly and the other one is not, right?

 

In any case, time to put this behind as ED have already decided not to fix this and is, arguably, a minor thing. Glad to hear that Heatblur actually made it work the right way though.

[Jak525]

RWR is not correlated with MSI trackfiles, you get the nails at the top of the ATTK/AZEL and around the SA. IFF transponder is though. But the RWR is separate.

Edited August 6, 2021 by Jak525

[Beamscanner]

Just bc something hypothetically could, doesn't mean it does.

 

The angular resolution of the CIT array and RWR is not similar, or especially fine. While CIT has range, RWR tracks do not. So you can only corelate the two in azimuth. With a bit of critical thought, you would realize that nearby friendlies down the same clock position (again the azimuth resolution would come down to the lowest common denominator; the RWRs poor angular resolution) as a threat, would hide said threats emissions.. 

 

Likely response: But the enemies radar is different, only apply this filter to friendly type radars. (ex. never hide a 29 spike)

 

My counter response:

1. You dont know the mis-ID percentage of a real RWR.
2. Part of a pilots bogey -> Bandit ROE cert, includes IFF, RWR, NCTR, "red force line", datalink, off-board calls, etc. Keeping CIT and RWR separate ensures a higher level of certainty that the potential threat is not a friendly.
3. The RWR priority filter doesn't hide emitters. It alters the ranking of RWR tracks.

 

Hypothetically, IFF correlation with RWR could work if all of the criteria could be met:

• RWR had high angular resolution (~1 degree)
• CIT had high angular resolution (~1 degree)
• RWR correct signal identification > 99%
• BLUFOR and REDFOR didn't have overlapping Radar parameters
• CIT cannot be spoofed or malfunctioning
• The enemy could never know of this filter, as they could take advantage of it.

 

 

 

Edited August 6, 2021 by Beamscanner