Chaff is causing false targets to appear in TWS.

[KenobiOrder]

This is from the "Beyond visual range" mission on PG that comes with the tomcat. I decided to do it after 2.7 to see if there was any improvement in the false contact problem.

 

Tacview-20210422-180437-DCS-F-14B_IA_PG_BVR.zip.acmi

 

I picked this mission because it is simple and only deals with two targets. Of particular note in this tacview is that the targets never enter the notch. There was much discussion before that part of the problem with the false contacts was how the currently implemented radar logic was dealing with targets as they enter the beam. That would appear to not be the entire issue, as demonstrated here.

 

 

There are only two planes actually in the air in front of the radar. Yet somehow it has generated about 8 false targets with crazy velocities to the beam. One of the targets in the tacview does not even maneuver. The one that does maneuver only does a diagonal dive to the left while popping chaff. Closure velocity compared to ground speed is well above the velocity gate at all times.

Edited April 24, 2021 by KenobiOrder

[Lurker]

Shot in the dark here, but could the AI chaffing be responsible for the false radar returns? The AI is famous for dispensing chaff even if "unaware" of being shot at in TWS. (Not saying it's not a bug, just curious to what's going on here)

Edited April 23, 2021 by Lurker

[Noctrach]

3 hours ago, Lurker said:

Shot in the dark here, but could the AI chaffing be responsible for the false radar returns? The AI is famous for dispensing chaff even if "unaware" of being shot at in TWS. (Not saying it's not a bug, just curious to what's going on here)

 

Chaff is invisible to aircraft radar (dont exist as game objects) so wouldnt be able to influence TWS ^^ its purely a diceroll on the missile + particle effect

[Skysurfer]

I think this has something to do with the "new" TWS logic/code as it only started happening after TWS-A was released. I recall the entire year before that there were no such issues with TWS or RWS - never seen duplicate contacts, let alone a trail of tracks before that. 

[KenobiOrder]

I redid the test without chaff and this appears to be the source of the problem as when chaff is removed i wasnt getting false targets. So the bug would appear to be related to chaff, as the AWG-9 should be filtering out the chaff via doppler and other gates.

[TLTeo]

Knowing how chaff is implemented in DCS, that is beyond bizarre!

Edited April 24, 2021 by TLTeo

[dundun92]

Well if that is indeed the case, this is not too far from realistic. It may be ovedone/implementation may not be quite right, but the basic effect of chaff messing with radar tracks is realistic especially for a radar of its era. Im really surprised its modeled though.

[KenobiOrder]

15 minutes ago, dundun92 said:

Well if that is indeed the case, this is not too far from realistic. It may be ovedone/implementation may not be quite right, but the basic effect of chaff messing with radar tracks is realistic especially for a radar of its era. Im really surprised its modeled though.

Not really. The chaff would slow down rapidly below the Doppler gate and be filtered out. The chaff would take a moment to bloom to have any effect, and by that time it would be too slow to matter. If by some extreme luck a chaff bundle bloomed, and happened to be in the resolution cell of the radar with sufficient velocity, it would be filtered out through the use of other gates. For example, there would be a huge spike in RCS too large to be a real target, and the radar would simply ignore it for the brief few moments its velocity was great enough to matter.

[WelshZeCorgi]

Could the same thing might be happening with PHs? If the seekers on the PH use PD, they're still getting decoyed by chaff that as you say, do not maintain the speed necessary to create the Post-doppler effect required for the PH to see the chaff, yet the PH still home in on them. 

 

Edit: and before "that would make PH OP!!!", remember that PD requires sufficient closure speed, so you could sensor defeat the PH simply by turning into the notch, not even deploy a single cartridge of chaff, and become completely invisible to the active PH. 

 

Edited April 24, 2021 by WelshZeCorgi