U22A EM signal recording seems to be broken

[Leviathan667]

Hi,

I noticed over the course of the last few weeks in several missions the pod would only record red air emitters and completely ignore land based red emitters.

So I made a custom mission to test the U22/A ability to record land based red signals.

It did not record any even though I’ve been painted several times by SAM systems and one of them fired at my plane.

Find attached the info file, trk file, tacview file and miz file.
 

Tacview-20230325-152210-DCS-TEST_ELINT_VIGGEN 2.zip.acmi Leviathan ELINT2.trk TEST_ELINT_VIGGEN 2.miz ELINTData 25-03-2023.info

[RubberDogSh1tOutOfHKG]

Sorry for Necroposting, but I have a similar enough issue I think.

On the South Atlantic map I get completely invalid elint data, doesnt matter what patterns, heights, emitters whatever I do. The Coords are way off.
Same gear on the Syria Map, and I get good data.

Map issue, or something else?

[zerO_crash]

Same problem. The targets are completely off position after having done a ELINT mission. Question is whether this is intentional (what the technology of the day allowed), or whether this is indeed a bug.

 

Confirmed with taking a navigation fix on beforehand, so as to rule out drifting of NAV.

[Rudel_chw]

53 minutes ago, zerO_crash said:

Same problem. The targets are completely off position after having done a ELINT mission.

 

I'm currently re-learning the Vigggen and will soon study its ELINT abilities, I will post here any findings that I get.  I find it curious that no one from Heatblur acknowledged the bug report made by the OP, I know that they must be busy with the Phantom, but at least one person of the team should be maintaining the Viggen, isnt it?  

 

Edit: here is a very recent video, by @deephack, on the Syria Map and the ELINT feature seems to work normally:

 

 

 

Edited April 24, 2024 by Rudel_chw

[zerO_crash]

21 minutes ago, Rudel_chw said:

 

I'm currently re-learning the Vigggen and will soon study its ELINT abilities, I will post here any findings that I get.  I find it curious that no one from Heatblur acknowledged the bug report made by the OP, I know that they must be busy with the Phantom, but at least one person of the team should be maintaining the Viggen, isnt it?  

 

Edit: here is a very recent video, by @deephack, on the Syria Map and the ELINT feature seems to work normally:

 

 

 

 

Well, actually, at 05:45, he mentions that one of the points was off. He doesn't show any map scale, but it looks 20-30km ish by eye measure (it can be measured on the map though). One site didn't even get picked up (SA-11).

 

My experience, is that in a dense area with multiple theatre-level (division) SAM sites, the coordinates can sometimes be between, or completely outside of the area. I've had results ranging from approx. 18-22km away from actual SAM-site, to as much as 70-80 km and more, away.

 

That's why I ask whether this is a actual bug, or simply very advanced modelling of radar waves (electromagnetic)/lack of accuracy of the system. Not sure why Heatblur won't come with a comment on this... There are tracks above, if they need that.

[Sideburns]

I did some experiments with this about two years back against land SAMs and vessels, it was working then but even under ideal conditions (single emitter, non complicated environment, full fly around) it was not particularly accurate, perhaps at best 5-10km. But it did feel representative of a system of this era (i.e. based on INS not GPS, repurposing a directional jammer pod to act as a sensor). In a more complex environment the results got a lot more inaccurate.

I will try to test again soon.

Edit: It is probably also worth noting at some point the online tools for reading the U22 files broke. Combatflight also has the ability to read these files, and at the end of the day the U22 files are basically just a text file so you can read them yourself to check the DCS sim output before a potentially broken mapping tool reads them.

Edited April 25, 2024 by Sideburns

[Sideburns]

Finally got a chance to retry this feature, a few key notes for correct operation:

• Make sure the radar system is actually emitting and can be picked up by the Viggen (a few SAMs I tried didn't appear to power on, DCS things I guess)
• Make sure you are carrying the U22/a pod, the U22 doesn't have the silent listening feature
• The body of the jet seems to mask radar signals from the pod, the pod typically is mounted on the right side, also it picks stuff up in the frontal region only and is more sensitive than the RWR (picks things up further out). When the pod is receiving something the "MOTVERK" light will flash.
• You ideally want to fly around a fair bit and from a few different angles towards the SAM with accurate nav system for best results
• Return to base, land and put the master mode in "BER", this is a post flight data processing / extract mode.
• Check in your saved games folder, e.g. C:\Users\user\Saved Games\DCS_AJS37 for ELINTData.info, it should have some content in like

ELINT:

Emitter: 1
Freq: A PRF: 1800
First signal: 8:2:20 Last signal: 8:4:22
Sequence broadca: 0.1s Silent: 1.49012e-09s
NW: 41:50:23 041:43:48 SE: 41:46:48 042:28:36

Combatflite is still capable of importing and showing ELINT files, but you have to go to options and select show ELINT as well as importing the file. And yeah, this wasn't very accurate given the SAM was based at Batumi river mouth xD This works about as well as it ever has done, you have to fly big laps and boxes around the area to get best results, and even then they aren't anywhere near HTS levels of accurate. I have tried this feature at low alt not at high alt. I also unfortunately don't have the Falklands map to try, but I am aware there are some hacks to get southern hemisphere working for the Viggen nav system. Perhaps these have not carried across to the ELINT feature.

Edit: Also noticed, if you fly a mission with the ELINT feature and land it will then autogenerate an ELINT cartridge for a follow on mission based on the ELINT results.

 

Edited May 3, 2024 by Sideburns

[Rudel_chw]

1 hour ago, Sideburns said:

a few key notes for correct operation:

 

Hi, Thanks a lot for sharing your notes 

[zerO_crash]

On 5/3/2024 at 7:47 PM, Sideburns said:

Finally got a chance to retry this feature, a few key notes for correct operation:

• Make sure you radar system is actually emitting and can be picked up by the Viggen (a few SAMs I tried didn't appear to power on, DCS things I guess)
• Make sure you are carrying the U22/a pod, the U22 doesn't have the silent listening feature
• The body of the jet seems to mask radar signals from the pod, the pod typically is mounted on the right side, also it picks stuff up in the frontal region only and is more sensitive than the RWR (picks things up further out). When the pod is receiving something the "MOTVERK" light will flash.
• You ideally want to fly around a fair bit and from a few different angles towards the SAM with accurate nav system for best results
• Return to base, land and put the master mode in "BER", this is a post flight data processing / extract mode.
• Check in your saved games folder, e.g. C:\Users\user\Saved Games\DCS_AJS37 for ELINTData.info, it should have some content in like

ELINT:

Emitter: 1
Freq: A PRF: 1800
First signal: 8:2:20 Last signal: 8:4:22
Sequence broadca: 0.1s Silent: 1.49012e-09s
NW: 41:50:23 041:43:48 SE: 41:46:48 042:28:36

Combatflite is still capable of importing and showing ELINT files, but you have to go to options and select show ELINT as well as importing the file. And yeah, this wasn't very accurate given the SAM was based at Batumi river mouth xD This works about as well as it ever has done, you have to fly big laps and boxes around the area to get best results, and even then they aren't anywhere near HTS levels of accurate. I have tried this feature at low alt not at high alt. I also unfortunately don't have the Falklands map to try, but I am aware there are some hacks to get southern hemisphere working for the Viggen nav system. Perhaps these have not carried across to the ELINT feature.

Edit: Also noticed, if you fly a mission with the ELINT feature and land it will then autogenerate an ELINT cartridge for a follow on mission based on the ELINT results.

 

 

That is all as per initial mention of the feature. I always take a clean AJS-37, and fly in a SR-71 type of arc, where the underside of the Viggen is exposed towards the radar, so as to not mask the U22/a pod. Still, as you see yourself, the actual accuracy of the pod is somewhat poor.

 

I don't mind that at all. I would, however, like to get an exact/semi-exact answer on whether this is in the ball park of the original capability. If that's how it was, fantastic, we'll work with that. I just don't want to alter the mission-style to something that might prove a bug.

 

Again, a formal comment would be nice.

 

I still see value in this system, such as determining the actual type of SAM, as well as it's rough location. It just means that you can't build specific SEAD missions based on ELINT alone. Also, the kneeboard way of reading elint, is perfect, especially for VR. It is preferred above restarting DCS or such.

Edited May 19, 2024 by zerO_crash