S-300 clamshell SR broken

[Buzzer1977]

S-300 clamshell search radar is broken. A S-300 site with a clamshell search radar won't fire. See attached track, mission file, debrief and dcs.log.

S-300-clamshell-bug.log S-300-clamshell-bug.miz S-300-clamshell-bug.trk dcs.log

[Northstar98]

Not sure what's going on here, the C-17A at least appears to be in range, within the elevation limits (defined as -15°, +60° for the Clam Shell, I make the C-17A at 15°), above the minimum radial velocity (defined as 15 m/s for the Clam Shell, I make it ~40 m/s). The other targets may be beyond what the 5V55R missile is capable of intercepting.

I have been able to get an S-300PS battalion to work, even when there's only a Clam Shell for acquisition (see my track below). In that case, whatever the problem is I don't think it's necessarily related to the Clam Shell.

I'm not sure if DCS models it but your site is laid out quite strangely, IRL you have a group of launchers consiting of a 5P85S (TEL C) and up to 2 5P85D (TEL Ds) with up to 4 groups ber battalion. The launching group must be located within 120 m of the fire control radar and the 5P85Ds can't be located more than a few metres away from the 5P85S (the limitations come from length of the data links and cables) - see here and here.

Perhaps it might be worth switching the Clam Shell for a Big Bird and seeing if you observe the same results and maybe change the other aircraft so they are approaching the site. If that doesn't work, I'd try a more real-world S-300PS layout (an example can be found below).

S-300PS_clamshell_test.miz S-300PS_clamshell_test.trk

[Ironhand]

22 hours ago, Buzzer1977 said:

S-300 clamshell search radar is broken. A S-300 site with a clamshell search radar won't fire. See attached track, mission file, debrief and dcs.log.
 

S-300-clamshell-bug.log 75.45 kB · 2 downloads S-300-clamshell-bug.miz 19.04 kB · 0 downloads S-300-clamshell-bug.trk 104.7 kB · 1 download dcs.log 252.04 kB · 1 download

The mission is bugged. There was an issue with the F-16 (?). There was something weird going on with it when I highlighted it. Anyway, I removed it and the SAMs launched. I had also coincidentally moved the two remaining aircraft further out. Not sure if that also had something to do with it but I doubt it.

[Ironhand]

20 hours ago, Ironhand said:

The mission is bugged. There was an issue with the F-16 (?). There was something weird going on with it when I highlighted it. Anyway, I removed it and the SAMs launched. I had also coincidentally moved the two remaining aircraft further out. Not sure if that also had something to do with it but I doubt it.

Never mind. When I checked the mission, I didn’t realize there were multiple S-300 sites scattered around the periphery of the Caucasus map. I only saw the units in the Crimea. I thought those were the units I was watching in F8. It was another set of units.

It may just be that, in the simplified world of the DCS SAM environment, the 76N6 Clam Shell can’t stand on its own. For that matter, since it’s a specialized low altitude search radar, I doubt it’d ever be fielded on its own without a Tin Shield or similar search radar along. 

Edited March 15, 2024 by Ironhand

[Buzzer1977]

6 hours ago, Ironhand said:

Never mind. When I checked the mission, I didn’t realize there were multiple S-300 sites scattered around the periphery of the Caucasus map. I only saw the units in the Crimea. I thought those were the units I was watching in F8. It was another set of units.

It may just be that, in the simplified world of the DCS SAM environment, the 76N6 Clam Shell can’t stand on its own. For that matter, since it’s a specialized low altitude search radar, I doubt it’d ever be fielded on its own without a Tin Shield or similar search radar along. 

 

I added all combinations of SR/TR for the S-300 on the map. All with the same layout, and the same targets circling overhead. Only the SAMs with a clamshell SR haven't even been able to fire once.

[Whiskey11]

10 hours ago, Buzzer1977 said:

I added all combinations of SR/TR for the S-300 on the map. All with the same layout, and the same targets circling overhead. Only the SAMs with a clamshell SR haven't even been able to fire once.

The way DCS SAM sites work is EACH site requires the appropriate search radar(s) and track radars IN the group.

 

The S-300PS in game requires, at a minimum, the Flap Lid (truck or mast) and either the Big Bird or mast Tin Shield (trailer one from the S-200 doesn't work).  

 

If you don't have either the mast mounted Tin Shield or the Big Bird in the group, you'll get strange behavior like the site sometimes working if the aircraft falls within the search envelope of the Flap Lid, but not the Clam Shell.

 

Hopefully ED will give us more realistic IADS behavior so we don't have those dependencies and we can more accurately represent how those units are deployed IRL.

[Northstar98]

On 3/15/2024 at 12:30 PM, Ironhand said:

It may just be that, in the simplified world of the DCS SAM environment, the 76N6 Clam Shell can’t stand on its own. For that matter, since it’s a specialized low altitude search radar, I doubt it’d ever be fielded on its own without a Tin Shield or similar search radar along.

This doesn't appear to be the case, as per my track. In that I was able to get the site to engage an aircraft with only the Clam Shell and Flap Lid present as far as radars are concerned.

If I remove the Clam Shell from my mission, the site doesn't engage. Even if I place the Flap Lid such that the target would be within it's expected scan volume.

IRL, an S-300PS battalion usually only has the Flap Lid and a Clam Shell on site, the Big Bird or Tin Shield would be located at an EWR site, providing acquisition and battle management for multiple S-300 battalions. However, you can find examples where they appear to be colocated together (I've found a few such examples on the Kola Peninsula). Of course that's more IADS like functionality which DCS doesn't really support, meaning each battalion essentially operates independently and must have its own acquisition radars.

In any case, the Clam Shell, as defined in its .lua has a scan volume between -15° to +60° in elevation and ±180° azimuth, a detection range of 120 km and a minimum radial velocity of 15 m/s.

8 hours ago, Whiskey11 said:

If you don't have either the mast mounted Tin Shield or the Big Bird in the group, you'll get strange behavior like the site sometimes working if the aircraft falls within the search envelope of the Flap Lid, but not the Clam Shell.

In my track, the target shouldn't be within the scan volume of the Flap Lid and it engages the target, it still does if I rotate the FCR such that target is within where I'd expect the sector the Flap Lid can scan without rotating. If I remove the Clam Shell though, the target isn't engaged and the site doesn't appear to react at all.

Note that the .lua sensor definitions do not tell the entire story for the scan volume of a radar. While I have seen radars that have a ±180° azimuth limits in the files (i.e. 360°) - such as the 5N63S Flap Lid B and 9S35 Fire Dome. When I've set up the latter such that it's operating completely independently (no Snow Drift) it was only able to acquire targets within a certain sector, as would be expected IRL.

Definitely with you on the trailer mounted Tin Shield, which has a whole host of wrong with it (not an appropriate S-200 radar, can't be used in either of the 2 roles it has IRL, despite the ease the changes to make it so would be).

Edited March 16, 2024 by Northstar98