SA-6 Max Altitude

[Swift.]

In the DCS Encyclopaedia, the SA-6 system is described as having a maximum engagement altitude of 14000m (~46000ft), this number correlates with the value stated on the wikipedia page for the same system.

In DCS gameplay, the SA-6 will not engage above 26,000ft. (Track attached). This number is suspiciously similar to the design spec of the SA-6 system where its stated the missile was required to reach at least 23,000ft. Or maybe its just a typo between 26k and 46k somewhere along the line.

In any case, the SA-6 system should be capable of engaging targets up to 46,000ft as DCS's own Encyclopaedia states.

SA6Altitude.trk

[Northstar98]

The main issue I see is 2-fold:

1. What variant of the SA-6 do we have? (seems to imply 2K12M 'Kub-M', owing to 3M9M missile, though I can't find engagement envelope for this missile) it doesn't help that the new display names introduced in 2.7 were made more vague.
2. Specifications online are a nightmare, with sources providing contradictory information.

In the wikipedia page, that 14 km max. engagement altitude is listed for the 2K12M4 'Kub-M4', which can be thought of as a hybrid of the 2K12M3 'Kub-M3' and the 9K37 'Buk' system.

The 2K12M4 system fires 2 different missiles, there's the 3M9M3 from the 2K12M3 and the 9M38 from the 9K37.

The 3M9 missile has a maximum engagement altitude of 7 km with the 3M9M3 (and the 3M9M1) having a maximum engagement altitude of 8 km. However, with the so-called K-1 complex (whatever that is), these altitudes all extend to 12 km.

The 9M38 missile on the other hand, according to wikipedia, has a "flight altitude" of 14 km and Vestnik-PVO also states that the "affected area in height" ranges from 30 m to 14 km. So my guess is that the 14 km figure is actually for the 9M38 missile, and not any of the 3M9(Mx) missiles, and that the encylopedia is just copying off of wikipedia, without doing any other research.

However, basically every other source I've found states that the maximum engagement altitude for the 9M38 is 20 km, including, rather confusingly, wikipedia and Vestnik-PVO.

The SA-6 in DCS allegedly firing the 3M9M missile (which somehow has more range than the 3M9M1 missile, despite the encylopedia and range ring being more representative of a 3M9M3 missile).

And for the 3M9M3, the maximum engagement range is listed as 24 km for the 2K12M4 and 25 km for the 2K12M3, despite the 2 systems firing the same missile, using the same RADAR (1S91M3) and the same launcher (2P25M3, though the 9A38 seems to also have the ability to fire the 3M9M3). DCS' encyclopedia lists the maximum engagement range as 24 km, but the range ring in the mission editor has a radius of 25 km.

The 3M9 has a max. engagement range of 22 km and the 3M9M1 23 km, which seems to be consistsent.

Edited February 18, 2022 by Northstar98
grammar

[Kvek]

The max launch altitude of the sa-6 is around 26.000ft, like said before. But the missile will follow you to 37.000ft at least, keeping enough energy to hit you. I think (dont have evidence) that if the missile have the energy to reach 37.000ft, the system should fire at this altitude too.
Sorry for the english

Edited February 17, 2022 by Kvek

[Ironhand]

I recall watching a Russian documentary several years ago on the Kub system. The 3M9 was the missile it referenced. I bring it up because it noted something interesting. It stated that the system's max engagement altitude was 7 km. But later it noted that, when the battalion was controlled at the regimental level the regimental command and control system used increased the max engagement altitude to 12 km. It sounded as if the limiting factor was not the missile itself.

[Cmptohocah]

In this USSR documentary the max altitude is 23,5km.
 

 

Yet the same video lists KUB's missiles at max engagement altitude of 7km.

 

[Ironhand]

Different system. That's the "Krug" designed for high altitude interception. The Kub is the low to medium altitude system.

[Northstar98]

9 hours ago, Ironhand said:

I recall watching a Russian documentary several years ago on the Kub system. The 3M9 was the missile it referenced. I bring it up because it noted something interesting. It stated that the system's max engagement altitude was 7 km. But later it noted that, when the battalion was controlled at the regimental level the regimental command and control system used increased the max engagement altitude to 12 km. It sounded as if the limiting factor was not the missile itself.

So far from what I've found, the maximum engagement altitude goes from 7 km (8 km with the 3M9M1 and 3M9M3) to 12 km when used with the 'K-1 complex' (whatever that is).

[Ironhand]

23 minutes ago, Northstar98 said:

'K-1 complex”

Want to bet that’s the regimental level C&C system?

[Northstar98]

On 2/18/2022 at 1:53 PM, Ironhand said:

Want to bet that’s the regimental level C&C system?

Found what it is, the K-1 'Crab' (9S44) complex consists of either a P-40/1S12 [Long Track], P-15 [Flat Face A], P-18 [Spoon Rest D] or P-19 [Flat Face B], paired up with a PRV-9 [Patty Cake/Thin Skin A] or PRV-16 [Thin Skin B]. [1]

The C2 element is provided by a 9S416 (Ural-375D PBU), 5x 9S417 (ZIL-131/ZIL-157 PBU), a data-link/radio mast(?) "Grid-2K", as well as supporting units such as generators (AB-21), a survey vehicle (GAZ-69T) and a spare parts vehicle (9S441) [1] [2]

Apparently this system was replaced in the 70s with 9S468M1 'Polyana-D1', which can be read about in source [2].

I've also found where the maximum engagement altitude limitation comes from as well, it's a limitation of the 1S11 acquisition RADAR of the 1S91, it's altitude range is 30 to 7000 m (and presumably 30 to 8000 m for the 1S91M1/M3). Though this source gives a maximum engagament altitude for the 2K12M3 'Kub-M3' of 14 km (so perhaps the 1S91M3 can go up to 14 km? Or maybe that's just with the 3M9M3 missile, with the 1S91M3 being limited to 7-8 km, and using the regimental level systems to reach 14 km). [3]

It seems that with the SA-6 the P-40 [Long Track] RADAR is used. [3]

In any case, the maximum engagement altitude is correct as is, provided we have either the 2K12 or 2K12M1 or maybe the 2K12M3 (ED, please just name what variant 'x' is in the display names), as the above probably requires IADS functionality.

Edited February 23, 2022 by Northstar98
found significantly more information

[Ironhand]

56 minutes ago, Northstar98 said:

Found what it is, it's the P-40 RADAR

 Good work!

[Northstar98]

22 minutes ago, Ironhand said:

 Good work!

If you see my editand it's quite an edit (more of a complete rewrite), apologies, it's a bit more than the P-40, though source 3 mentions the P-40 as being used with the SA-6 (though there's the possibility for multiple RADARs, but the P-40 probably makes the most sense for us).

I've now managed to find sources which list the full composition.

Edited February 18, 2022 by Northstar98

[Ironhand]

1 hour ago, Northstar98 said:

Found what it is, the K-1 'Crab' (9S44)

Just watched the video Cmptohocah posted (re-watched, actually. I think that was the video I saw a few years ago). The regimental C&C system is referred to as the "Crab". Excellent sleuthing.

EDIT 2: I wonder if the acquisition radar's max altitude limitation is the result of the tracking radar being mounted above it. Would having it range higher interfere with the tracking side of things?

Edited February 18, 2022 by Ironhand
Edit 1: spelling

[Northstar98]

On 2/18/2022 at 3:26 PM, Ironhand said:

Just watched the video Cmptohocah posted (re-watched, actually. I think that was the video I saw a few years ago). The regimental C&C system is referred to as the "Crab".

Yes, that's the name also given in all 3 of the sources above.

Though in source 2 it states the system was outdated by the 70s and was replaced by the 9S468M1 'Polyana-D1', which entered service in 1975. Presumably it's compatible with the SA-6 (the source I used was for the SA-4), though it isn't mentioned in SA-6 specific sources.

On 2/18/2022 at 3:26 PM, Ironhand said:

Excellent sleuthing.

Thanks!

On 2/18/2022 at 3:26 PM, Ironhand said:

EDIT 2: I wonder if the acquisition radar's max altitude limitation is the result of the tracking radar being mounted above it. Would having it range higher interfere with the tracking side of things?

I doubt it, the 2 RADARs operate on different bands; the 1S11 acuisition RADAR operates in the C-band (0.5 - 1 GHz), and the 1S13 target-tracking & fire-control RADAR operates in the I-band (8 - 10 GHz) [1].

I'm not sure if the 1S11 is 2D or 3D capable, if its only 2D capable my guess is that it's due to the geometry of the antenna itself, and that the RADAR produces a fan-beam that only extends up to whatever maximum altitude.

If it's 3D capable, it might might either be due to the above, or a limited instrumented altitude range (though the latter sounds unlikely, given that the missile can engage targets at significantly higher altitudes). EDIT: It's probably 3D capable, owing to having a stacked feed, that produces stacked beams.

EDIT: in my 3rd source it states that the 1S11 produces a fan-beam that measures 1° in azimuth, and 20° in elevation.

According to the same source, the maximum engagement range for the system is 22 - 25 km (variant dependent, in DCS though the range ring is at 25 km, accurate for the 2K12M3 'Kub-M3'), assuming the lower edge of the fan-beam is at 0° elevation, that would give an absolute maximum altitude of a target to be detected of ~7.5 km (for a range of 22 km) and ~9 km (for a range of 25 km).

So it looks like it's due to the properties of the antenna and the beam it creates, rather than any interference.

But at the 1S11's maximum instrumented range of 70 km, that altitude increases to 25 km, at the 1S13's maximum range of 50 km (for an F-4 equivalent RCS), that altitude is approximately 18 km. So, theoretically, unless there's something else to it, you could acquire and track the target from further away, and then engage it at higher altitude once in range of the engagement range of the missiles. Though this would give the target plenty of warning, far before firing.

 

Suffice to say though, DCS AI RADAR and fire-control system fidelity doesn't go into the detail I've stated. In DCS, the 1S91 as treated as being a single RADAR, with a max. range of 70 km, and and elevation angle limit of -15 - 60° (which are presumably the elevation limits for the 1S13). [source]

Edited February 23, 2022 by Northstar98

[Swift.]

2 hours ago, Northstar98 said:

Found what it is, the K-1 'Crab' (9S44) complex consists of either a P-40/1S12 [Long Track], P-15 [Flat Face A], P-18 [Spoon Rest D] or P-19 [Flat Face B], paired up with a PRV-9 [Patty Cake/Thin Skin A] or PRV-16 [Thin Skin B]. [1]

The C2 element is provided by a 9S416 (Ural-375D PBU), 5x 9S417 (ZIL-131/ZIL-157 PBU), a data-link/radio mast(?) "Grid-2K", as well as supporting units such as generators (AB-21), a survey vehicle (GAZ-69T) and a spare parts vehicle (9S441) [1] [2]

Apparently this system was replaced in the 70s with 9S468M1 'Polyana-D1', which can be read about in source [2].

I've also found where the maximum engagement altitude limitation comes from as well, it's a limitation of the 1S11 acquisition RADAR of the 1S91, it's altitude range is 30 to 7000 m (and presumably 30 to 8000 m for the 1S91M1/M3). Though this source gives a maximum engagament altitude for the 2K12M3 'Kub-M3' of 14 km (so perhaps the 1S91M3 can go up to 14 km? Or maybe that's just with the 3M9M3 missile, with the 1S91M3 being limited to 7-8 km, and using the regimental level systems to reach 14 km). [3]

It seems that with the SA-6 the P-40 [Long Track] RADAR is used. [3]

In any case, the maximum engagement altitude is correct as is, provided we have either the 2K12 or 2K12M1 or maybe the 2K12M3 (ED, please just name what variant 'x' is in the display names), as the above probably requires IADS functionality.

 

IADS functionality or the optical guidance thing to work, so the crew *could* cue the engagement radar using optical means rather than the limits of the Straight Flush

[Northstar98]

Fro  my reading so far, the optical tracker is only supposed to be used as a back-up, when angle measurements using the 1S13 are degraded (with ranging coming from the 1S11) from jamming. AFAIK it's a 1st generation TV system.

And that optical system is undefined in DCS World, DCS treats it as if it doesn't exist (which is par for the course).

Though what I don't get, is that, theoretically, the acquisition RADAR can acquire targets at higher altitudes, so long as they're further away, I would've thought they'd be able to track the target using the 1S13, allowing the system to engage higher altitude targets.

The downside is that this will produce a track warning to a RWR that will potentially come significantly before the system can engage.

Edited February 23, 2022 by Northstar98

[Ironhand]

4 hours ago, Northstar98 said:

I doubt it, the 2 RADARs operate on different bands; the 1S11 acuisition RADAR operates in the C-band (0.5 - 1 GHz), and the 1S13 target-tracking & fire-control RADAR operates in the I-band (8 - 10 GHz) [1].

Yes. I knew they operated in different bands but there’s some logical reason for the limitation. Just wondering what it is.

[Northstar98]

On 2/18/2022 at 8:20 PM, Ironhand said:

Yes. I knew they operated in different bands but there’s some logical reason for the limitation. Just wondering what it is.

I explained it in the post - it seems to be a physical limitation of the antenna itself.

The antenna produces a beam that only covers 20° in elevation (actualy stacked beams, but minor trivialities - still covering the same elevation), at the quoted maximum engagement ranges, the maximum altitude targets can be at while still falling within the beam (and thus be detected by the 1S11) matches the numbers pretty well (though I assumed the lower edge was at 0° elevation, if it's slightly below that, then that would explain any discrepancy).

What I don't get is that the RADAR can detect targets at higher altitudes than the maximum engagement altitude, they just have to be beyond the maximum engagement range (and the further away they are, the higher the maximum altitude), theoretically they could be tracked by the 1S13, allowing them to be engaged at higher altitudes once they fall within maximum engagement range.  

Edited February 22, 2022 by Northstar98

[Ahmed]

Exactly what he says. The only catch here is that DCS models a hard altitude and not an elevation angle (not to mention that it also limited to a single radar per unit, so can't model the 1S11 and 1S31 in the Straight Flush vehicle).

Currently in DCS the max 7km altitude is set in the missile definition. So, some room for improvement here to be able to simulate a full strength SA-6 battery at some point.