I love these arguments.
Not one iota of information on the public domain on how these systems would fare against each other… But one and a half pages and we are already on industrial fisheries!
Can we stop the thread? There’s no available information in order to make any meaningful insight. The end.
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:rolleyes:

https://twitter.com/US_Stratcom/status/1160218017957068800

for what its worth…

Thanks! That case study gives good insight into the tools parameters.
I think we can be confident that the Gamma-DE has 3D beam forming capabilities to allow for sector-scan, starring mode, especially for ABM purpose (PESA 91N6E has it too by now). Observation modes are mentioned in the spec sheet further below. In that case the azimuth angle should be increased to >90°, right?
I would also like to know what would make sense for the “Fraction of time to search target” parameter. A portion of the aperture should be allocated to track beam functions, so what % parameter would make sense in this case? This is a main driving parameter which has dramatic impact on the results.
Another thing concerning the Gamma-DE is that photos without shroud show 560 elements at the 1 of 2 sub arrays. Based on this and your sub-tool for element count – frequency, I get 820 mhz. The paper says 1024 elements however, so could the rest be side-lobe cancelling elements or reserve ones?

Pulsewidth can be estimated from the range resolution which known to be 300 meters. Technical paper (which i would link below) about Gamma DE mentions compression ratio in excess of 100. Finding how much however is difficult. One way i sought is looking at AN/TPS-59 Radar as it seems Gamma DE have similar parameters.

The Pulsewidth is then can be “guessed” to be 1000 ms with 0.18 KHz (180 Hz) PRF. For 18% Duty cycle. The pulse compression ratio would then be 500 which appears reasonable with LFM (Linear Frequency Modulation) The LFM apparently the only pulse compression method where target velocity is not limited (Others like Polyphase etc are doppler sensitive and can only be used for target in Subsonic speed or less). The higher PRF and shorter pulsewidth could be exist too mainly to compensate for short range target detection. Transmitting at long pulsewidth and pulse compression solves resolution BUT not the minimum range.

So basically you selected the lower PRF number from the similar AN/TPS-59 to optimize the results for max. range – RCS performance. Pulsewidth came via duty cycle. But without that, what could we extract from the 300m range resolution and compression ratio of 100?

I would also like to know how much general practice those 20-40% safety reserves are? How do western and eastern radar schools handle this? Isn’t it redundant due to probability of detection parameter (just use e.g 95% to cover that margin)?
Fortunately you directly found the TRM power levels for this case, so we have become aware that there seems to be a 40% safety margin. Without that information, by using the tool to extract it, we would have got the wrong numbers.

The smaller 0.13 Sqm Yield range of about 301 Km or about 16% more than what is available in the export literature for the radar. This case would show overestimate of the sheet which might result from the limitation of the scenario (sector scan mode)

301km for a 0,13m² target would represent a 16% safety margin, yes. I wonder whether we can use that 250km number as fix point to vary unknown key performance parameters such as “Fraction of time to search target”.

This is a Technical paper by I.Immoreev regarding the design and development of Soviet/Russia ground based AESA. It contain good information on design and considerations about Gamma-DE Radar.

https://id.scribd.com/document/41526…Antenna-Arrays

Thanks that was quite interesting. I wonder if the Gamma-S series uses that new (back in th mid 2000’s) TRM technology mentioned, with 200W instead of Gamma-DE’s 55W and where they are now with the S-band AESA for Nebo-M and beyond.

The presentation of this deep upgrade as “new fighter” was a PR stunt.

Its the same Azarakhsh/Saeghe project of reverse engineering the F-5, but they have now reached a level of indigenous component production that it can be called “fully homemade”.

Its not the original F-5 anymore, the whole avionics has been modernized.

– Grifo radar copy with GMTI and SAR mode

– INS/GPS + TACAN navigation suite

– Modern HUD + MFDs with digital map

– Modern IFF, RWR, altimeter etc.

all on MIL-STD-1553 bus.

Full hydraulics and actuator suite

Plus a new ejection seat and J-85 small turbojet copy.

Previously they mainly had mastered the airframe, but could not do a serial production due to the lack of those critical subsystems.

Those interested can see the details in the video or this instagram site: https://www.instagram.com/iranian_defensive_power/

In total nothing fancy, but guys from the industry know what it takes to build all that from zero. The only OEM that would supply components to Iran is China… So kicking it off without foreign OEMs requires much effort.

@Austin

I discuss the number rpgtype7v posted here. I have serious doubts whether a 8-10 ton 11000km range single warhead ICBM could be possible but in light of a HGV like the Avantgard, my questions have arised.

A 8-10ton single warhead nuclear ICBM would be impressive. The Rubezh is now on hold.

HGV’s tested previously fly 2/3 of the range as normal ballistic missiles, with a range increase of about 20%. From the animation on the Avantgard we can see a almost non-ballistic HGV optimized flat trajectory.
I wonder if a 10 ton Rubezh which would have a range of 5500km on a ballistic trajectory would be able to reach a credible 8000-10000km ICBM range with an advanced HGV like the Avantgard. Heat management, continuous power supply for control surface actuators are all problems that would need to be solved if the Avantgard would fly a flat trajectory at ~150km altitude.

Another point is: Avantgard on Sarmat ICBM would normally have a higher release speed after boost phase that would make a much improved heat shield necessary compared to the lower velocity Rubezh.
So either the Avantgard on Sarmat is much improved regarding the heat shield or the Avantgard load is of a quantity/weight that slows it down to Rubezh burnout speed at release.

What makes me wonder is whether it would be possible to achieve 10000km range with a flat trajectory HGV, whereas a pure ballistic system would only do 5500km (Rubezh). Means transforming energy to create lift primary instead of transforming speed into heat as in conventional reentry vehicles. But would a range increase of up to 100% be possible?

Mig-31 + F-18

Altough unlikely to have been sold in that combo.

@swerve

Erieye-ER (one customer so far) has S-band GaN modules. I think the Erieye antenna is 8 x 0.6 metres, so about the same as your 2×2 metres. Dunno how many modules, though, or what power.

The GaN modules are said to give a massive increase in detection range of VLO objects. Maximum range against big, high RCS things such as ships is still the horizon.

I still have doubts about the high performance calculated by stealthflankers spreadsheet but if there is no mistake, it now makes perfect sense why some countries like Sweden go for S-band. Its not only economical but would have a high capability against LO up to VLO assets.
SiC, silicon and GaA are all able to provide a 50W peak power per element, no strict need for advanced and expensive GaN modules.

If there is no tight space restriction, a 6000 element array with low cost 50W elements provides the same range performance as a 3000 element, state of the art GaN 400W array.
Thanks to stealthflankers sheet, this now becomes visible. As well as the extreme performance even lower power 50W non-GaN S-band TRMs can develop, exceeding line of sight endo-atmospheric range against any conventional target and providing stand-off EW range counter-VLO capability or/and burn-trough capability in heavy jammed environment.

It now also makes sense why Russians skipped the Gamma-D radar and went for the Gamma-S, as its high power is sufficient to compensate better counter-VLO performance of L-band. On the other hand, you can’t achieve power levels of 50W without more expensive GaN modules in higher bands such a X-.

But I still don’t know if PW of 100µs and PRF of 2khz would be applicable for such early warning radars as those data are only derived from that TRM datasheet I posted. I still would like to know what PRF and PW levels are common for VHF- to X-band radars in search mode or illumination.

Okay, so is it the maturity of advanced S-band silicon T/R modules that has created such high range performances?

The effects you mentioned should create negligible range performance penalty, am I right?

As a example: Such a S-band AESA in form of a ground based system like the Ground Master or an airborne AESA AWACS would have following performances with ~4000 modules:

50% Pd volume search: 300km against a -40dbsm target and that in 10cm S-band where RAM and RAS should be much lower performing. Means if we are generous and give a -10dbms RAM/RAS performance in S-band, its range performance would be in fact 300km against an effectively -30dbsm target (0,001m² RCS, shape only). That would be a typical long range EW radar range performance against almost any known stealth fighter target.

I’m somewhat skeptical about those figures. Maybe those pulse width and max. PRF values from the T/R module data sheet are for some reason not applicable?