A quick analysis of MTNs photos
So now the names for each of the Bavars radars are mentioned. Hence let me further explain what I think about the Bavars radar systems as I did before i this thread.
One of the Bavar battery radars is called engagement radar and the other accusation and engagement radar. Both work in the same bandwidth, both are phased arrays and as said earlier apparently active ones. So why using two such radars in the Bavar battery and not just one like in the S-300PM/400, Patriot and all the others?
I speculate that the reason is that the Bavar has a higher emphasis to work effectively against VLO, stealth targets while using SARH guided long range SAMs.
If you want to use a long range SARH guided missile against a stealth target at max. range you will have a hard time to track the target at those ranges in S- to X-band for which their VLO features are best optimized. It will even have a hard time to detect the target.
A somewhat complex but feasible solution is the following one which fits the Bavars displayed systems exactly.
Long range surveillance radar data is used as the highest tier source of information this can be by large static systems such as the IRGC's Ghadir or the IRIADF OTH radar which is in development or already operational. This is passed down to lower tier long range surveillance systems such as the Meraj-4, Matla ol Fajr-3 or Nebo-SVU.
Iran has no own mobile Nebo-SVU equivalent, a mobile VHF AESA with space time processing, digital beamforming and most importantly for our case sufficiently accurate 3D coordinate information. But with the static Fath-14 we know that they are working on what would become a Nebo-SVU equivalent.
High tier system such as Ghadir/OTH radars can only do early warning of the rough area where the target should be. The first system of the greater Bavar system which could detect a stealth target is successfully would be a Nevo-SVU like system, potentially using its AESA beamforming capability to search in a limited portion of the airspace with greater concentration of RF energy to archive greater dynamic range. The features of the Nebo-SVU I described above made it the first VHF-band radar with accurate enough resolution to successfully guide a SARH SAM towards it with a good chance for the SAM seeker to pick up the target a terminal phase. This theoretical operation was made famous by Carlo Kopp for Australian Airpower for the S-300PM/400.
Now lets come back to those two Iranian Bavar battery radars:
One is a apparently a AESA wich is enough for following tasks: 360° conventional radar search, sector search using electronic scanning, digital beamforming to track and illuminate a target (needs to be CW/FMCW), track the missile if necessary and create a datalink beam to provide guidance updates to the SAM (if sufficiently advanced). The general functions described are also performed by the S-300/400s Tombstone/Gravestone radars and thus in theory this single radar would be sufficient for the Bavar battery operation. Because its called engagement radar we should expect a CW(FMCW illumination capability.
The other dedicated engagement radar has no search function, is apparently a AESA too and have digital beamforming capability to concentrate CW/FMCW illumination in a smaller portion of the airspace than PESAs such as the engagement radars of S-300/400 and Patriot. This feature would give it probably a similar illumination intensity at the target as the S-300/400 while operating at a much lower emitting power as well as smaller aperture size.
To put this together I think there is a special mode of operation which is used against stealth targets or targets very far away: A Nebo-SVU like radar has detected a stealth target at extended ranges such as 250km using beamforming as described above to archive better range (by knowing the rough portion of airspace where the target should be by higher tier early warning systems).
This information is passed to a Bavar battery. The SAM is launched with those coordinates feed into its INS. The search and engagment radar of the Bavar starts to sporadically emitting in order to track the SAMs position and feed it with guidance updates via a dedicated data-link beam produced by the beamformer. At this point this Bavar radar does not see the stealth target, it only uses the coordinated provided to it by the Nebo-SVU-like radar.
Coming closer terminal range the dedicated engagement/illumination radar is activated to illuminate the portion of airspace where the Nebo-SVU-like radar tracks the target. Also this radar sees no target and tracks nothing.
Of course at one point the SAM get close enough to the target to pick up the RF energy reflected by the target and the inaccuracy coordinate info provided by the Nebo-SVU-like system is no longer necessary. A SAGG/TVM like terminal SARH guidance kicks in, does the necessary trajectory corrections and possibly sends back what its seeker detects via data-link to do cross-processing with the information provided by the Nebo-SVU-like or other sensors.
Hence at the moment I think the Bavars search and engagement radar is the main battery radar used for large targets and at lower ranges than the max. SAM range (possibly for use with lower range SAMs of the Bavar), it also a secondary search function is necessary.
The dedicated engagement radar is a illumination radar possibly not even possessing receiving capabilities. A illumination radar with no receiving system would be a bad decision for system redundancy but could be a wise one for cost effectiveness and knowing that against stealth and very distance targets no tracking would be possible anyway.
This is my explanation for this unusual arrangement of two such radars. It would make a lot sense for a system designed against stealthy opponents or designed for very long range engagement.
A few notes: The engagement-only radar would certainly have a receive function for tracking, for redundancy purposes its "a must", its provides the battery with the capability to to remain operational even if one of the two battery engagement radars has been killed.
The Meraj-4 takes the place of the Big Bird in the S-300/400, a large ~6000 element PESA S-Band search radar (but its anti-stealth capability could be reduced compared to the Big Bird due to the higher frequency).
The Najam 802 is not proven to be related to the Bavar, but compared to the larger Meraj-4 it is apparently a AESA system with beam forming and more sophisticated capabilities (foremost beam concentration to get a track of a distend/stealth target). It resembles the Russian Gamma-S which s also part of the Nebo-M multiband system.