As I recall most radars have a dedicated section on the main radar with its seperate guidance portion for the missile guidance function. Using the main beam was sort of the norm for SARH missiles which homed in on the reflected energy from the main beam. Todays active units have their own datalinks & hence dont follow the same guidance options (its a choice).

The S-400’s Big Bird is S-Band, the FCR is X-Band.

Its in the IAFs best interest to buy a few Nebo-M sets for the north east against PRC in particular, but I suspect it all comes down to affordability & IAF would rather for L-Band Phalcons. Though Nebo-M has a VHF band AESA as well..

This would be your dream come true i guess in terms of frequency diversity. The US has its own advances in UHF.

India plans to acquire 5 S-400 batteries. Wonder if they are all up units with such ssytems or merely the plain ones with the regular fit.

Radar burn through ranges & datalink ranges don’t need to be paired. You can drive them differently through different Transmit/Recieve chains. Plus burnthorugh would really matter against noise jamming. Against deception & other methods, best to rely on equal sophistication on your side. If you deploy noise jammers then they best be disposable since they will be easier to track and target.

Agree with you that the 2084 does seem to be ok for its class. India also chose a derivative of the Thales system – a S Band MFCR for its local BMD.
http://www.globalsecurity.org/wmd/world/india/images/bmd-image2.jpg

The MFCR is pretty much in the same class & performance as the 2084.
Makes me think – that the IAF will likely test the MRSAM against TBM targets too. While not purpose designed for the task any capability would be a plus. The baseline architecture should be able to support it.

I am sort of surprised the MFCR for MEADS is X-Band. India is going the same way (I suspect) with a SHORAD radar & while X-Band has notable advantages (resolution, compactness hence its evergreen suitability for FCRs), I do wonder whether making things easier for the EW guys is warranted.

What I meant was if multiple folks are acquiring the radar for BMD missions & the max range is well in line with much larger systems (470km max against presumably large airbreathing targets), it can work against low RCS targets and should be able to acquire them at reasonable ranges. Regarding maturity, you have a good point there, however, if the performance was lagging range wise against emerging low RCS threats, i suspect few would have taken it.
Regarding guidance, the MRSAM has its datalinks in the C3I van, not the radars, so as long as the surveillance radars are precise enough to guide it into the kill box for its x band seeker it should be enough. However, the issue becomes harder for the true wideband LO threats. Older gen radars netted into the IAF IACCS (C3I network) or the MRSAM guidance may simply not be precise enough to guide the missile all the way in, and the onboard seeker may be able to lock on at only reduced ranges. Of course, all this is hypothetical since the IAF (like other professional AF) tends to be very methodical & for all I know, they took all these issues into account already.

Israel notes dozens of MMRs have been sold mostly for the air surveillance & S/BMD mission.
That to my mind indicates its capable against low RCS targets.

The fact its still in production wherein GaN radars are being increasingly hawked – the Giraffe as you mention, comes to mind as an ITAR free option, indicates that it is all said and done a capable system. Not as much so as the S-400 with all options (eg the VHF/L-Band AESAs for multi-band tracking)

I don’t think India (yet) faces true wideband stealth opposition – I’d rate even the JSF higher than the J-20 in that, because shaping apart, the US has a decades ++ lead over the ROW in VLO/LO development & the funding & MIC to deliver on that. There is stuff the US knows, which the rest of the world is still developing.

For true VLO threats, I think the only options (for a simpler fix) are either to dramatically increase power/range in the low bands (L/VHF/UHF), i.e. GaN. Or better still develop some sort of multi-static system. One emitter & multiple receivers, coupled with the above.

Can the MRSAM deliver against a LO threat like the J-20? I do suspect the IAF would not have agreed to the program unless it was future capable (to a degree), using for instance feeds from multiple radars (not true multi-static as mentioned above) but somewhat of an approximation. The missiles would have to be guided in to a higher degree by the C3I van than a regular target.

So not true fire & forget.

Its not merely range, band and power aperture functions though, but also algorithms & also receiver performance and also the design of the waveform itself.

Elta might have had breakthroughs there in terms of detecting low RCS targets and then deploying that on various radars.

http://www.freerepublic.com/focus/f-news/1970095/posts

The CAEW is believed to be the first radar to use a technology known as “track before detect” (TBD). Discussed since the 1970s, TBD improves the ability of a radar to detect small targets. To eliminate false alarms, conventional radars have to set a clutter and noise threshold below which radar returns are ignored. In TBD, those returns are assembled into the equivalent of a God’s-eye picture and scanned for patterns that resemble target tracks.

CAEW uses TBD to improve detection of small targets and reduce false alarms, without a large antenna or high power levels. The technique is also valuable in helping an AESA detect and track stealthy targets. Once TBD has indicated the location of a possible target, the AESA focuses more power on that area.