Looks like a VHF phase array to me.
Yes it is, Niobium SV is phased array. It's about quarter to half performance of larger RLM-M or Nebo-SVU. Still, NIobium is more compact apparently.
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Also. I just cant miss the Shoigu's visit to bomb plant, where the plant head apparently claim to make Glide version of the FAB's being made there. This is FAB-1500-2600T
So lemme present you. What if FAB-1500 glide kit.
Folded condition for storage in Tu-22M3 internal bay. Maybe 2 of them can be carried at a time.
The deployed kit.
I cant give aerodynamic etc... but the logic is that the bomb will have aerospike, and canard control. The aerospike will reduce the drag of the baseline bomb hopefully without disrupting the stabilizing effect from the bomb's ballistic ring. Most of the lift will be provided by the wings.
The release aircraft would be a Tu-22M3, flying and release the bomb at 10000-12000 meters at speed of Mach .75 or high subsonic which apparently the limit for the M-54 bomb family. The rest would lies on how much L/D ratio the configuration can provide. IF it can reach value of 5 It will have 50-60 Km range. Defeating Medium-range system such as Buk, NASAMS and Iris-T ground based. But still within the envelope of S-300PT/PS and Patriot if arrived.
Any less L/D than 5 will endanger the carrier platform or only defeat short range systems. My Russian collegue already called this a meme but.. I'm sorry i just cant let Shoigu's visit passed by.
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I also take liberty to do some RCS estimates. the baseline FAB-1500-2600T, the bomb is assumed and i think a realistic one PEC. The modeling is at 35 frequencies spanning from VHF down to mmwave (0.15-35 GHz)
As usual the RCS are presented in Median format.
Median wise, despite the Bomb's ballistic ring being strong contributor, it's still relatively small in order of 0.5-0.1 sqm across the frequencies being considered in estimation.
The modeling for the one with Glide kit is in next post as there is limitation on number of images i can put in one.