Indian AESA Radar Developments

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Thoughts About the New Uttam AESA RADAR- MK1A (and some other stuff)​

May 31, 2021
So, defense nuts recently nicked pics of a new variant (same but different) of Uttam Active Phased Array Radar. The tender was unusually information-rich (for a critical piece of technology slated to equip a combat aircraft). In case, that wasn't enough, LRDE proceeded to publish a screenshot of an MFD displaying tracking information. In the screenshots, Uttam appears to be keeping a 'FOX3-worthy' lock at a Tejas well beyond 140 kilometers and that's really something. Tejas easily has the lowest radar signature (for a non-stealth combat aircraft) in its class. Air-to-Air mode is where Uttam has exceeded expectations. It also has advanced NCTR and imaging capabilities.



Another thing, there is a misconception that Uttam's operating power is 3.6KW,_ okay, no, it's not. It's actually the heat dissipated during the operation or in other words - its liquid circulation has to remove 3.6 KW of heat out of the array. The actual radiating power is several times the heat dissipated. There are roughly 736 TRMs on the radar. To be accurate, it's actually the overall heat dissipation by the AAAU, the Receiver Exciter Processor (REP), and LRU. However, it appears to have been replaced by a more efficient cooling system as LRDE has been able to increase the number of TRMs to 992. For comparison, APG-80 that equips F-16B60 has ~1020 TRMs. Mind you though, the AAAU of Uttam is smaller than its PESA predecessor, the hybrid MMR (~600mm compared to 650mm of the PESA <MMR). An increased number of TRMs also means that it would be able to track a greater number of targets, it can already track 94 targets simultaneously.

Uttam uses good ol' dipoles as radiating elements, Not exactly what you expect from a radar designed in the late 2010s. Most of the contemporary radars are using Tapered Slot Antenna (TSA), e.g. RBE-2A on Rafale, ES-05 on Gripen-NG. That might prove to be a bottleneck in the radar performance, and it shows up as relatively narrow bandwidth - just 1 GHz. It's still a step up from N-011M BARS' 600 MHz but quite dismal compared to ~3 GHz bandwidth displayed by some of its contemporaries (APG-79, RBE-2A, etc). It's not like LRDE doesn't have the capability to developed UWB arrays. We have already seen VAAAU-16/32 in EW systems with over 4 GHz of operational bandwidth. Uttam's AAAU will need replacing if it is to keep up with the ever-evolving ECM environment.



Back to LRDE's habit of oversharing- They literally published almost every spec of their S-band TRM used in Arudhra 4D radar. I mean, guys, we know you made the radar. Take it easy. We just want better pics of the radars, not their specs or a blow-by-blow account of how you developed "something" in a journal.

While we are at other radars- there is something people confuse about- the L-STAR radar of Netra- There were two L-STAR radars, one from CABS and the other from LRDE. The range figure that is thrown around in the public domain is of the LRDE variant which is not what Netra currently has. LRDE lost to CABS design. In any case, CABS L-STAR is slightly larger than Saab's Erieye in terms of physical dimensions (8.2m vs 8m in length, Global Eye has a larger antenna). In test flights, Netra was able to track targets at 475km distance when operating in the extended-range mode. The tracks are likely to be airliners, even so, unlocking the true potential of the radar is one of the perks of having an indigenous design. The same goes for Uttam, looking forward to seeing what those "proprietary radar modes" developed by LRDE can do.

 

Thoughts About the New Uttam AESA RADAR- MK1A (and some other stuff)​

May 31, 2021
So, defense nuts recently nicked pics of a new variant (same but different) of Uttam Active Phased Array Radar. The tender was unusually information-rich (for a critical piece of technology slated to equip a combat aircraft). In case, that wasn't enough, LRDE proceeded to publish a screenshot of an MFD displaying tracking information. In the screenshots, Uttam appears to be keeping a 'FOX3-worthy' lock at a Tejas well beyond 140 kilometers and that's really something. Tejas easily has the lowest radar signature (for a non-stealth combat aircraft) in its class. Air-to-Air mode is where Uttam has exceeded expectations. It also has advanced NCTR and imaging capabilities.



Another thing, there is a misconception that Uttam's operating power is 3.6KW,_ okay, no, it's not. It's actually the heat dissipated during the operation or in other words - its liquid circulation has to remove 3.6 KW of heat out of the array. The actual radiating power is several times the heat dissipated. There are roughly 736 TRMs on the radar. To be accurate, it's actually the overall heat dissipation by the AAAU, the Receiver Exciter Processor (REP), and LRU. However, it appears to have been replaced by a more efficient cooling system as LRDE has been able to increase the number of TRMs to 992. For comparison, APG-80 that equips F-16B60 has ~1020 TRMs. Mind you though, the AAAU of Uttam is smaller than its PESA predecessor, the hybrid MMR (~600mm compared to 650mm of the PESA <MMR). An increased number of TRMs also means that it would be able to track a greater number of targets, it can already track 94 targets simultaneously.

Uttam uses good ol' dipoles as radiating elements, Not exactly what you expect from a radar designed in the late 2010s. Most of the contemporary radars are using Tapered Slot Antenna (TSA), e.g. RBE-2A on Rafale, ES-05 on Gripen-NG. That might prove to be a bottleneck in the radar performance, and it shows up as relatively narrow bandwidth - just 1 GHz. It's still a step up from N-011M BARS' 600 MHz but quite dismal compared to ~3 GHz bandwidth displayed by some of its contemporaries (APG-79, RBE-2A, etc). It's not like LRDE doesn't have the capability to developed UWB arrays. We have already seen VAAAU-16/32 in EW systems with over 4 GHz of operational bandwidth. Uttam's AAAU will need replacing if it is to keep up with the ever-evolving ECM environment.



Back to LRDE's habit of oversharing- They literally published almost every spec of their S-band TRM used in Arudhra 4D radar. I mean, guys, we know you made the radar. Take it easy. We just want better pics of the radars, not their specs or a blow-by-blow account of how you developed "something" in a journal.

While we are at other radars- there is something people confuse about- the L-STAR radar of Netra- There were two L-STAR radars, one from CABS and the other from LRDE. The range figure that is thrown around in the public domain is of the LRDE variant which is not what Netra currently has. LRDE lost to CABS design. In any case, CABS L-STAR is slightly larger than Saab's Erieye in terms of physical dimensions (8.2m vs 8m in length, Global Eye has a larger antenna). In test flights, Netra was able to track targets at 475km distance when operating in the extended-range mode. The tracks are likely to be airliners, even so, unlocking the true potential of the radar is one of the perks of having an indigenous design. The same goes for Uttam, looking forward to seeing what those "proprietary radar modes" developed by LRDE can do.

So Uttam is a gen behind modern aesa radars. Well that doesn't sound reassuring...Also gripen has an RCS of 0.1 so Uttam would be fine against the Pakistanis still questionable against the Chinese..
 
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So Uttam is a gen behind modern aesa radars. Well that doesn't sound reassuring...Also gripen has an RCS of 0.1 so Uttam would be fine against the Pakistanis still questionable against the Chinese..
It seems so. But it’ll be better than anything we have right now except Rafale and EL/M 2052. And AAAU can be upgraded when TSA or other type of TRMs supporting broader bandwidth will be fully refined by LRDE/ CAB as I believe that radar are like phones with hardware and software. Ours are with older hardware
 
It seems so. But it’ll be better than anything we have right now except Rafale and EL/M 2052. And AAAU can be upgraded when TSA or other type of TRMs supporting broader bandwidth will be fully refined by LRDE/ CAB as I believe that radar are like phones with hardware and software. Ours are with older hardware
I have read on other sources that Uttam is superior to the 2052. Since it's the base from Uttam was inspired/created/ripped off. So maybe what is displayed us actually an older version and the Uttam that will be used on Tejas will have Vivaldi. Also we are also manufacturing rbe2 trms so I highly doubt we are not capable of making Uttam with Vivaldi..
 
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I have read on other sources that Uttam is superior to the 2052. Since it's the base from Uttam was inspired/created/ripped off. So maybe what is displayed us actually an older version and the Uttam that will be used on Tejas will have Vivaldi. Also we are also manufacturing rbe2 trms so I highly doubt we are not capable of making Uttam with Vivaldi..
It’s very much possible considering that RADAR Capability is one of the most guarded secrets in a fighter jet and no one in their right mind will tell their actual capability. All radar companies mostly show guesstimates or performance of the previous gen product in most cases.
Also lately their is lots of noise about Vivaldi type of TRM development and RADAR development as a whole by LRDE/DRDO and CABs.

But I doubt it’ll be better than what the most advanced product the ELTA have right now. It’s also possible that the product (Export version of 2052) is too old for their own standards
 
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It’s very much possible considering that RADAR Capability is one of the most guarded secrets in a fighter jet and no one in their right mind will tell their actual capability. All radar companies mostly show guesstimates or performance of the previous gen product in most cases.
Also lately their is lots of noise about Vivaldi type of TRM development and RADAR development as a whole by LRDE/DRDO and CABs.

But I doubt it’ll be better than what the most advanced product the ELTA have right now. It’s also possible that the product (Export version of 2052) is too old for their own standards
Elta 2052 is actually pretty average it's on par with apg 63v2 levels and since the Israelis never really replaced them I doubt it's that advanced. But we have basically no info on the elm 2052 itself so it's just speculation..