D-Scythe Posted March 1, 2008 Posted March 1, 2008 Hi! 21kW high performance man.steered-PESA combo radar (Irbis-E) with 240° FOV (yes, two-four-zero) and latest IRST (OLS-35; 180°FOV) and with glass cockpit, and other funny things. 240 degrees isn't a huge deal - it just means that the ESA is mounted on a mechanically steerable plate. The radar will still be unable to cover a target at its 8 o'clock and 4 o'clock simultaneously, as AFAIK is still limited to a 120 degree sector just like other comparable fighter radars.
Alfa Posted March 2, 2008 Posted March 2, 2008 So the new one still doesn't have AESA? No the "Irbis" is a PESA of similar design to the "Bars" installed in the Su-30MKI operated by India. Do any Russia planes have AESA? Yes the MiG-35 does - the "Zhuk-AE": JJ
Alfa Posted March 2, 2008 Posted March 2, 2008 240 degrees isn't a huge deal - it just means that the ESA is mounted on a mechanically steerable plate. The radar will still be unable to cover a target at its 8 o'clock and 4 o'clock simultaneously, as AFAIK is still limited to a 120 degree sector just like other comparable fighter radars. Yes but the ability to scan such a wide area is nevertheless a great advantage for an interceptor - you need to find an opponent before you can engage it :) . Moreover, you can do a lot of evasive manouvering without loosing track of your target. An AESA is able to devide its beam between two or more targets at adverse angles, but this also means dividing the output power between them - just as the fixed nature of its antenna means a more narrow search sector. JJ
D-Scythe Posted March 2, 2008 Posted March 2, 2008 Yes but the ability to scan such a wide area is nevertheless a great advantage for an interceptor - you need to find an opponent before you can engage it :) . Moreover, you can do a lot of evasive manouvering without loosing track of your target. If you're stuck with PESA, then yes, that's about the best it gets. With AESA though, you can always mount a bunch of extra arrays...anywhere in the aircraft. Thus allowing tracking of 2 targets simultaneously 240 degrees apart. An AESA is able to devide its beam between two or more targets at adverse angles, but this also means dividing the output power between them... Only a few T/R modules would be directed at a target at any one time, so even if there was one target, the output power would be minimal anyway. This is actually an advantage. just as the fixed nature of its antenna means a more narrow search sector. More narrow than a 240 degree search sector, but arguably being able to send dozens of radar beams instantaneously to any point in a 120 degree search sector is nothing to scoff at.
Mugatu Posted March 2, 2008 Posted March 2, 2008 You mean time slice, it doesn't divide the beam. Yes but the ability to scan such a wide area is nevertheless a great advantage for an interceptor - you need to find an opponent before you can engage it :) . Moreover, you can do a lot of evasive manouvering without loosing track of your target. An AESA is able to devide its beam between two or more targets at adverse angles, but this also means dividing the output power between them - just as the fixed nature of its antenna means a more narrow search sector.
p_o_d_2_2 Posted March 2, 2008 Posted March 2, 2008 Yes the MiG-35 does - the "Zhuk-AE": Is there a particular reason why the Su-35 wouldn't be fitted with the same radar if it has to compete in an export market with planes like the Super Hornet that have AESA?
DarkWanderer Posted March 2, 2008 Posted March 2, 2008 Only a few T/R modules would be directed at a target at any one time An AESA is able to devide its beam between two or more targets at adverse angles Wrong understanding of the principle. AESA array does not mean 10000+ mini-radars, it's one radar with many emitters that gives the ability to redirect the beam electronically - without turning the antenna. So, roughly, it just can track any number of targets (limited by processing equipment) inside the cone of 120 degrees. Something like TWS, but with about 10^3 passes per second. 1 You want the best? Here i am...
Pilotasso Posted March 2, 2008 Posted March 2, 2008 The antenna shifs from target to target so fast you can almost consider it uses multiple lock beams silmultaneously. .
D-Scythe Posted March 2, 2008 Posted March 2, 2008 Wrong understanding of the principle. AESA array does not mean 10000+ mini-radars, it's one radar with many emitters that gives the ability to redirect the beam electronically - without turning the antenna. A radar with an AESA antennae can generate multiple beams, AFAIK.
tflash Posted March 2, 2008 Posted March 2, 2008 Indeed, it is NOT time-sharing (although of course this technique will also be used, but the whole idea is that you can form many beams by combining emmitter nodes. It does have an impact on directed output power, however. The more you are tracking, the less energy available in your signal. Just one of the many, many design issues involved in this incredibly sophisticated technology. As it is now, it has a certain maturity in big AESA radar systems on surface combatant ships, but for airborne systems on fighters not everything is perfectly ironed out. I guess US is way ahead of the pack with its APG-77 and APG-79. [sIGPIC][/sIGPIC]
D-Scythe Posted March 2, 2008 Posted March 2, 2008 It does have an impact on directed output power, however. The more you are tracking, the less energy available in your signal. Just one of the many, many design issues involved in this incredibly sophisticated technology. And again, this isn't necessarily undesirable.
tflash Posted March 2, 2008 Posted March 2, 2008 Well, it could be used in an EMCON setting. No need to alert the bogeys at great range that you are tracking them. [sIGPIC][/sIGPIC]
EricJ Posted March 3, 2008 Posted March 3, 2008 Is there a particular reason why the Su-35 wouldn't be fitted with the same radar if it has to compete in an export market with planes like the Super Hornet that have AESA? By checking the Boeing and other related sites, AESA so far has been used by VFA-213 for testing AFAIK not in the US Navy active combat squadrons yet. Yes VFA-213 is an active squadron but they've been tasked with playing with the new toys... But realistically if the SH did get the AESA for export? who knows how it would compete.... Also, the AESA tested on a Super Hornet allowed it to do a multiple target engagement with JDAMs... so it's not just for AAMs it's useful for, and quite frankly multiple targeting of GPS guided bombs just scares me, so if a country does get AESA, they can do this, provided they get JDAMs as well, and so far it's not likely but then again, the Aussies would more than likely want and get them. http://www.boeing.com/defense-space/military/fa18ef/news/2006/q2/060418b_nr.html Back on topic though.... it's a shame that they dropped the canards, it looked more lethal that way.... Homepage | Discord | My Files | YouTube 'Nearly everyone felt the need to express their views on all wars to me, starting with mine. I found myself thinking, “I ate the crap sandwich, you didn’t, so please don’t tell me how it tastes.”' - CPT Cole, US Army
p_o_d_2_2 Posted March 3, 2008 Posted March 3, 2008 By checking the Boeing and other related sites, AESA so far has been used by VFA-213 for testing AFAIK not in the US Navy active combat squadrons yet. Yes VFA-213 is an active squadron but they've been tasked with playing with the new toys... But realistically if the SH did get the AESA for export? who knows how it would compete.... Isn't Boeing offering Super Hornets with AESA to India?
Alfa Posted March 3, 2008 Posted March 3, 2008 Is there a particular reason why the Su-35 wouldn't be fitted with the same radar if it has to compete in an export market with planes like the Super Hornet that have AESA? One reason could be that Sukhoi traditionally got their radars from NIIP - N001 "Miech", N011M "Bars" and now "Irbis", while MiG got theirs from NIIR(N019 "Rubin" and "Zhuk-M" for the MiG-29). A couple of exceptions to this though are the MiG-31(NIIP's "Zaslon") and the Su-27KUB which was fitted first with the "Zhuk-MS"(slotted array) and later the "Zhuk-MSF"(PESA) both from NIIR. AFAIK NIIP does not yet have a functional AESA set ready, but I believe they are working on one - in fact the one intended for the 5th gen. fighter under development("PAK-FA" project). I am not sure that this new Su-35 variant is intended to compete on export markets(although I am sure it will be offered), but rather is meant as a "stop-gap" measure for the Russian airforce itself - in which case it would make little sense to wait for a radar that likely won't be ready before the new 5th gen. fighter is nearing production stage. Anyway, I have been reading up a little on this new "Irbis" radar, which basically can be described as a "super Bars". It has a 900 mm PESA antenna mounted on a new two-stage electro-hydraulic drive(providing the wide scan area mentioned earlier) and an insanely powerful transmitter with a peak output of 20Kw(!) and average of 5 Kw - NIIP claims head-on detection ranges of 350-400 km against "fighter sized" target of RCS=3m2 and up to 90 km against a "stealth target" of RCS=0,01m2. The radar can track up to 30 targets and simultaneously engage 8 with ARH missiles or 2 with SARH missiles. JJ
Alfa Posted March 3, 2008 Posted March 3, 2008 Also, the AESA tested on a Super Hornet allowed it to do a multiple target engagement with JDAMs... Yes and they claim that the radar could even have been guiding AAMs against aerial targets at the same time(!). JJ
Alfa Posted March 3, 2008 Posted March 3, 2008 Isn't Boeing offering Super Hornets with AESA to India? Yes I believe they are - which in turn could have something to do with MiG now offering the MiG-35 with AESA instead of initial MiG-29M2(with Zhuk-M slotted array) for the same tender. JJ
EricJ Posted March 3, 2008 Posted March 3, 2008 Isn't Boeing offering Super Hornets with AESA to India? I doubt it, least not yet anyways. Like the Russians, the US will send out a degraded version (or in this case the older Block I radar)... unless of course the Indians specifically ask for it. I mean it's not fully fielded so I would doubt Boeing would ship the Indians a better version of it's own fighter that could outshoot the US Navy birds... be kinda embarrassing :) Then again, if the Indians do get the radars, then it'd be after the USN gets them, or when the USN gets enough to feel "safe" in it's own skies. Yes and they claim that the radar could even have been guiding AAMs against aerial targets at the same time(!). That's well... up to speculation, but possible, I guess, not sure on the true capabilties meself. Then again it's not like JDAMs need constant correction, feed them the coordinates, and drop them and then move on to the A2A portion. Homepage | Discord | My Files | YouTube 'Nearly everyone felt the need to express their views on all wars to me, starting with mine. I found myself thinking, “I ate the crap sandwich, you didn’t, so please don’t tell me how it tastes.”' - CPT Cole, US Army
Mugatu Posted March 3, 2008 Posted March 3, 2008 At different times! The only extra beams are the main lobe and side lobes. The software will task the radar to perform different scans reducing the time spent performing other tasks. The notion of multiple beams is a furfy!! A radar with an AESA antennae can generate multiple beams, AFAIK.
D-Scythe Posted March 3, 2008 Posted March 3, 2008 At different times! The only extra beams are the main lobe and side lobes. The software will task the radar to perform different scans reducing the time spent performing other tasks. The notion of multiple beams is a furfy!! Just parroting what I've heard about U.S. AESA radars. Generating multiple radar beams and directing them in different directions seems to be considered standard feature for American AESA sets.
Mugatu Posted March 3, 2008 Posted March 3, 2008 http://www.es.northropgrumman.com/ASD/brochures/AESA_DFOISR_Edited_06_May_2003.pdf pg 14 APG-77 has one array - one main beam SPY1-D 3 arrays 3 beams... MESA Wedgetail etc (arguably the most advanced AESA radar out there) 4 arrays.
D-Scythe Posted March 3, 2008 Posted March 3, 2008 http://www.es.northropgrumman.com/ASD/brochures/AESA_DFOISR_Edited_06_May_2003.pdf pg 14 APG-77 has one array - one main beam SPY1-D 3 arrays 3 beams... MESA Wedgetail etc (arguably the most advanced AESA radar out there) 4 arrays. I don't know what you're arguing. You have provided no evidence that the APG-77 cannot dedicate one group of AESA tiles to transmit in one direction and another group to transmit in another. Also, the SPY-1 isn't even an AESA array - it's PESA. I'm talking about the SPY-3. And yes, it's like to be set up using multiple arrays, just like the SPY-1 - however, this STILL does not disprove the fact that one array can generate many radar beams simultaneously.
Mugatu Posted March 3, 2008 Posted March 3, 2008 Well the physics are pretty obvious, there's a reason why the more T/R modules there are on an array the better ... I'm not arguing just trying to steer your curiosity in the right direction. I don't know what you're arguing. You have provided no evidence that the APG-77 cannot dedicate one group of AESA tiles to transmit in one direction and another group to transmit in another. Also, the SPY-1 isn't even an AESA array - it's PESA. I'm talking about the SPY-3. And yes, it's like to be set up using multiple arrays, just like the SPY-1 - however, this STILL does not disprove the fact that one array can generate many radar beams simultaneously.
D-Scythe Posted March 3, 2008 Posted March 3, 2008 Well the physics are pretty obvious, there's a reason why the more T/R modules there are on an array the better ... I'm not arguing just trying to steer your curiosity in the right direction. Obviously with more T/R modules to play with the more powerful the radar becomes, and the more things it can do. My position is that it's entirely possible that an AESA radar be capable of dividing its whole array into several smaller sub-arrays dedicated to transmitting and steering it's own radar beam. Having more T/R modules in this case means either more powerful sub-arrays or quantitatively more sub-arrays. EDIT: I'm only talking about transmission here. Reception of reflected radar waves can easily be done with the entire array acting as a unit. The physics behind *that* seem to be pretty obvious too.
Pilotasso Posted March 3, 2008 Posted March 3, 2008 But one thing I have to grant Mogatu, is that time sharing beams will provide you with the best perfomance. The time intervals are so small that the targeted aircraft would only move a fraction of an inch since its last tracked position, i.e negligeble difference for guiding wepons. Multiple beams by deviding the tiles decreases range and the gain in precision wont be worth it IMHO. .
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