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First Chinese AEW&C ZDK-03 Karakoram Eagle Delivered

can any some on give specs of the radar and indurance tine of aircraft its fited on
 
If I am not mistaken, ZDK-03 features two AESA arrays instead of three on KJ-2000, therefore a rotating dome is needed. The lack of third array is purely a cost saving consideration.
 
If I am not mistaken, ZDK-03 features two AESA arrays instead of three on KJ-2000, therefore a rotating dome is needed. The lack of third array is purely a cost saving consideration.

Thats not the ONLY reason, another reason is that a larger array can be placed in a rotating dome giving more range, while placing triangular dome reduces the size of each array by ~20%.

A simple trignometric analysis shows that the maximum array size of triangular dome (like KJ2000 and Phalcon) is 20% less than a straight radial array along its diameter (like E-3-Sentry, E-2D-Hawkeye, ZDK03).

Moreover, previously the pulse doppler version of rotating domes gave a 20sec radar darkness over any perticular point due to the fact that they could only illuminate targets in direct line of sight in perpendicular to the array, but the AESA doesnot have that restriction. Instead AESA can electronically steer a radar beam to illuminate 60 degrees to either side of perpendicular. This covers 120 degree to each side totalling 240 degrees of instantaneous view, while leaving 60 degree on each corner in radar darkness. When rotating at same speed of 40 sec per rotation, same as with pulse dopler version, it will illuminate a full 360 degree circle in 6 seconds. Thus a target is re-illuminated 6 seconds after it goes into dark region. Also this is assuming ZDK-03 has AESA with 120 degree field of view, which is only an assumption. In actuality it might have 150 degree field of view AESA (like Erieye atop Saab2000) which will reduce re-acquisition time to 3 sec.

One more thing to note is that fixed dome suffers from constant side lobe attenuations in regions deviating close its electronic steering boundary, for extended periods of time; while giving good target data at regions close to perpendicular. On the other hand, rotating dome ensures maximum search precision for all 360 degrees within a maximum of 10 seconds, and that too without changing the heading of the platform itself.

If you ask me, having 20% plus range is much much more desirable than 3 seconds of radar darkness, besides being cost effective as well.

Regards,
Sapper
 
Can we have a comparison of Erieye Saab2000 and ZDK-03"s radars. pls?
 
Thats not the ONLY reason, another reason is that a larger can be placed in a rotating dome giving more range, while placing triangular dome reduces the size of each array by ~20%.

A simple trignometric analysis shows that the maximum array size of triangular dome (like KJ2000 and Phalcon) is 20% less than a straight radial array along its diameter (like E-3-Sentry, E-2D-Hawkeye, ZDK03).

Moreover, previously the pulse doppler version of rotating domes gave a 20sec radar darkness over any perticular point due to the fact that they could only illuminate targets in direct line of sight in perpendicular to the array, but the AESA doesnot have that restriction. Instead AESA can electronically steer a radar beam to illuminate 60 degrees to either side of perpendicular. This covers 120 degree to each side totalling 240 degrees of instantaneous view, while leaving 60 degree on each corner in radar darkness. When rotating at same speed of 40 sec per rotation, same as with pulse dopler version, it will illuminate a full 360 degree circle in 6 seconds. Thus a target is re-illuminated 6 seconds after it goes into dark region. Also this is assuming ZDK-03 has AESA with 120 degree field of view, which is only an assumption. In actuality it might have 150 degree field of view AESA (like Erieye atop Saab2000) which will reduce re-acquisition time to 3 sec.

One more thing to note is that fixed dome suffers from constant side lobe attenuations in regions deviating close its electronic steering boundary, for extended periods of time; while giving good target data at regions close to perpendicular. On the other hand, rotating dome ensures maximum search precision for all 360 degrees within a maximum of 10 seconds, and that too without changing the heading of the platform itself.

If you ask me, having 20% plus range is much much more desirable than 3 seconds of radar darkness, besides being cost effective as well.

Regards,
Sapper


How did you arrive at the 6 second mark?
 
How did you arrive at the 6 second mark?

Now my first assumption is that two complimenting AESAs are placed inside the rotating dome, i.e. the similar kind of double sided Erieye configuration, but in rotating configuration. This is based on the assumption that
1. Dual sided aesa was already available with china on Y-8 platform at similar cost, but not opted for by PAF,
2. AESA is comparatively thin and does not require additional wasted space for dedicated transmitter assembly on the backside, since every single unit is itself a transmitter reciever on its own.
3. China already posses the technology to fit 3xAESA in a radome and 2xAESA in sandwitch-BalanceBeam configurations, placing the balance beam config would have been no problem to place into a rotating radome.

If thats the case for ZDK-03 (unless proven on the contrary) I will proceed with the following calculations.


Assume 40 sec per rotation, which is normal, and 120 arch illumination (60 deg from perpedicular) for AESA array, which is also normal.
360 deg per 40 sec = 9 deg per sec (RotationSpeed)

Assume a target is at 0-deg, Radar starts spinning, at radar's-0-deg, target is fully perpedicular and perfectly lit
Radar goes to 45-deg, still lit.
Radar goes 60-deg, still lit.
Radar goes 61-deg, target lost.
Now radar goes 90-deg, target is still lost.
Radar goes 119-deg, still lost.
Now radar comes to 120 deg, still lost for the array pointing 120, but the array facing exactly opposite to it i.e. at 120+180 deg = 300-deg has illumination till 360 deg, which is the same as 0-deg, target lit by opposing array, target acquired.

Now target lost at 61-deg ... and reacquired at 120-deg.
Lost-Time = 60-deg / RotationSpeed = 60 / 9 = 6.6 sec


I may be wrong, and ZDK-03 might only have a single AESA pointing to one side, as in legacy E3Sentry, in which case the re-acquisition will take 26 seconds to re-acquire target, but lets wait for the time when PAF or China releases specs. If thats the case apologies in advance.

Regards,
Sapper
 
19331237_2015022811272388986700.jpg
 
If I am not mistaken, ZDK-03 features two AESA arrays instead of three on KJ-2000, therefore a rotating dome is needed. The lack of third array is purely a cost saving consideration.

That's before the many upgrades
 

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