055 DDG Large Destroyer Thread


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Tam

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You should use the windows as a gauge. The 055 array has an extra half window length.
 
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The Observer

Junior Member
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You should use the windows as a gauge. The 055 array has an extra half window length.
Well, nope. I still stand by my argument even after using the windows as the gauge.

052D and 055 just have the same Type 346 radar size. The T/R modules might be different, but in pure total size? nope.

052D and 055.jpg
 

Lethe

Senior Member
Definitely bigger.

On the 052D, the arrays are about 5 windows wide while the on the 055, the arrays are about 6 windows wide. This is remarkable because each window might be about a meter or less. Furthermore the IFF bars on top of the arrays are different. On the 055' they are much bigger and thicker.

Can we be confident that the windows are the same size and thus a suitable basis for comparison? The Type 1130 might serve as a better baseline...
 

kickars

Junior Member
Can we be confident that the windows are the same size and thus a suitable basis for comparison? The Type 1130 might serve as a better baseline...
True, but one thing is also for certain is that the windows on 055 are definitely no smaller than the ones on 052D.
 

Lethe

Senior Member
Ok I see the advantage of using windows: they are in the same plane as the radars so eliminate the problem of perspective distortion.
 

Tam

Brigadier
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Well, nope. I still stand by my argument even after using the windows as the gauge.

052D and 055 just have the same Type 346 radar size. The T/R modules might be different, but in pure total size? nope.

View attachment 79100


I still disagree with you. I have measured this before, and I know someone else also did. You are using outline which is still subject to a bit of distance and pixel distortion with algorithmic corrections. If you see the third 052D at the back, the domes of the Type 364 and 366 radars are a bit smaller than the 052D on the front. The 055's radars are bigger but not by much.

But most importantly, the modules have changed. The 055 does not need the Type 517 Yagis like the 052D, so the main radars made the Yagis redundant. The ship also has six generators (QD50 or) so that's a tremendous amount of electricity. The ship also pours out plenty of water near the waterline, which suggests a lot of internal cooling is taking place. So these arrays must be running hotter than the 052D as more power is poured into them.
 
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Stealthflanker

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So, have anyone make a range estimate for those big phased arrays ? Particularly the 346B.


think i can try make one, with some assumptions tho.

wikipedia states that earlier Type 346 have 4x4 meter antenna and S-band. Assuming array fill factor of say 90%. the 4x4 m array can contain about 4522 TRM assuming operational frequency of 3 GHz. The range of this early types is stated to be at least 400 Km.

The type 346B for Type-055 is stated to have 40% larger array. This corrensponds to area of about 17.59 sqm. Assuming same fill factor, the array would contain 6332 TRM. This is about 1.4 Times.

There is simple 4th root rules of thumb one can follow to calculate range based on the module numbers alone.


aesamodule-vs-range-jpg.666105


The deriviation of above can be read from book "Radar Technique using Array Antenna" by Dietrich Wulfer. and the way it is possible to do with such simplicity can be read in Richard G Curry's "Radar System Performance Modeling".

Now with reference range of 400 Km. Assuming same module architecture and same cooling the 346B with that assumption will have increased range with factor of (1.4^3)^(1/4) = 1.28 Times or 514 km.

Now with change of cooling system, what kind of range we can get ? This requires deeper look in cooling capacity. But for sake of simplicity let's assume the designers were able to provide 3 times more power compared to the earlier design with new liquid cooling system. The equations can then be adjusted by adding the power factor in it. Thus :

((1.4^3)*(3))^(1/4) = 1.693 or 1.7 times or 680 Km.

To make deeper insight however more have to be assumed e.g Target RCS and probability of detection which requires target model (e.g Swerling 1 or 2). Then SNR can be determined and used as a basis to estimate sensitivity (using loop gain method) and accuracy( range, doppler and monopulse) of the radar.
 
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