Chinese Radar Developments - KLJ series and others

Brumby

Brumby

Major
Bltizo said:
We have no basis to speculate that Yankeesama has no reason to be making the apples and oranges comparison.

In fact, there is exactly a reason for us to believe Yankeesama is making that apples and oranges comparison, because in the post he had also stated that N035E is less powerful than current Chinese AESAs. In other words, it is entirely reasonable to assume that he is making the apples and oranges comparison because it is consistent with his other statement that N035E is less powerful than current Chinese AESAs.


The only way in which you could try to interpret it in another way is if there is a widely accepted rule that the look up range of a radar is equal or approximate to the look down range of a radar (which I will address below).





The entire crux of your argument for why you believe Yankeesama's statements about the N035E vs J-16's radar (and current Chinese AESAs) is dependent on what the relationship between a fighter radar's look up range vs look down range is.

It is fine for you to use the N035E's numbers. 152/129km means look up range is 18% longer than look down range. ZhukAE's 130/120km means look up range is only 8% longer than look down.

However, I also listed the specs for a US radar for the F-16 on the last page, which showed APG-66V1's look down range is listed as 20-30 nm, its look up range is listed as 25-40 nm; as well as APG-66V2's look down range is listed as 24-36 nm, its look up range is listed as 29-48 nm.
Being consistent and using the high end number for both look up and look down ranges for both variants, we get:
APG-66V1 40/30nm; look up is 33% longer than look down
APG-66V2 48/36nm; look up is again 33% longer than look down.

A 33% difference is far from marginal and is well within what I would consider to be significant. Even a 20% greater range would be significant.

So, for the purposes of our discussion, we are wanting to settle what Yankeesama meant by comparing the look up range of N035E with the look down range of J-16's AESA.
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You choose to use percentages because it suits your argument.
What do we have :
No35E 152/129, difference of 23 km
Zhuk AE 130/120 difference of 10 km
Even your own choice selection :
APG-66(v)1 30/20 nm difference of 10nm = 18 km
APG-66(v)2 36/24 nm difference of 12 nm = 22 km

Bltizo said:
First of all, we need to accept that it is black and white where he said that N035E is weaker than present Chinese AESAs. There is no room for interpretation there, and this statement will inform what he meant when comparing N035E with J-16's AESA.
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The problem is you are not accepting what he actually said in black and white and I quote "it's substantially weaker than the current generation of Chinese AESAs". You are conveniently choosing to omit the word "substantially". Omitting a single word changes the entire meaning. I actually expected a higher standard from you than resorting to selective editing to suit your argument.
 
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Blitzo

Blitzo

Lieutenant General
Staff member
Super Moderator
Registered Member
Brumby said:
You choose to use percentages because it suits your argument.
What do we have :
No35E 152/129, difference of 23 km
Zhuk AE 130/120 difference of 10 km
Even your own choice selection :
APG-66(v)1 30/20 nm difference of 10nm = 18 km
APG-66(v)2 36/24 nm difference of 12 nm = 22 km
Click to expand...

I "choose" to use percentages because the relationship between look up and look down modes for different radars should be consistent.

The APG-66V1 has an absolute difference of 10nm between look up and look down range. APG-66V2 has an absolute difference of 12nm between look up and look down range.

Note how the absolute difference is greater in the APG-66V2 vs the APG-66V1, yet the ratio between look up vs look down remains the same. For both radars, the look up range is 33% higher than the look down range.



The problem is you are not accepting what he actually said in black and white and I quote "it's substantially weaker than the current generation of Chinese AESAs". You are conveniently choosing to omit the word "substantially". Omitting a single word changes the entire meaning. I actually expected a higher standard from you than resorting to selective editing to suit your argument.
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I'm not conveniently choosing to omit anything, I just can't be bothered going back to the post and copying the exact comment every time I reply to you.

For the sake of discussion, pretend every time I talked about what he wrote, that I had written "it's substantially weaker than the current generation of Chinese AESAs" in those exact words, because it doesn't change my argument.
 
Jura The idiot

Jura The idiot

General
Brumby said:
Good question. I have already explain it in a couple of other post and provided the numbers specific to the conversation. It is generally true because the background scattering is more pronounce with look down.

View attachment 51567
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good, so if it's true plus looking at this part of
#341 Brumby, Today at 5:50 AM
:
Brumby said:
...
What do we have :
No35E 152/129, difference of 23 km
Zhuk AE 130/120 difference of 10 km
Even your own choice selection :
APG-66(v)1 30/20 nm difference of 10nm = 18 km
APG-66(v)2 36/24 nm difference of 12 nm = 22 km

...
Click to expand...
, there isn't "contradiction" which you asserted
#5044 Brumby, Saturday at 1:55 AM

Su-35 look-up similar to J-16 look-down implies a higher J-16 look-up
 
L

latenlazy

Brigadier
Jura said:
good, so if it's true plus looking at this part of
#341 Brumby, Today at 5:50 AM
:
, there isn't "contradiction" which you asserted
#5044 Brumby, Saturday at 1:55 AM
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Basically, the difference between look up and look down isn’t “slight” as Brumby originally suggested, which is at the basis of his assertion that the J-16’s radar must be equivalent to the Su-35’s in range. It’s significant. Everywhere I’ve look the figures consistently say look down is about 30% smaller in range than look up due to backscatter, though with a lot of variance depending on conditions like how close to the ground you are.
 
Jura The idiot

Jura The idiot

General
Brumby said:
You choose to use percentages because it suits your argument.
What do we have :
No35E 152/129, difference of 23 km
Zhuk AE 130/120 difference of 10 km
Even your own choice selection :
APG-66(v)1 30/20 nm difference of 10nm = 18 km
APG-66(v)2 36/24 nm difference of 12 nm = 22 km



The problem is you are not accepting what he actually said in black and white and I quote "it's substantially weaker than the current generation of Chinese AESAs". You are conveniently choosing to omit the word "substantially". Omitting a single word changes the entire meaning. I actually expected a higher standard from you than resorting to selective editing to suit your argument.
Click to expand...
latenlazy said:
Basically, the difference between look up and look down isn’t “slight” as Brumby originally suggested, which is at the basis of his assertion that the J-16’s radar must be equivalent to the Su-35’s in range. It’s significant. Everywhere I’ve look the figures consistently say look down is about 30% smaller in range than look up due to backscatter, though with a lot of variance depending on conditions like how close to the ground you are.
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I would've brought to Aristoteles this:

radars have a look-up range value higher than a look-down range value [major premise]
Su-35's look-up range is about the same as J-16's look-down range [minor premise]
therefore, J-16 has a better radar than Su-35 [conclusion]

dated April 1st, 2019
 
O

ougoah

Brigadier
Registered Member
Can you guys not see Brumby is being purposefully difficult and trolling albeit in a relatively polite and passive aggressive way? I mean he chose to use absolute values rather than proportional ones to measure ranges. That alone is indicative enough of how sly he's trying to be. Did you also not notice the backhanded judgement remark on "this forum" for being too emotional and sensitive to deal with his numbers proving F-16's APG83 has better range than J-16's AESA? Then conveniently not showing those "numbers" to avoid further embarrassment. Numbers convey proof after all. None of this speculation is really worthy of discussion. The vacuum of news and updates has encouraged measuring contests like these exchanges. We don't know anything of J16's radar performance beyond some admittedly reputable sources (reputable as one can get by disclosing accurate information before they become mainstream). Take those comments how you will but they are quotable and are far superior measures than anything anyone else can come up with because no other public group has as much reputation for accuracy and insider info than some of these sources.
 
T

Tam

Brigadier
Registered Member
Xsizor said:
Afaik , NRIET is the only institute devoted to fighter jet radars and produces the KLJ series radar. This is quite odd as there ought to be some competitor institute. NRIET surely isn't the only institute for AESAs. Which institute handles the Ship borne AESAs ? Do they have separate institutes for naval AESA solutions ? Or does NRIET produce the Naval AESAs too ( under a subsidiary or offshoot) ? Surely, NRIET wouldn't have been the only AESA provider for J-20 4th gen fighter program. I am forced to ask this as I distinctly remember reading about another institute ( or AESA Radar ) competing against NRIET , one year ago.
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There are likely to be different competing institutes, however, NRIET has proven itself.

NRIET is also known as Institute 14, and yes, it is Institute 14 that designed the Type 346/346A/346B radars for the Type 052C/052D/055. Note that for aircraft radars, NRIET's Type 1473 for example, 14 means Institute 14. Type 1473 if I remember is the J-10's original slotted array PD radar.

Not sure who is responsible for other naval radars, for example, the popular Type 364 that has been a standard with modern PLAN vessels since the Type 052B and is only replaced on the Type 055.

A competing institute is Institute no. 23, who is responsible for the HT-233 fire control phase array for the land based HQ-9. Note the "23" in the "233".
 
Quickie

Quickie

Colonel
siegecrossbow said:
He is talking about the J-16, not F-16!
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Okay, I misread that one. After all, he did mention about competing with F-16 AESA. Any which way, the proper way is to compare radar of similar size (i.e. same number of antenna elements) since they're using a similar type of transmitter-receiver semiconductor driver (GaN) of similar output power. Otherwise, it won't be an apple to apple comparison even if the larger radar won on pure raw transmitter power.
 
Xizor

Xizor

Captain
Registered Member
Tam said:
There are likely to be different competing institutes, however, NRIET has proven itself.

NRIET is also known as Institute 14, and yes, it is Institute 14 that designed the Type 346/346A/346B radars for the Type 052C/052D/055. Note that for aircraft radars, NRIET's Type 1473 for example, 14 means Institute 14. Type 1473 if I remember is the J-10's original slotted array PD radar.

Not sure who is responsible for other naval radars, for example, the popular Type 364 that has been a standard with modern PLAN vessels since the Type 052B and is only replaced on the Type 055.

A competing institute is Institute no. 23, who is responsible for the HT-233 fire control phase array for the land based HQ-9. Note the "23" in the "233".
Click to expand...
There is much information hidden behind the seemingly weird numbering system within the MIC of PLA. Thank you for the enlightenment.
 
T

Tirdent

Junior Member
Registered Member
It is correct that in more recent PD radars look down range is no longer terribly different from look up range (APG-66 is hardly a representative radar any more these days, and the overlapping ranges for l/d and l/u performance respectively render those figures rather useless for comparison). Doppler filtering works extremely well nowadays.

So what that Chinese source implicitly tells us is that the J-16 radar effectively is slightly longer ranged (maybe 10 - 15%) than the Irbis in the Su-35 - fair enough. They both have about the same antenna diameter, they're both X-band (meaning the number of radiating elements and hence antenna gain will be very close) and, as the Bars/Irbis family of PESAs uniquely have an AESA-like distributed receive signal path, very similar receiver sensitivity. Assuming the J-16 AESA has a fairly typical per-element transmit power of around 10W and a TRM count of some 2000 modules (X-band, 0.9m diameter array) we get a transmitter power in the same 20kW ball park as the Irbis' centralized two-stage TWT (which however implies wave guide losses that don't accrue in an AESA). Makes sense, the available cooling and generator capacity (if that's the long pole in the tent) should also match closely, given the related airframe platforms.

Antenna gain similar, transmitter power similar (with an advantage for the AESA, due to not suffering wave guide losses), receiver sensitivity similar - radar range equation says they'll be close, lo & behold, they are. I don't see why this is such a big deal - there's nothing very much surprising about it, just basic physics.
 
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