J-20 5th Gen Fighter Thread IV (Closed to posting)

[Skywatcher]

The best they can hope for is early detection and interception. That said, I'm simply not convinced that they could do that in time given their constrained air space.

And there's the matter of the PLA just firing stand off weapons at the bistatic elements.

 

[Engineer]

That is a big statement especially if nobody in China had opportunity to actually measure RCS of F-22.

Nobody in China would need to do an actual RCS measurement. China developed its own stealth fighters, meaning it also has all the means to figure out the RCS of an aircraft from the design alone.

Btw , lets play games some more : even if the RCS of F-22 is 0.01 sqm ( and this is outrageous claim ) radar that would be able to detect it at 200 km would detect standard fighter-sized target of 5sqm at 945km - much better than any fighter radar today .

The extract within the diagram says RCS of F-22 is 0.1 m[sup]2[/sup], not 0.01 m[sup]2[/sup]. The claimed detection range of 280 km is based off of the 0.1 m value.

 

[Air Force Brat]

Nobody in China would need to do an actual RCS measurement. China developed its own stealth fighters, meaning it also has all the means to figure out the RCS of an aircraft from the design alone.


The extract within the diagram says RCS of F-22 is 0.1 m[sup]2[/sup], not 0.01 m[sup]2[/sup]. The claimed detection range of 280 km is based off of the 0.1 m value.

Well that's an interesting idea, but the gentlemen who know the actual numbers aren't talking, so if some US expert proclaims the RCS of the J-20 is about that of an F18 you're gonna buy that right???? Extrapolations are just that without actual data, but truthfully a lot can be discerned by the truly intuitive, but its very unlikely that either side has any actual data on the other fella's bird, UNLESS----HUUUUMMMMHHHH!

 

[Engineer]

Well that's an interesting idea, but the gentlemen who know the actual numbers aren't talking, so if some US expert proclaims the RCS of the J-20 is about that of an F18 you're gonna buy that right????

There are differences between knowing the other side's capabilities and talking publicly about the other side's capabilities. There are also differences in what are disseminated to the public and what are exchanged in private.

Extrapolations are just that without actual data, but truthfully a lot can be discerned by the truly intuitive, but its very unlikely that either side has any actual data on the other fella's bird, UNLESS----HUUUUMMMMHHHH!

By now, both sides would have done plenty of computer and physical simulations on the other side's fighter. So even in the absence of actual data, I am pretty sure both sides have a pretty good idea about the RCS figure of the other side's fighter.

 

[latenlazy]

There are differences between knowing the other side's capabilities and talking publicly about the other side's capabilities. There are also differences in what are disseminated to the public and what are exchanged in private.


By now, both sides would have done plenty of computer and physical simulations on the other side's fighter. So even in the absence of actual data, I am pretty sure both sides have a pretty good idea about the RCS figure of the other side's fighter.

I wouldn't be surprised if cyber espionage gave them an important window to increase the accuracy of their simulations on capabilities.

 

[Skywatcher]

Nobody in China would need to do an actual RCS measurement. China developed its own stealth fighters, meaning it also has all the means to figure out the RCS of an aircraft from the design alone.


The extract within the diagram says RCS of F-22 is 0.1 m[sup]2[/sup], not 0.01 m[sup]2[/sup]. The claimed detection range of 280 km is based off of the 0.1 m value.

0.1m2 for the F-22A? Is that when it has the "radar reflector" when flying around in civilian airspace?

 

[Air Force Brat]

There are differences between knowing the other side's capabilities and talking publicly about the other side's capabilities. There are also differences in what are disseminated to the public and what are exchanged in private.


By now, both sides would have done plenty of computer and physical simulations on the other side's fighter. So even in the absence of actual data, I am pretty sure both sides have a pretty good idea about the RCS figure of the other side's fighter.

You are so right my friend, I don't have to tell you that I have the greatest respect for your in-sight and count you as a true friend, I admire your honesty and find your candor refreshing, your ability to access all the angles is admirable. I would still love to see some blue smoke on the J-20 in the wind tunnel, but you helped me put the pieces together, for that matter I would like to see some blue smoke on the F-22... brat.

 

[thunderchief]

Nobody in China would need to do an actual RCS measurement. China developed its own stealth fighters, meaning it also has all the means to figure out the RCS of an aircraft from the design alone.

Unfortunately , non sequitur . If China managed to achieve just 0.1 sqm it doesn't mean that other countries do not have better technologies .

The extract within the diagram says RCS of F-22 is 0.1 m[sup]2[/sup], not 0.01 m[sup]2[/sup]. The claimed detection range of 280 km is based off of the 0.1 m value.

Well , RCS of F-22 may not be good as advertised , but I'm certain it is far below 0,1 sqm . Btw , even Eurofighter Typhoon supposed to have better RCS than that in clean configuration (0.075 sqm ) . And yes , 280km for 0.1 sqm would entail 744 km for 5 sqm target .

 

[Engineer]

Unfortunately , non sequitur . If China managed to achieve just 0.1 sqm it doesn't mean that other countries do not have better technologies .

You just made a strawman fallacy, where you created and retorted a fictitious argument rather than actually replying to my statement. No where in my statement did I ever said China achieved just 0.1 m[sup]2[/sup] RCS on their best fighter. Neither did my statement make any claim on who has better technologies.

My statement concerns with the techniques China employed in analysis of J-20 being used for analysis of F-22. You bringing in technologies is irrelevant to my statement about analysis techniques.

Well , RCS of F-22 may not be good as advertised , but I'm certain it is far below 0,1 sqm . Btw , even Eurofighter Typhoon supposed to have better RCS than that in clean configuration (0.075 sqm ) .

Such discrepancies can be explained by the different parameters used to compute the RCS figure. An aircraft company selling a stealth or semi-stealth fighter would quote the lowest RCS value resulted from using a specific frequency and a specific look angle, whereas a radar company would use parameters that maximize the RCS value.

And yes , 280km for 0.1 sqm would entail 744 km for 5 sqm target .

The image already addressed this. At the same altitude at which the 280 km detection range can be achieved, the maximum observation range of a target of any size is only 383 km.

 

[Skywatcher]

Such discrepancies can be explained by the different parameters used to compute the RCS figure. An aircraft company selling a stealth or semi-stealth fighter would quote the lowest RCS value resulted from using a specific frequency and a specific look angle, whereas a radar company would use parameters that maximize the RCS value.

And at what possible specific frequency and look angle could the F-22A have a 0.1m2 RCS? I can buy 0.01m2 or even 0.05m2.