F-35 vs Su-30/35

The F-35 compared with other modern jets.
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sergei

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Unread post08 Apr 2015, 17:52

hornetfinn wrote:
sergei wrote:The problem is that before turn on the radar you do not know what is near, is it large RCS target like bomber? or it may be small fighter very far away? To track large RCS target do not need many power it is true, but to that would be confident in discovering new targets at maximum range you must use the maximum power.


There is really no problem. If you are flying at 10,000m or about 33,000ft, then any threat +/- 5 degrees is closer than 100 km away and +/- 10 degrees is closer than 50 km away. So multiple simultaneous beams could very safely be used below and above those elevations



I honestly do not really understand you :?
If the target is rejected by less 5 degrees relative to the center it more 100km away ?
Detection accuracy of + -50 km is just amazing :drool:

P/S Maybe you tried to say : that for target shift perpendicular to the direction of flight of the aircraft radar performance falls?
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Unread post08 Apr 2015, 19:17

sergei wrote:I did not even try,the purpose of my staying there is not in the set of reputation and not propaganda- it is education itself.


You're trying to educate yourself? Good for you. You might start by reading other people's posts.
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XanderCrews

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Unread post08 Apr 2015, 19:47

sergei wrote:I did not even try,the purpose of my staying there is not in the set of reputation and not propaganda- it is education itself.


Cool, when does that start?
Choose Crews
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eloise

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Unread post09 Apr 2015, 06:31

sprstdlyscottsmn wrote:
eloise wrote:btw not very related, but here a graph of Su-27 RCS with and without RAM

So it's between 10 and 30 dB in the front area?

without RAM it fluctuating between 20-30 dBsm t the front
with RAM it only around 10 dBsm
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eloise

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Unread post09 Apr 2015, 06:36

sergei wrote:I honestly do not really understand you :?
If the target is rejected by less 5 degrees relative to the center it more 100km away ?
Detection accuracy of + -50 km is just amazing :drool:

P/S Maybe you tried to say : that for target shift perpendicular to the direction of flight of the aircraft radar performance falls?

no, try to image the radar field of view as a triangle or a cone
you only need a very narrow angle to cover huge area- (volume ) at long-distance , the shorter the distance the bigger angle you will need

look at the image below
Image
when the angle remains the same the higher the height the bigger the base
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hornetfinn

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Unread post09 Apr 2015, 06:47

sergei wrote:
hornetfinn wrote:
sergei wrote:The problem is that before turn on the radar you do not know what is near, is it large RCS target like bomber? or it may be small fighter very far away? To track large RCS target do not need many power it is true, but to that would be confident in discovering new targets at maximum range you must use the maximum power.


There is really no problem. If you are flying at 10,000m or about 33,000ft, then any threat +/- 5 degrees is closer than 100 km away and +/- 10 degrees is closer than 50 km away. So multiple simultaneous beams could very safely be used below and above those elevations



I honestly do not really understand you :?
If the target is rejected by less 5 degrees relative to the center it more 100km away ?
Detection accuracy of + -50 km is just amazing :drool:

P/S Maybe you tried to say : that for target shift perpendicular to the direction of flight of the aircraft radar performance falls?


No, what I meant was this:

1. If you fly at 10,000 m altitude and you look down more than 5 degrees from horizon, a target is definitely closer than about 100 km (actually about 114 km at sea level) or it would be below ground which is not good for aircraft.

2. If you fly at 10,000 m altitude and you look up more than 5 degrees from horizon, a target is definitely closer than about 100-120 km or it would be be flying at above 20-21,000 m and not many threat systems can do that.

3. If you fly at 10,000 m altitude and you look down more than 10 degrees from horizon, a target is definitely closer than about 50 km (actually 57 km at sea level) or it would be below ground.

4. If you fly at 10,000 m altitude and you look up more than 10 degrees from horizon, a target is definitely closer than about 50-60 km or it would be be flying at above 20-21,000 m.

5. Of course a target can be very close no matter the elevation/depression angle, but it elevation/depression angle sets the limits how far it can be.

Because you know that the target can not be further away than this, you can safely use multiple simultaneous beams to search for new targets as using all the power would be unnecessary and increasing search area/volume is very necessary. Of course a lot depends on situation, expected threat and what the mission is. Also a flight of AESA equipped fighters (especially F-35 with advanced datalinking and sensor/data fusion) can share the workload so that some fighters could look for long distance targets only and some would search for closer targets with very large search areas. A fighter could also look for long distance (low elevation/depression) targets 80 percent of the time and once in a while take a look at high elevation/depression (closer) targets rest of the time with multiple simultaneous beams. AESA equipped fighters have much more tactical options available than PESA or MSA equipped fighters have.
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Unread post09 Apr 2015, 06:56

eloise wrote:
sprstdlyscottsmn wrote:
eloise wrote:btw not very related, but here a graph of Su-27 RCS with and without RAM

So it's between 10 and 30 dB in the front area?

without RAM it fluctuating between 20-30 dBsm t the front
with RAM it only around 10 dBsm


If those values are true for the actual fighter, then it has huge RCS (up to several hundred square meters). No wonder Bars radar is said to have detected Su-27 330 km away even though it can detect MiG-29 only at 140 km away.

Where that graph is from?
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ata

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Unread post09 Apr 2015, 11:32

OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)
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sergei

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Unread post09 Apr 2015, 12:08

ata wrote:OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)

100% you russian troll , you dont understend AESA work!! :mrgreen:
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ata

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Unread post09 Apr 2015, 12:20

sergei wrote:
ata wrote:OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)

100% you russian troll , you dont understend AESA work!! :mrgreen:


Of course :) In fact I'm not very experienced in radar tech, but I've developed several AESA antennas for telecom usage. Of course there is difference in power management for example, but basics is the same.
BTW there are several NAVAL multi-beams radars (even made in Russia by tovarishchs), but that guys are not limited in power and size.
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eloise

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Unread post09 Apr 2015, 14:48

ata wrote:OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)


AESA can transmit emissions by a proportion of it's total T/R modules number but it will always received reflected signal by all of them, thus the gain always remain the same
ata wrote:I've developed several AESA antennas
.

are you sure u not lying this time?
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Unread post09 Apr 2015, 14:53

hornetfinn wrote:Where that graph is from?

some Russian study for plasma stealth, they want to put a plasma screen in front of the radar, and paint the fan blade with RAM
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sergei

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Unread post09 Apr 2015, 14:54

eloise wrote:
ata wrote:OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)


AESA can transmit emissions by a proportion of it's total T/R modules number but it will always received reflected signal by all of them, thus the gain always remain the same
ata wrote:I've developed several AESA antennas
.

are you sure u not lying this time?

Always? always? always? to me it "to big to fail" claim= False
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sergei

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Unread post09 Apr 2015, 15:37

eloise wrote:sergei , your comment shown that you have very limited knowledge about radar or how they work
here are some link about radar range equation : have a read ( carefully ) , try to understand it before you comment anything , they said the same thing with different number so it may be a bit hard to understand if you not good at math :?
Image
where

S = signal energy received by the radar
Pavg = average power transmitted by the radar
G = gain of the radar antenna
σ = radar cross section of the target
Ae = effective area of the radar antenna, or "aperture efficiency"
tot = time the radar antenna is pointed at the target (time on target)
R = range to the target

According to this relationship, reducing the radar cross section of a vehicle to 1/10th of its original value will reduce the maximum range at which the target can be detected by nearly 44%! While that reduction alone is significant, even greater reductions in RCS are possible.

An aircraft that reduces its front aspect signature by a factor of 10 cuts the notional detection range by 44 percent.

it take 95 % RCS reduction to reduce radar detection range by 50 %, and a 99 % reduction in signature reduce radar detection range by 67 % .

http://www.aerospaceweb.org/question/el ... 0168.shtml
https://books.google.com.vn/books?id=Ut ... ge&f=false
http://anagnostou.sdsmt.edu/2007Fall/RC ... Ch2.17.pdf
https://books.google.com.vn/books?id=rz ... ge&f=false

https://books.google.com.vn/books?id=0W ... ge&f=false
sergei wrote:F15
The APG-63 has a range of 100 miles (87 nmi; 160 km) no near 400km
F14
The APG-71 system itself is capable of a 700 km range, but the antenna design limits this to only 370 km
F22
The APG-77 201–241 km at best and unofficially 193 km for a 1 m2 target
F35
APG-81 80-85nm for Su-27 whose RCS greater than 10
"Apg-81 can track target with RCS = 1m2 from 150 km so according to radar equation APG-81 can track target with RCS = 10 m2 from 270 km"
False statement ,that it were true This information should look strictly contrary-just as looking your information for Zaslon-m

Now after you understand the basic of radar equation above , here are the radar tracking range they calculate from available public information ( you can also calculate Zaslon-M range from public figure by yourself based on the radar equation)
Image
Image
here is the Su-35 Irbis-e range based on public figure
Image
( btw the most modern F-15 now using APG-63v3 and AN/APG-82 , which have much better range than APG-63v2 )

sergei wrote:And ?

that was 30 years before the F-35 , F-35 can atleast achieve the same level of RCS reduction , and as i have explained it not hard to keep your enemy within 45 degree from your nose ,and you should also remember that at wide angle Su-35 will have very high RCS too


sergei wrote:And you think that the pilot simply ignored the appearance on the radar 2 hostile objects If it see them from 300km?

no , but closer target equal higher threat level

sergei wrote:To maximize the effect of the TVC engines on the aircraft must be much farther apart than Rafale and typhoon

really ? , why ? F-22 TVC is not very further apart , Aim-9X still have TVC despite the fact that it only have 1 engine :|
do you really think that put TVC on 2 engine further apart will have better effect on turn rate than if they were close together ?
btw you havenot answer my question : how long does it take for Su-27 or Su-35 to accelerate from mach 0.8 to mach 1.2 when it is aimed with 4 missiles ? ( or 10 missiles since russian fan boy often like to brag about how many AAM their su-27 can carry )

sergei wrote:"if the missiles was launched at beyond visual range how do they even know if the target was maneuvering or not ? "
Turn ON your brain-because they launch it themselves.

no , you should turn On your brain
the only available information was recorded by USAF is the number of missiles kill , and distance to target , the assessment that targets dont try to evade Aim-120 is a make up statement by APA , not a fact

That seemed to me that this familiar graph

http://www.ausairpower.net/XIMG/FA-22A- ... 05-APA.png


IT is APA!!!!!
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Unread post09 Apr 2015, 15:45

eloise wrote:
ata wrote:OMG....
1/7 of power....
7 beams...
AESA can do what PESA can't...

I'd like to ask the very simple question why the hell AESA radars need so many basic modules in that case? Do you hear about GAIN? Your power (15W, 30W, brazillon watts) means nothing if you have no enough gain. This is a reason why so many modules are used. The more modules you have the more GAIN you have in a peak point. In other words to focus beam without wasting power to heat up the atmosphere you need all the basic oscillators you have. What would be your gain for each of 7 beams?
Moreover munny if you already know what equation is, you probably can see that gain is squared, while for power there is a linear function. So having 3dB less gain you need 4 times more power to compensate it. It's math basics, you probably need to go back to the school or finish the school first.
And yes it's possible to create even more beams than 7. How many you want? You can create a lot. With 0dB gain for every of them.
Moreover, PESA in general is able to create more powerful beam in single point. There is completely different reason why AESA is more preferable in military applications than PESA. But it's another one more advantage of "western" aircrafts, which would be too much for such a fantastic tool as F-35 :)


AESA can transmit emissions by a proportion of it's total T/R modules number but it will always received reflected signal by all of them, thus the gain always remain the same
ata wrote:I've developed several AESA antennas
.

are you sure u not lying this time?


:doh:

I would send you to the theory how AESA works and how it generates it's directivity pattern. Please, check how AESA gain depends of number of modules. It's not like 2 times less modules - two times less gain :D
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