CAC J-20 vs. F-22 and other technical issues

[gambit]

Well I beg to differ,...

You may, but it still does not mean you know what you are talking about. Observe...

EOTS and EODAS all has the ability to work out speed and aspect angle...these two sensors sending continuous target data to the fire-control system, and the fire-control system combines its won platform data, like its speed, heading, altitude and angle, so the fire-control system will calculate these data, to get a synchronous data of the target.

EOTS starts scan mode to overview the area, find any target, combined with its own platform's flying posture

See the highlighted? Am going to give you ONE CHANCE to explain what it mean.

You have ONE CHANCE to explain to the forum the precise operation(s) on how passive sensor data reveals target resolution of...

- Altitude
- Speed
- Heading
- Aspect angle

What you did was nothing more than translate from Chinese into English. Convince me that you are able to translate the words into operating principles.

This is gonna be entertaining...

 

[ozranger]

Well I beg to differ, optical sensors like EOTS and EODAS can work out target's speed, heading, altitude and angle```

since you cant read Chinese, I can only try to explain in English
EOTS and EODAS all has the ability to work out speed and aspect angle...these two sensors sending continuous target data to the fire-control system, and the fire-control system combines its won platform data, like its speed, heading, altitude and angle, so the fire-control system will calculate these data, to get a synchronous data of the target.

EOTS starts scan mode to overview the area, find any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target after each scan, and between two scans, there is a time difference + changes of target's flying posture, so the speed can be worked out```

each EODAS lense uses gazing mode, overview the area, gaze up on any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target too, and the target coordination labling is continous, so there is the track

and then the fire-control system fuses all of those info from EODAS and EOTS, to find out angle of relativity to each sensors, sellecting the lables with closest time difference, hence the target's speed, aspect angle, altitude and heading can be worked out```````

I paste the Chinese part, just in case anyone has better English`````

4代机上面的光电系统，都必须能够对探测到的信号进行角度跟踪，无论是EOTS，或者是EODAS。它们只需要向火控系统连续提供所探测到的目标角度跟踪数据，火控系统会根据载体的飞行姿态数据给出的同步的数据，计算出对应的目标测距和航迹····

机载光电系统探测数据融合的过程：EOTS采用扫描模式，全景探测飞机四周范围内的所有目标。并且结合飞机姿态和导航信息，将探测到的所有目标信息转化为统一坐标标定，并且给每个目标标注本次扫描探测到的时间；EODAS各个镜头采用凝视模式，全景探测飞机四周范围内所有目标，并且结合飞机导航和姿态信息，将探测到的所有目标转化为统一坐标标定，并且将探测到的目标时间连续标定。

最后火控系统读取这两个传感器系统标定的目标数据，早出两类光电系统对应测角目标，选去相差时间最短的时间标注数据，完成各个目标的跟踪距离计算。

以上的系统工作是循环的。在几十到几百微秒以内完成一轮计算和融合过程，然后进入下一个探测、数据读取、计算周期，如此循环往复。所以光电探测的敏感度、精度是雷达无法企及的·······

radar as the primary target info acquiring method, it also becomes the primiary target for any modern electronic warfare platforms```as a counter measure to EW means, fighter jet needs supplementary means to gain air superiority. optical sensor is one of them for the future`````

PLAAF's new air-to-air BV missle uses dual sensor head````active radar and optical sensor``````

Thanks for this highly accurate explanation!

Worth pointing out that the data process takes consecutive records and there should be a threshold being set against each stream of values respectively. Hence distinctive objects can be identified individually.

Therefore triangulation liked algorithms can be applied to work out the distance and altitude for each individual object under ongoing tracking.

Obviously singular IRST can not achieve this as it has only one aperture.

 

[gambit]

Thanks for this highly accurate explanation!

Worth pointing out that the data process takes consecutive records and there should be a threshold being set against each stream of values respectively. Hence distinctive objects can be identified individually.

Therefore triangulation liked algorithms can be applied to work out the distance and altitude for each individual object under ongoing tracking.

Obviously singular IRST can not achieve this as it has only one aperture.

Nice attempt to help the guy. I give it a C+. But you are on the right track, though.

 

[ozranger]

Nice attempt to help the guy. I give it a C+. But you are on the right track, though.

I was trying to help others but him/her. I was trying to make it easier for others without engineering background to understand what he/she really means.

 

[gambit]

I was trying to help others but him/her. I was trying to make it easier for others without engineering background to understand what he/she really means.

Like I said, you are on the right track. But you may not know it, you pretty much confirmed my argument that a passive sensor alone cannot provide vital target resolution the way radar -- an active sensor -- can.

Keywords from your post: threshold being set against each stream of values

What are those values and where they came from? This is about aviation and specific to avionics.

 

[gambit]

Well I beg to differ, optical sensors like EOTS and EODAS can work out target's speed, heading, altitude and angle```

since you cant read Chinese, I can only try to explain in English

Time's up...You had your chance to explain yourself...Now it is my turn...

The relevant passages are highlighted...

EOTS and EODAS all has the ability to work out speed and aspect angle...these two sensors sending continuous target data to the fire-control system, and the fire-control system combines its won platform data, like its speed, heading, altitude and angle, so the fire-control system will calculate these data, to get a synchronous data of the target.

EOTS starts scan mode to overview the area, find any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target after each scan, and between two scans, there is a time difference + changes of target's flying posture, so the speed can be worked out

each EODAS lense uses gazing mode, overview the area, gaze up on any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target too, and the target coordination labling is continous, so there is the track​

See them?

But just in case you missed, the operative words are, by your -- not mine -- translation: OWN PLATFORM.

It means the fire control computer (FCC) is the source of target resolutions, not the passive sensors. The FCC continuously receives 'platform' data, meaning aircraft FLIGHT DATA from the inertial navigation system (INS). Data such as aircraft airspeed, altitude, and heading. Once the target's visual representation is focused, the FCC then from its own data, calculate the DIFFERENCES of movement between the image from the aircraft's flight data. The FCC can use radar information but radar is optional because the radar can be in standby mode (non-transmitting). But INS data is continuous. Look at your own words: 'flying posture'.

In other words, what I said earlier is correct that the passive sensor cannot calculate any target resolution but can only provides focused image. Target resolutions are actually DERIVED from a secondary source: the aircraft's own flight data (INS).

Radar do not work this way. The EM medium interacts with the target. Upon contact, the EM signal is altered at least in phase and amplification. The reflected signals can be used by any other radar receiver in the area without passing thru the original source transmitter. Passive sensor images cannot do that. Once you processed that image and derived any target resolutions, YOU have to pass that info to other audience.

Looks like I understand the J-20's subsystems better than you do. And I do not read Chinese.

 

[SME11B]

I've been waiting for you to clean this shit up, as everyone else. DO YOUR JOB.



Are we seeing a trend here? Clearly, you've not been liked anywhere you go and you blame the international mods for doing their jobs? Wait until you go troll on a Chinese speaking forum with Chinese mods or even a Russian forum. I'm sure they won't be as nice.. lmao

Then you won't get information that certain parties deem sensitive.

Far more intellectuals are on SDF, that's why you won't dare to troll over there. You are just a coward Gambit.

Cowards are those who try to silence others because they can't come up with a good argument. It shouldn't matter anyway this shouldn't be a place with an agenda it's just people talking about J-20 good or bad.

 

[rcrmj]

some people arguing for the sake of it`````I'm saying optical sensors are great supplementary means in the case radar cannot work in a tipical situation, and yet he keeps playing with the words and saying radar works more efficiently on providing target infos than optical sensors````

the thing he doesnt know is that, the optical sensor system can do the circile (scan, calculation and fuse) thousands of times in a second, so the sensor system can work out very detailed and more importantly accurate target info for tactical purposes. `````` but again, he insists on lenses alone cannot do the image matching, coordination labling and data calculation``````what he is missing is that EODAS and EOTS is not a system of few lenses, it also includes back-end processors and such````well, if you want to play the words, that I can also safely to say that radar alone cant provide detailed target info, as it only has plate, transmitor and reciever`````

5th gen platform is a fusion, it fuses all kinds of infomation from various sensors and intelligence to achieve optimum situation awareness.

Thanks for this highly accurate explanation!

Worth pointing out that the data process takes consecutive records and there should be a threshold being set against each stream of values respectively. Hence distinctive objects can be identified individually.

Therefore triangulation liked algorithms can be applied to work out the distance and altitude for each individual object under ongoing tracking.

Obviously singular IRST can not achieve this as it has only one aperture.

thank you, "triangulation liked algorithms can be applied to work out the distance and altitude for each individual object under ongoing tracking"````this is well put

 

[gambit]

some people arguing for the sake of it`````I'm saying optical sensors are great supplementary means in the case radar cannot work in a tipical situation, and yet he keeps playing with the words and saying radar works more efficiently on providing target infos than optical sensors````

the thing he doesnt know is that, the optical sensor system can do the circile (scan, calculation and fuse) thousands of times in a second, so the sensor system can work out very detailed and more importantly accurate target info for tactical purposes. `````` but again, he insists on lenses alone cannot do the image matching, coordination labling and data calculation``````what he is missing is that EODAS and EOTS is not a system of few lenses, it also includes back-end processors and such````well, if you want to play the words, that I can also safely to say that radar alone cant provide detailed target info, as it only has plate, transmitor and reciever`````

5th gen platform is a fusion, it fuses all kinds of infomation from various sensors and intelligence to achieve optimum situation awareness.

No...It is YOU who are now playing with words. I explained the operations based upon YOUR translation and YOUR translation includes the fire control computer (FCC) and inertial navigation system (INS) as collator and reference flight data BEFORE target data can be derived.

 

[lcloo]

I dont really post pictures on forum often, any Chinese member can tell me how to upload images on this site?

Look for a box that said "Upload a Files". It should be just next to the "Post Reply" box.
Press it and go to where the photo is kept.
Select the photo you want to post. The rest is easy.

 

[rcrmj]

I always download Photo to my hard-disc in Drive C or E. Nowaday people also use cloud/ One Drive. You have to know where you keep your photo, is it in your computer or in the cloud?

i kept on my computer

I remember we have to upload the picture to a hosting website, and then to paste the URL on here?

I will give it try```

the stealth fighter's RCS from different angle

this is how target's flight path appears on the screen

this is how the system detecting stealth target

there is a myth among fans, that stealth fighter cannot be detected by air-born radars, and due to its 0.001RCS, the detection range is too close to apply any aggressive or active tactics, so there is no initiative````but the reality is not quite right on that assumption````as the maps show, the stealth fighter's RCS varies with big deal, its rear and backside's RCS is no smaller than regular 4th gen fighters (well, to be precisely is smaller, but with no significance)````

therefore, with a complete 5th gen infomation centric warfare system, stealth target can be detected, and can be dealt with with aggressive or active tactics, but this system needs huge amount of resources and technological readiness to develop and maintain````so far, not sure about Russia, only China and U.S has made significent progresses on this new battle system``````

or to put this in an easy way to understand, that is you need 3 units of sensor, fighter and command platforms to deal with normal air threat, but you need 15 units of them in order to deal with 5th gen fighter````the cost and technological requirement is just too dearly to other countries````secure data link and resillient EW capability is the fundation of this new system````lets look around, who has these?

 

[samsara]

i kept on my computer

I remember we have to upload the picture to a hosting website, and then to paste the URL on here?

Since you keep the file in your computer, alternatively you can just UPLOAD the pictures into the PDF's own server. Look at the middle radio button of "Upload a File", choose that then select the files to upload then finally select to Full Image to show them at full size in your post. That's what I do.

Note: keep the filename rather short when upload a file to PDF file server, too long the filename may cause rejection.

 

[rcrmj]

here are the maps of optical sensors namely EODAS and EOTS

from above 5 maps, we can work out a simple tactic in dealing with stealth target

various sensors and AWACs spreading along the battle theatre (not randomly but with formation and plan)
our stealth fighter's radar is off, acquiring data from various platforms via data links````once the stealth target's signal is detected, labled and tracked, the stealth fighter will command its optical sensors to scan and gaze upon the target```at this point the stealth target still has no idea that it is been gazed on by a fighter jet`````

when all the condition is ready, our stealth fighter launches long range missiles, each missile programmed with different flight route in order to maximize killing possibility````then the end``

well, this senario is ideal, as the real air battle is much much more complicated than this!``````but all I'm saying is that stealth fighter is not some kind of mythical god sent tech that cannt be dealt with. The most difficult part is to how to develop a state of art infomation centric battle system`````without such system, give you hundreds of 5th gen stealth fighter, still wont make too much difference`````maybe the difference is more to your own old fashioned battle system than to your opponents`````

 

[Deino]

In order to keep the regular J-20 news thread clean from the more technical stuff, please continue here.

Deino

 

[Figaro]

Here is perhaps the most comprehensive RCS study done by Westerners on the J-20 ... by Dr. Karlo Kopp. It is far from perfect and the models he uses certainly has large limitations. But it gives you a basic idea of J-20 stealth effectiveness and is far better than the "experts" cited by Business Insider and the National Internet. As for @SME11B, I can assure you that Dr. Kopp is not part of the "CCP state propaganda."

http://www.ausairpower.net/APA-2011-03.html