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Research Papers: Pakistani Aerospace Technologies

Bilal.

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There are way too many papers for me to post so I am just posting titles. Summary: PAF's biggest (based on research output) project seems to be an X-band fighter AESA radar.

This is mostly gibberish to me because I don't know this stuff. Perhaps @Signalian can comment on these papers if there's anything to comment on how serious this stuff actually looks.

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This is probably work for Azm MALE (not AESA radar) even though they've used an MQ-9 CAD model for some reason.
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@Bilal Khan (Quwa) contrary to what many of us were thinking, this does not look like just a systems integration exercise. There seems to be work on the actual T/R modules too.
GaN based, 15W per module😍
 

JamD

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I read the first paper about design of AESA radar.

Frankly, PDF members would want a 1000 km looking radar tracking 100 targets and engaging 50 of those with BUR (Beyond Universe Range) Missiles. Same with S-400, that its capable of detecting anything at 400 km radius or even more, well radar doesn't work like this. Every radar has short comings, no matter how powerful it is. I still laugh at one Indian members comment about S-400," if it flies, it dies", sure mate, S-400 is God made system right.

Anyways, back to paper, radar requirements such as search, track, high target density, environment and system integration giving performance out as peak transmit power, antenna gain, and Noise Figure (NF) including processing (data) throughput, mission software, diagnostics software, and signal processing software. These are fundamentals. Any moving platform (a/c) requires additional air-to air and air-to-surface radar functions or modes. The main features to look in radar are Signal to Noise Ratio (SNR), minimum
detection rage, transmit and receive peak power, and antenna gain. All these are calculated theoretically first and then a hardware(antenna leading to radar) is built around them. As we move on further for designing a modern radar, more requirements come up like Terrain collision avoidance, Synthetic Aperture Radar (SAR), and Doppler Beam Sharpening (DBS).

Okay then they talk about fighter air to air mode and air to surface mode. They do analysis of trade offs using size, power, weight etc for selection of appropriate operating frequency, waveform, radar coverage, receiver operating characteristics, search design, tracking architectures, and target classifiers in the radar design. Jumping onto Radar Open Structure Architecture (ROSA) is based on modular Commercial-Off-the-Shelf (COTS) components. This ROSA is a basic system referenced from another article. They discuss T/R modules and other restrictions on radars which is again referenced from other papers and then jump from hardware to radar control computer (RCC), radar operating software (ROS), and radar task scheduler (RTS). Then talk about already existing AESA radars.

There is nothing PROPOSED in this paper. They are merely discussing what is already out there. Radar is a technical subject, at least, they should have proposed a new technical design of just one module of radar. No equations for calculations to back up that proposal. They talk about figure 11 (referenced form article 10) for a Multi- Function Phased Array Radar (MFAR) which they have already referenced from article 12. If they propose a design, they have to back it up with logic and technical analysis of calculations and why their proposal is feasible for modern systems or more importantly which short coming they are addressing. This is why literature review is conducted - to understand what is done and currently being done. Then find out what lacks where or which problem can be addressed to improve it further. Can you find anything like that in tis article ?

Have you read the conclusion ? Don't you find it childish. They are telling what needs to be done, fair enough, but what have these research students done themselves? Compiled information from 49 references and published it mixing them altogether. Its like summarizing all those 49 references. Are they sure this is research.

Do you know what is really disappointing ? This is a 2019 article. There just 4 references from 2016, 2 from 2017 and just 1 from 2018. This a disaster. It means there is no exposure of knowledge and information or recent advancements from 2016 onwards till 2019 which should have made the bulk of references. Out of 49, half of references should have been 2015 to 2019 at least.

There are no calculations here leading to a conclusion which is basic core of research. Well i mean, not just calculations, but ensuring that research is taken ahead even by 0.000001% overall to impact globally. If I would use this article as reference then it would just be referenced to tell readers that ROSA exists already and then moving ahead towards my newer proposed design or improved module based on calculations I conducted.

If i presented such a paper to my supervisor, he would throw it back at my face and tell me to get lost. Just 45-50 references would be for literature review of article and ending up around 150 references with at least 50 references used to support the proposed design.
First of all thank you for taking the time to read and explain the paper to us.

Agreed on all of your points on writing papers.

I am not surprised that the paper was substandard. Since I am looking at papers published in Pakistani conferences they seem to follow the following distribution:
10% are good papers that are published in Pakistan because the authors couldn't afford to go abroad for conferences
90% are bad papers that people could only get accepted at Pakistani conferences.

With this in mind I make an effort to sift some of the garbage out. However, since I am unable to understand the details in this field I think my brain just gave up and I posted the papers with the fanciest titles.

The question is were there any papers that had some value or demonstrated some actual work being done? Maybe the design of T/R module paper. See the thing is that I cant tell if it's an undergraduate FYP or a serious design meant for a serious thing after some iterations.
 

JamD

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Paper of limited or no research value but full of data on the JF-17 - this is as official of data that we can hope for:
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RD-93 Data:
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ROC: Rate of Climb
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Some inconsistency here - Cmalpha is negative and yet the aircraft is stated as being unstable. I guess the word is being used "loosely". The aircraft is almost unstable at whatever condition this table is for.
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  • PerformanceAndStabilityAnalysisOfAHighSpeedJetUsingMultiDisciplinaryApproach.pdf
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JamD

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Some interesting work. The application is interesting but I feel the methodolgy is not. ML has become the poor man's research tool. Anybody can run codes and get nice looking results eventually. A better work on this topic would have done some kind of intelligent optimization instead of viewing everything on the planet as a ML problem. In the author's defense, using ML for everything is in fashion these days. It doesn't hurt that its impossible to question ML results and thus extremely easy to publish results. This is why you have more ML papers than you can grasp your head around. Rant about ML over lol.
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  • reinforcement-learning-based-radar-evasive-path-planning-a-comparative-analysis.pdf
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Mar 8, 2021
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Some interesting work. The application is interesting but I feel the methodolgy is not. ML has become the poor man's research tool. Anybody can run codes and get nice looking results eventually. A better work on this topic would have done some kind of intelligent optimization instead of viewing everything on the planet as a ML problem. In the author's defense, using ML for everything is in fashion these days. It doesn't hurt that its impossible to question ML results and thus extremely easy to publish results. This is why you have more ML papers than you can grasp your head around. Rant about ML over lol.
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Do you think that after military started many projects ,more research papers are emerging.Quality of research papers will then surely improve with time if that's the case.
 

JamD

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Structural analysis of JF-17 wing
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Gives some info, also says g limit is 7g based on FEM. I bet this is block 1 or something.

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Work on high-speed-target drone:
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  • Static_Structural_Analysis_of_Fighter_Aircrafts_Wing_Spars.pdf
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  • HighSpeedDrone.pdf
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JamD

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Do you think that after military started many projects ,more research papers are emerging.Quality of research papers will then surely improve with time if that's the case.
Definitely. R&D takes decades of consistent backing. However, we need to work on a sustainably growing and robust economy because we cannot expect our shrinking defense budget (in real terms) due to our shrinking economy to fund R&D.


The above is probably just a generic design since PAC's HSTT looks different:
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