The Military-industrial Scientific Research System of the Academic Master Chapter 825

Chapter 825 Testing, target feature extraction

Of course, using ballistic missiles to counter aircraft carriers is definitely not that simple. It can be solved by developing a target classification algorithm.

First of all, the prerequisite for “target classification” is to detect the target.

But how to enable ballistic missiles to overcome black obstacles and use radar normally during re-entry into the atmosphere is a huge problem...

Reducing the reentry speed to less than 5 times the speed of sound can avoid the occurrence of black barriers from the source. However, low-speed ballistic targets are the easiest targets for the air defense system, which defeats the original purpose of using ballistic missiles to fight ships.

If you wait until you have passed the black barrier area before turning on the radar, the reaction time will be too short and it will not be enough for the missile to adjust its attitude.

Secondly, to find the location of the aircraft carrier battle group in the vast ocean before the strike, a complete global ocean monitoring system is needed.

At this moment, China has just launched its first land-based remote sensing satellite.

The second and third satellites are Ziyu-201 and 02 that will be launched soon—

This is also the original reason why Chang Haonan rushed out to conduct technical testing before the Spring Festival.

As for ocean remote sensing satellites…

Sorry, not even one.

In short, at least in 2000, we could only think about developing anti-ship ballistic missiles—

Most people wouldn't even dare to think about it.

On the contrary, Wang Xiaomo's idea is more realistic.

In particular, Chang Haonan has previously considered designing an anti-submarine patrol aircraft based on the C808 platform that has a comfort level and a range that exceeds or is no less than that of the P3C.

In the current context where the main tone of the confrontation is to fight without defeat, the importance of this equipment is not less important than conventional main battle equipment such as tactical aircraft, if not more important.

Thinking of this, Chang Haonan immediately turned to look at Liang Shaoxiu, who was a little distracted from radar-related topics:

“Gong Liang, our Air Police 200 has not done any hardware shielding for low-altitude targets, right?”

Since the main function of early warning aircraft when developing is air detection, there are many models that directly limit the longitudinal depression angle of electromagnetic waves on the hardware, in order to solve the interference caused by ground echoes in the simplest and crudest way.

What's more, a shielding layer will be designed under the antenna to directly block the downward electromagnetic waves at large depression angles.

Chang Haonan definitely didn't have this thing when he made the plan, but there is no guarantee that it will be added in the past two years.

“No, I just limited the downward angle in the radar background program”

Liang Shaoxiu replied:

“And because it is still a prototype, this restriction can be lifted through a special command. If you have a new target recognition program, Mr. Chang, just modify the software part here.”

Since pilots and ground crew are not professional aircraft designers, when the mass-produced aircraft is delivered to them, in order to prevent anyone from messing with it, the software programs are locked, leaving only some preset input and output ports. .

However, prototypes or technical verification opportunities have a status similar to "developer mode", allowing engineers to make modifications more conveniently.

“Don't worry, there is no need to make major changes to the current procedures.”

Chang Haonan looked back at the staff who followed him.

　　The latter understood immediately and took over a password box that he carried with him.

After opening it, there are several hard drives inside.

“I have encapsulated the target feature extraction and analysis functions into a module, which can be plugged into the existing data processing code.”

Having said that, the operating computer on the early warning aircraft is not a home computer after all. Just make an installation file in .msi format and wait for it to be completed automatically.

WindowsXP, which was widely used in military terminals in later generations, was still a trendy thing that could only be installed on the latest PCs.

It has extremely high hardware requirements and is also unstable.

It's almost the same as win11 in 2023.

And it hasn't been officially released yet.

So, it took Chang Haonan nearly a week to completely complete the program update and necessary ground testing.

It even took longer than it took him to write the program before.

Of course, Liang Shaoxiu and the others are not idle these days either.

Instead, he helped coordinate with the naval leaders and borrowed a batch of false targets for training.

It's not something fancy like a self-propelled decoy.

Instead, it is a simple method to install different styles of models or corner reflectors on the buoys.

Used to low-cost simulate targets of various sizes from sampans to destroyers in non-live-fire training.

It is a method that the army had to endure during the early years and had no other options.

The advantage is that it can be deployed using a transport boat or tugboat, and it can be recycled without damage after use.

But later I found out that the effect was actually quite good.

However, because it is a buoy, it cannot be deployed in places such as the high seas and oceans. It can only play a role in relatively shallow locations.

The last day before New Year's Eve.

"Mr. Chang, comrades from the North Sea Fleet sent back a message saying that they have set up all the 35 preset false targets. In addition, the three warships 107, 110, and 519 that are training in the nearby waters will also cooperate with us. Real ship target, compared with the signal characteristics of the corner reflector.”

Liang Shaoxiu hung up the phone and said to Chang Haonan who was not far away.

The latter was currently looking out of the floor-to-ceiling window of the tower, watching Air Police 200 drive from the apron onto the taxiway:

“Notify Unit 20001 to prepare for takeoff.”

If it makes sense, then Chang Haonan, as the deputy chief designer, Liang Shaoxiu should be regarded as his leader in the Air Police 200 project.

It's just that the content of this test has no direct relationship with the early warning aircraft itself, and the two parties are closer to cooperation.

The reason why it is carried out under the framework of Air Police 200 is simply for convenience.

Moreover, Liang Shaoxiu has actually been learning from Chang Haonan since the time he solved the problem of ice on the wings of the Y-8 platform at the end of 1996.

Like Lin Shikuan from Institute 601 back then, he was considered a half-disciple brought out by Chang Haonan.

Hence the strange scene in front of us where the chief division reported the situation to the deputy chief division, and then the deputy chief division issued instructions to the chief division.

A few minutes later, Air Marshal 200 rose into the sky from the end of the runway, dragging four lines of faint black smoke, and gradually disappeared from everyone's sight.

"Mr. Chang, Comrade Shaoxiu has complained to me a lot before, saying that the performance of the turboprop 6 is still a bit lagging behind..." Wang Xiaomo looked at the black wake that had not completely dissipated in mid-air, and said to Chang Haonan next to him:

“I heard that when your aviation power group was established last year, you mentioned a development plan for a turboprop engine?”

Obviously, this is implying...or indicating that we want a turboprop engine with better performance.

In other words, a flying platform with better performance.

If Liang Shaoxiu had said this, it would have been difficult to determine the balance between suggestions and dissatisfaction.

But Wang Xiaomo has nothing to do with the aviation system, so he has no concerns in this regard.

“Indeed there is.”

Chang Haonan nodded:

“But the design power of that machine is only 1,600kw. It is planned to be used for 10-ton helicopters or 20-ton turboprops like the Y-7, which is not the same level.”

“As for the 4,000kW-level turboprops...I'm not talking about those imaginary ones. They really don't have a high priority at the moment.”

“We actually have R&D capabilities here, but the number of technical personnel is still too small, and we can't take care of too many models at the same time. We can only work on the most urgently needed ones first…”

When the Air Police 200 landed back, it was almost three hours later.

According to Chang Haonan's test requirements, the aircraft must conduct four rounds of searches for targets from different angles, that is, two zigzag routes that are generally perpendicular to each other.

For the Air Police 200, which has a somewhat limited range, this is even the longest flight since the prototype's first flight...

While the ground crew rushed over to perform maintenance on the aircraft, the engineer on board had also taken down the recorded radar data and handed it to Chang Haonan.

Hence, it is naturally impossible for supercomputing to be used here in Xingcheng Base.

Fortunately, if you just want to check the results or simply adjust parameters, you can use an ordinary computer.

But if the algorithm needs to be improved in the future, we will have to go back to the capital to do it again.

“We marked targets 1-39 in the order in which we first completed the search.”

The radar operator responsible for following the test flight is a naval lieutenant colonel named Su Changyun. At this time, he is sitting behind Chang Haonan and Wang Xiaomo, introducing the details of the flight just now:

“Originally, there were 35 false targets plus 3 ships, a total of 38, but we found an illegal fishing boat in the target waters, so there was one more.”

“Then this fishing boat ended up...”

Although this matter had nothing to do with the test, Chang Haonan still couldn't restrain his curiosity.

“We contacted the 110th Dalian Ship through the North Sea Fleet Command, and finally caught them and found out that they were a group of people stowaway.”

“Okay…it's pretty good.”

Wang Xiaomo next to him showed a helpless smile:

“Being able to become the first combat result under the command of an early warning aircraft in the history of our country is, to a certain extent, recorded in the annals of history…”

“And it also provides us with the typical signal characteristics of a fishing boat.”

Chang Haonan added next to him:

“In the future, you can add it to the white list of anti-ship weapons, or at least set the aiming coefficient to the end to avoid accidental hits...”

Other people here naturally don't know about Xiongfeng 3's fishing boats, so they just assume that he is preparing for a rainy day.

After a brief interlude, everyone returned their attention to the radar data.

There are two sets of data in total, one is original and the other is processed by the recognition algorithm.

In addition to being used for comparison, the difference between the two sets of data itself can also be used as a basis for judging the nature of the target -

Since the radar display is not specially set, the result output to it is a dot.

But in the background running log, the difference can be clearly seen.

The most intuitive thing is that the latter has richer or clearer data levels than the former.

“Two targets 1 and 2, four directions, each with two sets of data. The first set was directly hidden in the sea clutter and was not seen. The second set was seen but very faint. It should be a simulated periscope..."

"The RCS of numbers 3 to 16 are quite large, but it was revealed in the second set of data that they are completely different from the signal characteristics of the three targets 36, 37, and 38... Considering the difference in quantity, The dozen in front should be different large corner reflectors, and the last three should be the three real warships..."

“17 and 18, there is almost no difference in the signal characteristics detected in the four directions. They should be small corner reflectors, used to simulate speed boats or patrol boats..."

Every time Chang Haonan finished speaking, Su Changyun compared it with the "standard answer" sent by the fleet.

In the end, except for the misjudgment of "reef" and "small boat", everything else was correct.

For a first test, the results are pretty good —

After all, the radar and computer won't know what humans define as a target, it's only responsible for finding the difference.

As for the inductive analysis of signals with different characteristics, it needs to be calibrated slowly later.

For example, the targets with characteristics A are large and medium-sized surface ships, the targets with characteristics B are ordinary bulk carriers, and the targets with characteristics C are container ships...

In fact, this is the fundamental purpose of Chang Haonan running over for testing.

Although the situation of early warning aircraft cannot be directly transferred to remote sensing satellites, the methods of feature extraction and selection of calibration anchor points are the same.

“Although it's not perfect yet, it has great potential.”

After reading all the results, Wang Xiaomo came to a conclusion almost immediately:

“Especially in terms of decoy identification, it is almost accurate at a glance, but unfortunately the amount of storage and calculation required is too large, so it is not easy to put it on the radar of a fighter jet.”

“That's not necessarily the case.”

Chang Haonan was already adjusting parameters and calibration methods, but he still stopped what he was doing after hearing what the other party said:

“The main function of fighter radar is air search. The background is relatively clean and the target features are more monotonous. I can write a simplified version for use by 1473 and 1493 series radars..."

Wang Xiaomo just said it casually, but he didn't expect Chang Haonan to actually come up with a feasible plan.

He stood up suddenly:

“Then I'll contact the 14th institute. It just so happens that these types of radars, oh, and 346, haven't been finalized yet. We can take this opportunity to work together...”

(End of this chapter)

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