Chapter 636 A relatively complex algorithm

The moment he heard Chang Haonan's affirmative answer, Guo Liqiang's originally tense expression suddenly relaxed, and he became visibly relaxed.

After all, this project is definitely a big job. If it can be implemented, it will be like a huge wealth to the missile department of their Aerospace Technology Research Institute.

It is estimated that he will no longer have to worry about project issues until he retires.

"But Mr. Chang, this is just an idea for now. I did some preliminary research on the implementation level a few days ago when I was waiting for the reply from the Science and Technology Commission, but... the time was too short and there was no substantial progress."

When he said this, he realized that he had already broken out in a layer of sweat after just ten minutes of waiting for the results.

It is true that there is still a bit of an "autumn tiger" atmosphere in Sichuan Province in early September, but this room is located in the shade and has good ventilation, so it is obviously not completely hot.

Chang Haonan nodded slightly, then pulled the documents that had just been pushed in front of him again and started to read them carefully.

As Guo Liqiang just said, he really didn’t write much on the positioning and missile control algorithms. After all, these two parts have already involved theoretical fields, and it is impossible for ordinary people to get any results just by thinking about it.

But he still made some useful designs for the use of this multi-source network detection system.

For example, the two "detection bombs" fired by the aircraft carrier platform should choose the ballistics as different as possible. Together with the carrier aircraft itself, they should approach the general location of the target from multiple angles to capture effective signal data with the largest possible length to achieve Precise detection of targets across the entire range.

However, this also means that the straight, high-throwing and diving trajectory of traditional air-to-air missiles is no longer applicable. It is necessary to refer to some ballistic characteristics of ground-attack missiles to meet tactical requirements.

In addition, even with a directional data transmission system, this aircraft and two bombs are still three independent individuals, and they are still in rapid relative motion. How to capture the radar signals captured by each other, which may not be continuous? "Combining" or "splicing" together is also a big problem...

"Not bad……"

Chang Haonan's eyes quickly passed over the words on the page, while he secretly affirmed the content in his heart.

In just a few days, Guo Liqiang has grasped two key issues.

Before, he and the other party could only be considered acquaintances, but he didn't expect that he actually had some ink...

For Chang Haonan, reading a good technical document feels no less like reading a masterpiece handed down from ancient times to literary geeks in ancient times.

So I can't help but feel a little excited, especially when turning pages, the movements are much bigger.

However, just when he was about to see what was going to happen next...

wow-

Only to find that the next page was blank.

Obviously, this report is a mess.

Chang Haonan had almost the same emotion as Professor Roger Elinor:

"Why is it gone here?"

But in the end I still held back.

For a study, raising questions is at least as important as solving them.

Guo Liqiang is already quite good at writing this.

After all, if the following content could be filled in, there would be no need for the other party to come all the way to find him.

……

After calming down a little, Chang Haonan took out a pen from the pen holder:

"I just briefly reviewed the working logic of the entire machine bomb network detection system."

Guo Liqiang had never worked seriously with Chang Haonan in the past, but he could see that this was the boss's gesture of preparing to exert force, so he immediately moved the stool under his butt slightly closer.

"First, the airborne passive detection system is used to conduct early warning detection and rough positioning of enemy ultra-long-distance targets or low-detectability targets, and provide initial information for the aircraft to launch missiles."

Chang Haonan's painting skills have improved a lot in the past two years, but he is still at the level of simple drawing plus, so he simply drew a frame instead:

"Then, a carrier aircraft is used to jointly form a network with more than two active and passive composite guided air-to-air missiles to carry out high-precision passive detection. In this step, I think it is necessary to use time difference positioning technology and filtering algorithms to obtain the precise position information of the target for long-range air-to-air missiles. The missile provides mid-course guidance information.”

"Eh?"

Guo Liqiang's expression froze:

"Time difference positioning method?"

The reason why he was so shocked was not because of how new the algorithm was.

On the contrary, it's because it's too stale.

The so-called time difference positioning (TDOA) is to use the arrival time difference of electromagnetic radiation signals received at multiple points to determine the orientation and distance of the radiation source.

In fact, on the JH-7, this logic is used for passive positioning.

It's just that the "multiple points" above are the two pods on the left and right, which are very close to each other, so the error is very large.

Now the multi-point is an aircraft and two missiles, with a distance of tens or hundreds of kilometers, so the positioning accuracy has naturally improved.

Therefore, this idea is too direct, and it even makes Guo Liqiang feel that Chang Haonan should not have come up with it.

"Yeah, time difference positioning method."

Chang Haonan next to him was a little confused by his reaction. He was stunned for a moment before nodding:

"This should be the most appropriate algorithm. Guo Gong... must have heard of it..."

At the end of the sentence, there was even a somewhat uncertain tone of questioning.

Obviously, there is still half a sentence left to ask——

Is this something that should surprise you?

Guo Liqiang also realized that his reaction was a bit excessive, and immediately explained:

"Hey... after all, it's about control. Of course I've heard of TDOA, but I always felt that Mr. Chang would come up with a more clever algorithm..."

Chang Haonan couldn't help but laugh when he heard the other party's thoughts:

"Algorithms are just a mathematical tool. It doesn't matter whether it's high or low, as long as it's easy to use. If you just create a new algorithm with a higher complexity in unnecessary places just to show off your skills, it will complicate simple problems. It does not conform to the principles of our technical staff."

"makes sense……"

Guo Liqiang nodded, obviously agreeing with Chang Haonan's statement.

The upper body that had just leaned forward also leaned back on the chair.

I even intentionally or unintentionally ignored the details of Chang Haonan calling this problem a "simple problem"...

However, just as he was relieved, Chang Haonan changed the subject again:

"However, although the principle of multi-station time-difference passive positioning is very simple, when it comes to our problem, it still requires some skills to use three positioning stations in relative motion to accurately determine the position of the target radiation source."

"In the past, on electronic warfare aircraft, because the two pods were always relatively stationary, and there was a data bus connection between the pod and the aircraft, a special computer could be used to perform calculations, so the traditional Newtonian method was used directly. Iterative methods can also be solved.”

"But the current machine-munition network detection requires a lot of calculations, and the data transmission rate between each other is also slow. We definitely can't use the old method. Otherwise, by the time the target position is calculated, the missile will reach its maximum range. Already..."

Guo Liqiang's upper body, which he had just leaned back, sat upright again:

"Then what Mr. Chang means is..."

“Multi-station time difference positioning is essentially about solving a set of strongly nonlinear partial differential equations.”

Chang Haonan adjusted his sitting posture slightly:

"So here, it is necessary to develop a relatively complex algorithm..."