Chapter 1379: Patrolling the Sky

The hot wind from the Gobi Desert carried gravel and hit the glass windows of the cafeteria. Guo Lin took off his glasses and wiped the lenses. The condensed oil on the stainless steel plate reflected the swaying incandescent light on the ceiling.

He heard the sound of a dining chair being dragged beside him.

It was Xing Muchun who was walking towards this side carrying an enamel pot.

The celebration banquet had ended and most people had left long ago, leaving only a few of them who had been discussing the issue and still felt a little reluctant to leave.

"Actually."

Chang Haonan, who was sitting opposite him, saw Xing Muchun sitting down again and spoke again:

"When I saw the leader off on the plane, I noticed that they were also concerned about hypersonic missile defense, or at least the issue of early warning... Of course, this is no secret, otherwise the radar confrontation part would not have been temporarily added to this test."

Xing Muchun sat back in his chair and took a sip of tea:

"Yeah... Although the Americans suffered a setback with the X51A, I think HTV2, the Falcon project, is pretty decent. Plus, the gliding aircraft is still not as technically difficult as the air-breathing aircraft. So even though we won this time, I estimate that it won't be long before the other side gets similar equipment, and we'll definitely have to worry about defense issues by then."

If both sides have a weapon and neither can intercept it, then a deterrent balance similar to nuclear weapons will be formed.

The party that first obtains this ability obviously does not want to see this situation.

Chang Haonan was picking out the last few pieces of meat without bones from the sweet and sour fish. Hearing this, he curled his lips and thought, maybe not.

But what the other party said was true, so he didn't pay attention to the details:

"In short, the test results this time have shown that with the current level of technology, even if conventional early warning radars are pushed to their limit, it is difficult to provide sufficient warning time... let alone organize firepower interception."

Having said this, he put down his chopsticks, stood up, put on his coat and prepared to leave:

"So I think there is no need to arrange for the Maodao radar station to counter the two test launches in August and September... Simply repeating it multiple times will not produce different results, but will affect the morale of the comrades participating in the test."

For a radar station, the feeling of powerlessness brought about by frequently facing an opponent that it is completely unable to fight against is very serious.

This is completely different from those goals that can be achieved or at least have hope of being achieved with hard work.

Guo Lin nodded immediately:

"I feel the same way..."

In fact, not to mention the Maodao radar station, even he couldn't help feeling a little frustrated.

But he stopped talking halfway.

He heard some hidden meaning in the other party's words.

There were no confrontations planned for the test launches in August and September. Does that mean the test launches will continue in the future?

As expected, Chang Haonan said as he walked out of the cafeteria:

"Wait until the end of this year or early next year to try out the new early warning principle..."

Guo Lin had been traveling for half the night and had just finished his meal, so he felt his eyelids were a little droopy.

As a result, I woke up immediately after hearing these words:

"How about... we go to the conference room to discuss it in detail?"

……

This time, Guo Lin came with doubts.

So he brought a lot of technical and operational information,

"We analyzed the records of the X51A test flight in the western Pacific last year. The Doppler shift in the original data caused a 47D imaging distortion rate of more than %. Fortunately, the trajectory was stable and there was no blackout problem. Relying on the multi-base station deployment method and the characteristic parameters we have accumulated, we can still achieve stable tracking."

His pen tip poked at a violently trembling peak on the copy paper:

"Now we are facing a speed more than twice that. Even if we continue to use multi-base deployment, the situation is not optimistic. Considering other interference factors, is it too radical to expect the problem to be solved in half a year?"

It is now mid-June, and as Chang Haonan and Liang Yangang said just now, two more launches will be scheduled before the end of the year.

That would take at most half a year.

“It’s really too much to solve the problem in half a year.”

Chang Haonan raised his hand and pressed it down, making a calm gesture:

"My plan is to transform the existing equipment before the end of the year to verify whether the new technology is feasible. If it is feasible, I will consider turning it into a formal project next year... As for actually passing the acceptance and putting it into use, I'm afraid it will take more than two or three years..."

Guo Lin opened his mouth, but for a moment he didn't know where to start.

There is indeed a lot of information in this sentence.

If even Chang Haonan says that a project cannot be completed in the next two or three years, it means that the scale is probably far beyond ordinary people's imagination.

However, Guo Lin found it hard to imagine that, based on China's current construction efficiency, even a radar of the size of 7010 might not be worth the other party's words.

But after thinking it over again and again, he decided to discuss another more specific part first:

"So, you already have an idea?"

Chang Haonan touched the stubble on his temples that he hadn't had time to clean:

"Actually, this isn't a recent idea... I thought of it a long time ago, but I thought it was too exaggerated at the time, so I never really talked about it. It wasn't until recently that I felt that the objective conditions were relatively sufficient..."

To be honest, the fact that the 14th Institute of China Electronics Technology Group Corporation built a medium-sized fixed phased array radar in less than half a year was indeed beyond his expectations, even taking into account the infrastructure left over from the 7010 Project.

This brought back to life a plan that he had originally forgotten.

Chang Haonan turned on his computer, then turned the screen to face Guo Lin and Xing Muchun:

"Last year's detection of X51A essentially used an ultra-high-speed moving target detection method based on matched Fourier transform. By searching for the target speed and initial distance, the matching process with the echo signal was achieved, thereby eliminating the influence of high-order terms in the echo phase on the coherent accumulation... However, due to equipment and construction period limitations, the cross-distance unit movement correction of the echo envelope was not achieved."

Xing Muchun had hardly any experience working in the radar field, so he was basically just listening for fun.

But Guo Lin thought about it thoughtfully:

"But we have already applied the Keystone transformation?"

Chang Haonan shook his head:

"Strictly speaking, there is no special implementation of envelope movement correction."

He rolled the mouse wheel and switched the document on the screen to a page full of calculation formulas:

"The Keystone transformation method is aimed at weak targets that accumulate over a long period of time, but hypersonic weapons cannot give radars enough time to accumulate, so poor results are inevitable."

Guo Lin had a "are you kidding me" expression on his face:

"But this is determined by the characteristics of hypersonic speed... How can we get enough accumulation time?"

"So I came up with a new transformation method."

Chang Haonan pointed to the lower half of the page and said:

“The signals captured by multiple antennas can be accumulated to meet the cumulative time condition.”

Guo Lin narrowed his eyes slightly, and this time he did not speak immediately. Instead, he stared at the computer screen for a while:

"But it's okay for dual-base radars. It's actually difficult for multi-base radars to provide sufficient synchronization. The cumulative error will still be too large to be acceptable..."

Chang Haonan tapped the table with the pen cap, his tone full of excitement:

“So I’m talking about multiple antennas, not multiple radars.”

After a pause, he continued:

"In the echo envelope of a hypersonic moving target, the distance movement is usually the main contributor to the envelope variation, so after solving the problem of time accumulation, only the movement term needs to be corrected."

Perhaps because he was the one involved in the matter, Guo Lin leaned back in his chair and thought for a long time, but still did not respond.

Instead, Xing Muchun, who was just listening casually, guessed something:

"Academician Chang just mentioned cross-range units...does that mean we need to set up multiple antennas at long distances on the same radar?"

In fact, this is just a guess based on the literal meaning, but it has achieved the effect to some extent.

"Yes."

Chang Haonan directly gave further results:

"Specifically, the interval is 154.08 km, or an integer multiple of 154.08 km... Of course, a certain error is allowed, but the smaller the deviation, the easier it is to calibrate the movement item, and the higher the accuracy."

Now that things have come to this, Guo Lin must have understood it.

It's just still a little hard to accept.

"Let several... or even dozens of antennas separated by hundreds of kilometers be controlled by the same terminal?"

He subconsciously glanced at the map of China on the wall at the other end of the conference room.

Even if it only deals with the north direction, it would probably be a mega project of unimaginable scale.

"So I'll call it... Thousand Eyes Patrolling the Sky!"