Chapter 1153 A Gift from Heaven

After listening to Chang Haonan's interlocking plans, the expression on Ding Zhongli's face was very interesting for a moment.

If we sum it up in the way of the later Internet era, it would be...

6.

Not only is he killing someone with a borrowed knife, but the knife he borrowed is actually someone else's own.

The key is to cleverly take advantage of the psychological blind spots of most people. Before the final and most fatal output is made, it is almost impossible for anyone to be prepared in advance.

However, there are still some problems.

Because the premise of all this is that we can really come up with a sufficiently convincing algorithm so that the whole world, or at least the academic community, can accept the methane concentration results inverted from spectral results.

Otherwise, you will end up shooting yourself in the foot.

However, the academic community's ethics on climate and environmental issues...

It can only be said that it is slightly better than the public opinion circle.

But not much.

In fact, even the two most famous comprehensive academic journals in the world, Science and Nature, have clear positions on many issues.

If the research results submitted for a manuscript are inconsistent with the publisher's position, then unless it is an irrefutable god-level paper, it will most likely be rejected.

Therefore, Ding Zhongli still seemed a little worried:

"Academician Chang, I certainly believe in your theoretical ability... But climate research is different from engineering projects. The cycle of observing the evolution of the earth is generally based on 10 years, and it is difficult to come up with a convincing enough result through experimental means..."

"What I'm worried about is that the other party will directly encourage the academic community to oppose the inversion algorithm itself, and the media and the public obviously have no ability to judge whether the algorithm is correct or not. In the end, whoever makes the loudest voice will be right... You know, we generally don't have any advantage in this regard..."

His statement is still too conservative.

China is more than at a disadvantage in terms of public opinion.

He was simply defeated and left with no weapons.

However, Chang Haonan did not expect to rely on domestic media from the beginning:

"If we directly propose a new method for retrieving atmospheric composition, then the purpose is too obvious... Even if the other party cannot directly object, they will be alert in advance, making us lose the surprise of the attack."

"So I plan to start with the theoretical aspects that are not directly related to climate issues. After all, this is my old profession and I still have some influence in this area... After the mathematical and engineering communities have basically recognized the theoretical foundation of the inversion algorithm, I will then launch a more targeted and specific algorithm suitable for the field of atmospheric remote sensing."

Seeing the other party's confident look, Ding Zhongli immediately understood.

This must have been prepared long ago.

He originally wanted to ask what the specific theory was, but after careful consideration, he felt that this was not his area of ​​expertise. It would be a bit embarrassing if the other party explained a lot and he didn't understand anything.

So I just skipped the middle part:

"Then when I return this time, I will sort out the research results accumulated in the past in advance and prepare to assist you, Academician Chang?"

"You can't say that..."

Chang Haonan quickly waved his hand:

"Director Ding has been working on climate change issues for more than a decade. If I intervene once and he becomes an assistant, wouldn't that make me seem like I'm taking over the reins?"

He was not prepared to come forward directly on this matter.

Firstly, the two sides do have different divisions of labor, and the IPCC meetings are basically held in Europe, so it is impossible for Chang Haonan to go abroad casually.

More importantly, in a few years, the AE1500 will need to use low emissions as one of its core selling points.

So he has to play the good guy now so that he can bring up environmental issues later.

Otherwise, if others investigate and find out that it was you who caused trouble a few years ago and ruined the IPCC's assessment report and the climate agreement, then the boomerang will hit you in the head...

In short, both of them were very satisfied with this meeting.

After some mutual flattery, they left...

……

After returning to the laboratory, Chang Haonan immediately turned on his computer and wrote a series of titles on the first page of the document:

"An optimized Levenberg-Marquardt iterative algorithm with global convergence for optimal initial guess and damping coefficient."

This was the first step in his entire plan.

It is also the most important step.

For satellite remote sensing, forward modeling is equivalent to describing the physical process from atmospheric parameters to observed values, that is, using the physical process of radiation transfer to simulate the radiation brightness of the sensor.

Correspondingly, the inversion process is to establish a cost function under the optimization theory and gradually approach the true value in an iterative form.

Specifically for the problem of atmospheric composition detection, in addition to the parameters that can be directly obtained by the sensor, the cost function also includes the error covariance matrix of the observed radiation, the initial value of the unknown target vector, and the covariance matrix that can accurately describe the background field prior value.

The second item does not require complete empirical guesswork because the “known” carbon dioxide concentration can be used as a reference. Therefore, the essence of the inversion problem becomes seeking the minimum value of the cost function.

The most effective method that Chang Haonan could think of in a short period of time, but one that would not arouse particularly high vigilance, was to improve the Levenberg-Marquardt iterative algorithm at the theoretical level.

After all, this algorithm can be used in many iterative optimization problems.

This also includes mechanical processing and fluid dynamics calculations.

For a mathematician who, in the eyes of outsiders, has a background in computer science, it is perfectly normal for him to study this kind of topic.

In fact, if there were more time to prepare, Chang Haonan would be willing to consider some fast algorithms based on neural networks.

Unfortunately, neural networks have relatively high requirements for spectral resolution and require a large amount of statistical data for model training.

Considering that the IPCC’s fourth assessment will begin at the end of the year at the latest, we chose to play it safe.

In fact, under normal circumstances, the normal order of writing a paper is the main text first, then the conclusion, then the abstract, and finally the title.

However, Chang Haonan already had a general idea of ​​the entire content of the article, so after deciding on the title, he went straight to writing the abstract in order.

But after writing only a few words, he stopped typing on the keyboard.

If he was the only author of this article, even with the title of Fields Medal winner, it would seem a bit thin.

Moreover, when Ding Zhongli uses this as a theoretical basis, others can also argue that "this is all a conspiracy of the Chinese" and so on.

But if we can also drag some foreign institutions into this…

Thinking of this, he immediately picked up the telephone receiver at the corner of the table and called Liang Shaoxiu who was in Gaojing...

……

“So… you mean, it is possible to optimize the thermal deformation error of the system point (ERS) during the aircraft assembly process?”

A few days later, Didier Casoré looked at a research report written in two languages ​​in front of him with a look of surprise.

He had already experienced China's theoretical foundation in aircraft pre-assembly.

But even in the production plan at the time, the ERS points, as enhanced reference system points used for calibration, still needed to be manually calibrated by workers.

It's only been more than half a year, and even this step can be done without human intervention. It's really outrageous.

However, his surprise did not last long.

"Of course not now."

Liang Shaoxiu shook his head:

"But in theory, it is possible..."

As expected, Casore took the bait and showed a struggling expression.

After the successful pre-production at the beginning of the year, people in the company often asked whether similar technology could be used on the Falcon 8Z or Rafale.

Even Airbus, the company next door, has people trying to make indirect insinuations.

It’s a very good feeling to be the center of attention.

Unfortunately, he could only give a negative answer every time, and the other party left with a disappointed look in his eyes.

But now, there is an opportunity to follow up the research from scratch...

It is a blessing from heaven.

It's hard not to be moved.

However, Casore still had some self-knowledge after all, and did not give a direct response, but instead put on a distressed expression:

"But I'm an engineer, not a mathematician..."

"Neither am I!"

Liang Shaoxiu interrupted the other party with pretended excitement:

"So I suggest that we jointly sponsor a team of Chinese and French researchers in the name of our two companies to solve theoretical problems... This way we can focus on the production and testing part later, saving a lot of resources and time..."