Chapter 1002: Photographed an aircraft carrier?

With Chang Haonan’s announcement on the stage, the entire Numerical Algorithms and Computational Science Conference reached its climax.

As for the report session that lasted for a day and a half...

On the contrary, the attention is not that high.

It’s nothing, it’s just too professional.

About half of the actual participants of this conference are from the enterprise side, and one third of them are not professional technicians.

Since Chang Haonan intends to build the conference in the direction of "disciplinary foresight", the content of the reports is mostly theoretical.

For those who can understand it, it can certainly be said that they have gained a lot.

But let alone the media and enterprises, even researchers in the field of numerical computing, if they are not specialized in the topic of the report, are likely to be confused.

The only topic that attracted some attention was that Chang Haonan, who was the first to give a report, was actually giving a report to Professor Jameson, who was the second to give a report.

The former theoretically demonstrates the reasons why the finite volume method may experience result oscillation or even computational divergence when faced with problems with high computational weights, and proposes a feasible solution.

The only problem is that this solution requires first solving the corresponding constitutive equations.

There is no universal format for this equation, and we can only analyze specific problems on a case-by-case basis.

In the process of "finding the equation", apart from the unthinkable method of reinventing the wheel and cracking it by brute force, the most suitable calculation tool is...

TORCH Multiphysics version 2.0.

It's already at the level of killing people and destroying their souls.

Professor Jameson, who came on stage later, almost gritted his teeth and finished the entire speech.

He originally planned to take advantage of COMSOL's victory in the competition to promote the FVM calculation system he had studied throughout his life to all industries and fields.

result……

Promotion, probably it can still be promoted.

However, it may not be promoted by him...

As for Professor Harold Huang, although his report on the application of compact high-precision formats did not cause as much of a stir as the previous two, COMSOL's setback made the business community re-examine the rationality of its past technology routes.

Therefore, he could finally hold his head high.

Although it is still difficult to turn things around in the academic circle if you offend someone.

But at least it has re-entered the vision of many financial sponsors.

For Harold, who had almost reached his despair, this was enough.

The entire conference came to an end amid the joy of the vast majority of people...

……

For Chang Haonan, the previous conference was an interlude, and what happened after the conference was the main line.

a.

Beijing, Tanzhou Tracking and Control Station.

Almost all the management and technical personnel related to Ocean No. 1, including Chang Haonan, Lin Senming and Luan Wenjie, gathered here.

In fact, this satellite, which finally succeeded after going through many hardships, was launched into space as early as the end of March when Chang Haonan was still busy with a numerical computing competition.

According to the plan at the beginning of the project many years ago, Ocean No. 1 will be carried on the same rocket as the Fengyun-1D meteorological satellite, and will finally enter working condition after about half a month of orbit adjustment.

However, due to multiple changes in the research and development direction during the process, especially the addition of optical/radar sea surveillance test missions, the size of the entire satellite increased dramatically.

As a result, the originally planned satellite platforms were unable to bear the entire payload.

Fortunately, the Dongfanghong-5 (-ton class) that was launched on this timeline was launched earlier and had a faster development speed. It caught up with the competition all the way and at least provided a full-state engineering satellite for the Ocean No. project.

By the way, it can also be regarded as a platform test.

Only then was a bunch of expensive precious equipment installed completely.

But once the satellite problem was solved, another trouble followed.

Ocean One needs to operate in a sun-synchronous (SSO) orbit.

In the past, China generally launched SSO orbit satellites using the Long March 4 rocket at the Jinyang Satellite Launch Center.

But the SSO carrying capacity of the Long March 2.5B is only tons.

not enough.

Therefore, they had to temporarily change the plan to launch the Long March 3B from Yuecheng.

The theoretical SSO capacity of over 7 tons is definitely more than enough.

However, theory is theory. The Long March 3B has never carried out a solar orbit launch mission before, so this is also a first.

In short, a single move can affect the entire body.

Almost everything that could be caught up was caught up.

After a series of adjustments, the launch time was limited to a narrow window in the last few days of March.

In this case, Chang Haonan himself would definitely not be able to witness the launch process with his own eyes.

Fortunately, there is still a period from launch to return to work.

Chang Haonan is not a satellite designer, he is only responsible for two software systems: the satellite and the ground.

So, it would be good if he could be there when the satellite first went into operation.

That is now.

"Director Luan, according to the plan, the satellite has officially entered working mode at 3:45 this morning, and will soon send back the first batch of remote sensing photos."

The speaker was Zhang Weiyong, the chief designer of the entire Ocean No. 1 satellite project.

"Will the first batch of photos... definitely pass the screening?"

Luan Wenjie asked, turning his gaze to Chang Haonan.

Because the content captured by Ocean No. 1 is highly sensitive, it is impossible to send the imaging results to nearby receiving stations around the world like general remote sensing satellites, and then transmit them to the Beijing Control Center via ground transmission methods from the receiving stations. Therefore, the communication window is relatively short.

According to the screening algorithm on board the satellite, if the photo does not capture content of interest on the ground, it will not take up the precious ground-to-space link to transmit it back.

"This... still depends a lot on luck."

Chang Haonan explained:

"Aircraft carriers are not like merchant ships. They rarely take fixed routes except for ports and straits. For a single Ocean No. 3 satellite, the shortest revisit period to the same location is 5- days. If you are unlucky, it is normal not to find the target for half a month or even longer."

"However, before sending back each photo, the satellite will first send out an inquiry signal, and the ground can choose to only accept information that has been initially screened by the satellite, or choose not to screen and accept all of it."

The reason for this design is, on the one hand, to provide a safety net -

In case there is a problem with the identification algorithm, at least this satellite can still be used as an ordinary ocean remote sensing satellite instead of becoming scrap metal.

On the other hand, it is also considered that this satellite still has to undertake some scientific research tasks.

Luan Wenjie naturally understood the meaning of these words:

"So... the test we're going to do right now is to accept everything without any screening?"

"Yes."

Chang Haonan gave a positive answer:

"After all, the satellite has just entered operational status, so the focus is still on testing the basic functions of the equipment on it. As for whether the algorithm is effective, we may have to wait a while and try our luck."

"Can't we go take photos of ports, like Yokosuka, or Norfolk?"

A naval leader nearby asked:

"These places are almost always home to aircraft carriers."

"And I remember that Comrade Haonan, you also demonstrated in the previous meeting that the algorithm can identify the special outline of an aircraft carrier under relatively complex background conditions."

“Photographing the port…of course”

Chang Haonan hesitated for a moment, then nodded:

"But it would be better if it could be similar to our expected use case, that is, to capture a target in the high seas. If we shoot at ports, then there would be no point in our marine surveillance system..."

"That's true..."

The other party obviously agreed with this explanation.

As a few people were chatting back and forth, time finally came to the first communication window of the plan.

"Report satellite data!"

Zhang Weiyong walked to the command desk and gave instructions in a deep voice.

Soon, a voice came from the hall of the measurement and control center:

"The onboard equipment and programs have self-checked normally, ready to send back data!"

Next, there were a few seconds of silence.

As Chang Haonan said, this is the first time the satellite reports data.

It will take about 10 seconds.

But this time, the silence seemed a little longer.

"Report!"

The voices of the on-site staff showed a rare hint of hesitation:

"The satellite is reporting that ... there are currently 77920 kilobytes of data streaming."

Having said this, he even swallowed his saliva before continuing:

"16540 kilobytes of data flow... is valid."

"???"

"efficient?"

Chang Haonan, who had just been giving Luan Wenjie a heads-up that he might not be able to photograph any effective targets for half a month, was a little overwhelmed.

Judging from the results, it seems that I was slapped in the face.

But it seemed like he wasn't beaten.

The people around him were also a little stunned because they were not mentally prepared for this situation:

"Effective means that..."

Luan Wenjie walked to the command desk and looked at the display screen in the distance that showed 16540 kilobytes/77920 kilobytes:

"Does that mean... we really photographed an aircraft carrier?"