Chapter 753 Slow Scan Camera
As soon as the leader smiled, Gao Zhendong also spoke happily.

"I have!"

What?! Are you kidding me? I've never heard of us having this thing, and suddenly you have it? This kind of coincidence is really hard to believe.

"Really?" Some comrades couldn't help but ask.

"It's true! I can't go into details, but I can guarantee that this material can store photoelectrons for more than 20 seconds, and even for an hour if necessary."

This material is actually the same one used in the camera tubes of early meteorological satellites. In the era when CCD and CMOS photosensitive components were not yet mature, this special camera tube was used to digitize images. Due to the characteristics of this thing, it cannot take videos, but it can take photos.

Slow-scan camera tube, a special camera device used in early photographic satellites and astronomical observations.

The principle is what Gao Zhendong said, that is, to store photoelectrons on the target surface of the camera tube. This target surface is actually a photosensitive element, and then slowly read out with an AD element. It is a strange element that does the opposite.

But don’t worry about whether it’s weird or not, just tell me if it can be used.

20 seconds? This time is indeed enough to slowly read the low-speed AD components one by one, and there is still some time to spare.

"Comrade Zhendong, are you sure you can do it?" Some comrades were probably scared by the fake satellite launch, and now that a real satellite is being launched, they are afraid that Gao Zhendong will talk nonsense and launch satellites.

The leader of the Defense Work Committee smiled and said, "Zhendong, go ahead and tell me more about it. It doesn't matter here."

But if you want me to say it, Gao Zhendong will not be polite.

"Well, okay, I'll give you a detailed introduction. I work with materials..."

Aren’t you a computer scientist? This question popped into everyone’s mind.

But seeing that the leader of the Defense Work Committee had no doubts on his face, they realized that the computer guy in front of them seemed to be no ordinary person. Was he really a materials expert?!

"…When I was working on some optoelectronic materials, I had some intermediate byproducts. Specifically, one of them was oxygen-doped antimony sulfide. After testing, its leakage current was extremely small, and the photoelectrons generated by the photoelectric effect were retained for a very long time, far exceeding ordinary optoelectronic materials. For example, oxygen-doped antimony sulfide can be retained for more than 20 seconds. This characteristic is not conducive to my goal. Too long a photoelectron retention time will seriously reduce the imaging and detection performance, so I just recorded it, but did not study it in depth."

These words confused everyone because there was too much information.

"Developing certain optoelectronic materials" means that he has successfully developed at least one new type of optoelectronic material.

"Some intermediate by-products." When he was working on optoelectronic materials, there were many technical routes, which are impossible for ordinary people to do.

"One of them" means that he has more than one high-resistivity photoelectric material in his hands.

"No depth", without depth, how do you know that you can even last for more than an hour? I can only say that his "depth" may be higher than the average person's requirements.

Now the other comrades understood why the Defense Work Committee invited him here temporarily. This young man really has something.

As for the Defense Work Committee, they were relieved after hearing what Gao Zhendong said, because Gao Zhendong was working on optoelectronic materials, and this was real. Although the final result was mercury cadmium telluride, he must have tried a lot of things during the preliminary experiments.

After all, the earliest infrared photoelectric material we used was lead sulfide, so it is not surprising that he set his sights on antimony sulfide when he started his research.

The loop is closed, the leader of the Defense Work Committee even closed the loop of the research process of mercury cadmium telluride in his mind. Although he still couldn't figure out where Gao Zhendong got so much time, at least he had completed the process in his mind.

Gao Zhendong had no idea that his leader had thought so much. He was now looking at the comrade who rushed in front of him with some helplessness.

As soon as Gao Zhendong finished speaking, this comrade rushed over and shook Gao Zhendong's hand: "Comrade Zhendong, I really need that material that can last for one hour. It is very useful for astronomical observations."

It’s not surprising that he is an astronomer. It is normal to invite astronomers to study and discuss satellite issues.

Gao Zhendong was startled by him, and probably also realized the problem. This comrade explained: "There are many occasions in astronomical observation that require long exposure, or multiple exposures, such as deep space observation. Now we are suffering from the lack of similar digital exposure methods."

Slow-scan camera tubes were originally used for astronomical observations, so this can be considered a return to their roots.

Gao Zhendong admires these comrades from all walks of life very much. They are very sharp and can grasp the essence of new materials and find the suitable usage direction for themselves in the shortest time.

This requirement is not difficult and it is very easy for the third branch factory to meet it.

"Well, that's no problem. Send me a copy of your requirements later and we'll customize a high-resistance photosensitive target for you."

Upon hearing this, the astronomy comrade happily returned to his seat, with a smile on his face that never disappeared. He didn't expect that a discussion meeting could yield such a reward. Looking at this scene, other comrades also laughed. Anyone would be excited to solve two scientific research problems on the spot, even if the problems might have nothing to do with his job.

Some comrades working in radio, television and communications have even calculated the transmission parameters.

"Hahaha, it doesn't take much. As long as there is a reliable hold time of 10 seconds, I can use a 31kHz signal bandwidth to transmit images of the size of a standard TV frame at a frequency of 10 seconds per frame."

This signal bandwidth is different from the network bandwidth, they are two different concepts. As for how low it is, to put it simply, it is 250 times lower than the TV signal.

Everyone around was getting excited, so it was possible that they could just jump up and reach the bandwidth.

No, I was still worrying about this and that just now, but now it is even possible to upload a picture every ten seconds? Although the picture size of the TV is a bit small, this speed at least means that it is no longer a dream to upload a picture with a usable resolution in one minute?

No, no, many comrades feel that things are very unreal. Who am I? Where am I? What meeting was I just in? Am I still sleepy?

"But it would be difficult for the current C6108 to process images of this size, right? Even if the C6108 is launched and has the image compression algorithm mentioned by Comrade Gao Zhendong, it will not be able to process and compress images of this size very well."

Speaking of this, Gao Zhendong is no longer sleepy. The C6108 is indeed a little bit lacking, but the C6132 is not bad at all. With its specifications, the speed of processing JPG images is acceptable.

"Don't worry about this, it's fine as a plan."

No one knows more about computers than me - very reliable and great.

Read the error-free version at 69shuba! 6=9+shu_ba is the first to publish this novel.

The comrade who raised the question then remembered Gao Zhendong's other identity - a researcher of C6108. Comrade Gao Zhendong's identity is really annoying. He keeps jumping around and always makes people forget what he does.

With Gao Zhendong's words, everyone skipped over this question. In this regard, if Gao Zhendong said one thing, others would not doubt it was two. Although he did not explain it in detail, those who understood would understand.

"It seems that the conditions are basically mature for making photographic satellites the first choice as functional satellites. At least the prospects are bright." A comrade made a summary speech. Even if Gao Zhendong's words cannot be 100% believed, at least in terms of route and prospects, nothing is more reliable than this.

Moreover, this thing is really practical. Apart from anything else, it is attractive enough just as a weather satellite.

"Well, I agree with Comrade Gao Zhendong's suggestion."

"I agree."

"Me too."

"..."

Seeing that everyone's opinions were very consistent, the leader of the Defense Work Committee smiled and said, "Well, this matter will be included in the planning content of the onboard payload and submitted for review as part of the overall planning proposal. The third satellite will test photography, and the second one will test telemetry, space environment, and onboard power supply..."

Just when we got to this point, a comrade suddenly discovered that a problem had been missed.

"Wait, leader, there is another problem. Power supply! What should we do with the power supply? What power supply should be used for the second star test?"

This sentence seems abrupt, but it really reminds everyone, power supply, if this is the case, then the third satellite must work continuously, how to get the power supply? In any case, the second satellite must test the power supply for the third satellite, but what power supply should the second satellite use?
Gao Zhendong had never thought about this. Power source? Aren't there solar panels?

But he soon realized that he had been spoiled by the photovoltaic industry in his previous life.

"Yes, this method does not allow the use of batteries."

This sentence reminded Gao Zhendong that the reason why the design life of our first satellite was 20 days but the actual working days was 28 days was because it did not have any solar cells at all. Our earliest space solar cells were originally developed in 68, and they were not prepared for the first satellite, but for the second satellite.

In 69, they realized that they had chosen the wrong path, so they changed the technical route and started over again. They finally managed to launch the second satellite into space, and the effect was good. It stayed in orbit for 8 years.

So Gao Zhendong subconsciously thought that things were natural and needn't be mentioned, but at this time, they were actually very difficult.

But it seems there is some good news, as he is not the only one who prepares the technology in advance.

"This is not a big problem. Some companies have made solar cells with N-type substrates, and the conversion efficiency is high. The actual measurement can reach more than 7%. I believe that with further improvements, it can reach about 10%."

This is the chief engineer of the Defense Work Committee introducing the situation. In fact, he is the only one who can introduce it because other comrades basically don't know about this. This batch of solar cells will be used in the desert.

It turns out that we have it. Everyone is relieved. As long as there is solar power supply, we can find a way to combine it with rechargeable batteries to ensure continuous power supply for the satellite. The efficiency can even reach 10%, which can greatly reduce the weight of solar cells. Even Citigroup’s efficiency is only around 15% now.

(End of this chapter)