Lao Guo's brows immediately knitted together, doubts appeared in his eyes, and he asked Xu Yun:
"Comrade Han Li, you might as well speak more clearly."
He can understand the word "high cost", and he still understands the logic that scientific research requires money.
Moreover, whether as an overseas student or after returning to China, Lao Guo has been exposed to many high-cost instruments, and he has quite a wealth of knowledge in this area.
Don't mention anything else.
Just mentioning the nuclear radiation dose detection instrument at their base in the 2nd branch factory, the total cost is more than one million - the value of one million in this era is a quite terrifying figure.
But instead of mentioning the cost, Xu Yun mentioned the words "dare you use it", and he couldn't help but feel confused.
After all, the production and research of instruments is different from treating diseases and saving people. In the medical field, it is relatively normal to talk about "dare you dare".
For example, there is a kind of medicine in traditional Chinese medicine called Aconite, which is very harmful to the human body when overdosed. Only doctors from the Vulcan sect "dare" to use Aconite in large quantities.
But instrument production does not need to consider the issue of excess equipment, so where does this so-called dare start?
Looking at Lao Guo with a confused look on his face, Xu Yun grinned a terrifying smile and explained to him:
"Gong Guo, you may not know that the signal processor can also be divided into several modules due to structural problems."
"That is, signal receiving module, signal storage module, signal analysis module, filtering module, signal processing module, quality control module, parameter configuration module, etc."
"Of course, for our current situation, several modules can be ignored or simplified."
Same as the previous radar design.
In terms of signal processor, Xu Yun came up with a Doppler weather radar design that was common in later DIY circles.
This solution was originally a patent designed by Qu Kaifeng, with the patent number .1.
However, everyone in the DIY circle knows that the cost can be saved as much as possible, and the main thing is a low price and high performance-to-price ratio.
Therefore, in terms of the configuration of parts, it is impossible to completely reproduce the original design drawings.
Probably around 2019.
After being simplified by many big names in the circle, including [Ali], [Snot Bibimbap], [sjdendndeej], [Hashimoto Arina’s Dog] and [Starlight Journey].
The DIY circle finally came up with a civilian version of the signal processor design, which is still in use today.
"The signal receiving module is relatively simple."
On the hospital bed, Xu Yun drew a square frame in the air:
"It, the signal analysis module, and the filtering module can be combined into one functionally."
"That is to say, it is enough to identify the clutter fed back and filter out the ground object signals."
Lao Guo thought for a moment and nodded slowly.
This is not difficult to operate.
At present, the base...and even the troops across the country are in the iteration period of military equipment. From the groundbreaking of the base to the present, the military radars of the base garrison have also gone through a round of replacement.
As far as Lao Guo knows.
As of now, there are about three to four radars in the warehouse that are in a semi-abandoned state.
As long as an orthogonal linear polarization frequency domain module is removed from these radars and the filtering of the orthogonal baseband signals is completed, the requirements mentioned by Xu Yun can be easily fulfilled - after all, it is just simple filtering without analysis.
.
This is like using a fishing net to catch fish.
The task of the fishermen in this module is very simple. They only need to filter the small fish and ensure that the fish caught are larger than a certain number of centimeters.
As for the type of fish, specific family and genus information, they do not need to identify it.
Then Xu Yun paused and continued:
"As for the quality control module and parameter configuration module, it is also very easy. Just make a threshold for the quality control factor. About four threshold channels are needed."
"That is, the iq signal of the horizontal low-gain channel, the iq signal of the horizontal high-gain channel, the iq signal of the vertical low-gain channel, and the iq signal of the vertical high-gain channel."
This time, Lao Guo was a little confused.
After all, he is not an expert in algorithms and cannot be proficient in everything.
However, he had roughly come across the terms control factor and threshold. Not long ago, he heard his friend Dong Tiebao talk about the twelve thresholds.
So look at it from this perspective.
Four thresholds shouldn't be a big problem... right?
But Lao Guo's mood did not relax.
After all, the simpler the modules Xu Yun proposed earlier, the more complex the subsequent modules will be.
And no matter which of the above modules it is, it does not involve the category of "dare or not".
Another moment passed.
When Lao Guo had almost digested the content, Xu Yun said again:
"Gong Guo, the first five modules are the two most basic 'levels', and the next two modules are much more difficult."
"The third level among them is... the signal storage module."
When he said these words, Xu Yun's expression was a little serious.
Regardless of the fact that signal storage will be regarded as an extremely basic project in the data industry in 2023, mobile phones will always start with 256G.
But for today's era, data storage is a very troublesome thing.
for example.
Today's data storage mainly relies on punch cards or magnetic drum memory. The largest magnetic drum memory currently in China is located on the 104 machine.
The memory unit is 12 inches long, has 30 tracks, rotates per minute, and has an extremely astonishing storage capacity...
20KB.
That's right.
20KB.
In fact, let alone domestic.
Even in the international front-end field, the world's first hard drive was born only five years ago.
That hard drive consists of 50 24-inch disks, with a total capacity of 5 million characters, which is less than 5MB.
The Doppler weather radar needs to collect as many as 50 million sets of data this time. Considering the timeliness of weather data, it can only be collected in 10 times at most.
This chapter is not over yet, please click on the next page to continue reading! That is, at the end of each round of collection, the weather radar must store 5 million sets of data.
Calculating a set of data based on 3 bytes, 5 million sets are enough for rabbits to drink a pot.
However, what surprised Xu Yun was.
This time, Lao Guo's brows only frowned slightly, and then relaxed quickly:
"Signal storage module, right? No problem, Comrade Han Li, this factory has the ability to solve it."
Xu Yun was stunned for a moment, and a question mark clearly appeared on his disfigured face:
"?"
What's going on?
At first, he thought Lao Guo would be in trouble for a long time. After all, data storage was a real problem for a time traveler like him.
How come it turns out that when we arrive at Lao Guo's place, it seems even simpler than before?
Who is the time traveler? Hey...
But soon.
A guess popped up in Xu Yun's mind.
Could it be...
That thing in the rumors, right?
If that thing really existed, maybe it would really be possible to do this.
Think of this.
Xu Yun couldn't help but feel curiosity and excitement in his heart.
Later generations' views on that thing are somewhat similar to the "Yongle Dadian", that is, about half of the people think that it exists, and half of the people think that it does not exist.
Judging from Lao Guo's current performance, this thing seems to have really appeared...
It's a pity that even if that thing exists, it should be classified as top secret. If Xu Yun asked directly at this time, he would be taken to a small dark room within minutes...
Therefore, he could only suppress his desire to explore for the time being. Anyway, he would have an answer soon.
after awhile.
Lao Guo looked at his notebook again and asked Xu Yun:
"Comrade Han Li, there is only one left of the seven modules you mentioned, which is the signal processing module, right?"
"Signal processing... Is there any difficulty with this module? Or does it require something special?"
Six of the seven modules have been completed, so the remaining one must be related to "dare or not".
At this point.
Just like Xu Yun was curious about "that thing", Lao Guo also had strong curiosity and thirst for knowledge about this module.
"..."
Seeing this, Xu Yun looked up at Lao Guo, thought for a moment, and suddenly said to him:
"Guo Gong, can you give me a pen and paper? This matter needs to be deduced before I can explain it clearly to you."
"Pen and paper?"
Lao Guo was stunned for a moment. After coming back to his senses, he subconsciously looked at Xu Yun and asked:
"Of course you can, but Comrade Han Li, aren't you unable to hold a pen with your hand? What do you need a pen for?"
Lao Guo remembers it very clearly.
When the five cans of cans required a signature and a receipt just now, Xu Yun signed with his fingerprint because he could not hold a pen to sign.
It's only been half an hour since the fingerprints were pressed. It's impossible for Xu Yun's hands to recover in such a short time, right?
While Lao Guo was stunned.
Xu Yun also looked at his right hand and tried to flip it twice in the air. He quickly took two breaths because of the pain:
"Hiss...it hurts...it hurts..."
But soon he raised his head again and explained:
"Guo Gong, I really can't use my hands, but I can use my mouth."
Say it.
Xu Yun also opened his mouth towards Lao Guo.
This can be regarded as one of Xu Yun's "special abilities".
When Xu Yun was in high school, because the textbook content was too simple, he often made some gadgets to relieve his boredom in class.
For example, use staples to make bracelets, draw various car logos on textbooks, and...
Write with a pen in your mouth.
To be honest.
At that time, Xu Yun did not consider hygiene issues, but simply thought it was fun. After taking the pen in his mouth, he wiped it with a tissue and that was it.
A very interesting thing happened later:
At that time, Xu Yun and others were at the stage of switching from ballpoint pens to black sketch pens, that is, they could only use black pens and not ballpoint pens in exams. In the early days, some students never got used to it and often carried less pens.
One time, the little girl at Xu Yun's desk forgot to bring her black pen, so Xu Yun lent her his black pen. Maybe it was because the question was difficult. When Xu Yun looked up one time, he found that the girl had her arms crossed.
I looked at the test paper with rapt attention, while subconsciously chewing on the back end of the black pen...
Well, Xu Yun just picked it up before taking the exam.
Speaking of which, Xu Yun had a crush on that girl when he was studying. She had a neat single ponytail and never wore a skirt. She was quite delicate and pretty. When she recalled her, she was full of youthfulness.
It's a pity that Xu Yun and her were not destined to be together. One went to the University of Science and Technology and the other went to the University of Hong Kong. After graduation, the other went to study abroad and died in a car accident in Tu'ao eight years ago.
well, let's get back to business.
In short, after going back and forth, Xu Yun also developed the skill of writing with a pen in his mouth.
It was just that Xu Yun had previously considered that pressing fingerprints could solve the problem, so Xu Yun did not say anything about this slightly challenging mysophobia.
But now that it was necessary to deduce it, Xu Yun could no longer hide it.
"Write with your mouth?"
Lao Guo raised his eyebrows in surprise, then looked at Xu Yun's mouth, turned around and shouted outside the room:
"Xiao Qiao!"
After a while.
The door of the house was pushed open from the outside, and Qiao Caihong's head poked in:
"Guo Gong, are you looking for me?"
Lao Guo nodded, pointed in a certain direction, and said:
"Xiao Qiao, please go to Director Lin's office to find two ballpoint pens."
Qiao Caihong has no objection:
"okay!"
After Qiao Caihong leaves.
Lao Guo glanced at Xu Yun, shook the pen in his hand at him, and explained:
"Comrade Han Li, the pen is relatively heavy and difficult to write with in your mouth."
"As for the ballpoint pen, I didn't bring it with me today, so you can wait a moment and wait for Xiao Qiao to come back."
Xu Yun glanced sideways at Lao Guo and said nothing.
It's a lie.
Just now he saw two ballpoint pens in Lao Guo's briefcase.
Is it okay that he is obviously a germaphobe?
I didn’t expect that Lao Guo, with your thick eyebrows and big eyes, would actually become scheming...
five minutes later.
Qiao Caihong hummed and came to Lao Guo with two ballpoint pens.
The ballpoint pens these days are still relatively primitive plug-in type, not as convenient as the spring type in later generations, but they are indeed much lighter than fountain pens.
Then Lao Guo opened the cap of the ballpoint pen, took a wooden board to press the paper on top, and placed both in front of Xu Yun.
However, Xu Yun did not rush to start writing immediately, but said to Lao Guo:
"Gong Guo, in order to make it easier for you to follow the train of thought, let's start with the operation scenario of the radar."
"That is, N particles with radial velocity V move toward the radar in the atmosphere. After a beam of electromagnetic waves passes, the radar will theoretically receive N or close to N corresponding echo signals."
"The echoes of the entire sequence have phase changes due to the presence of the target speed, and the task of the signal processing module is to analyze this change to obtain the corresponding information."
"The expression of radar echo is like this..."
Say it.
Xu Yun picked up his pen and wrote down a line of formula:
Lao Guo looked at it for much longer, and his tone was a little confused:
"Comrade Han Li, this is..."
Seeing that, Xu Yun put down his pen and explained:
"A variant in which Ac and Aol are the fixed and random components of amplitude respectively, and θl corresponds to the azimuth angle corresponding to the l-th point, representing the Doppler frequency generated by the l point."
"After you have marked these bytes, you can try to perform reverse inference from the perspective of coherent motion."
"oh?"
Lao Guo couldn't help but raise his voice a little higher. Then he marked the characters as Xu Yun said and started calculating the formula again.
five minutes later.
Lao Guo put down his pen, slowly raised his head, and asked Xu Yun uncertainly:
"Comrade Han Li, according to you...should this formula be multiplied by a high-frequency signal in the form of a complex number?"
Xu Yun shook his head, picked up the pen again and wrote:
A0=[G2λ2(4π)3R4]1/2?γ.
"Look at this."
Xu Yun drew a horizontal line under the item with a pen and explained:
"The echo signal of the radar target can be understood as the delay of the transmitted signal, so as long as a Doppler frequency fd is superimposed on the carrier frequency and the amplitude is multiplied by this scaling factor, the complex steps can be simplified."
"That is to say, the accuracy of the signal processing module is second in the analysis process. The more critical point is that it can carry out oblique processing and obtain the corresponding one-dimensional distance image."
When Xu Yun explained, he emphasized the last two sentences very seriously.
The signal processors of later Doppler weather radars are basically relatively fixed, and the most typical one is TMSC6701.
But whether it is 6701 or 7551, their essence is the same.
That is to say, the clutter that has nothing to do with the meteorological echo is suppressed, and then the specific data of the meteorological information is determined through the θ angle.
To describe it using the previous fishing example...
First use a fishing net to filter out small fish, and then hand it over to professionals for detailed analysis of the fish's family and genus.
The former was solved by Xu Yun in the first module, so the signal processor he designed is mainly used for the latter.
Then here comes the problem.
As we all know.
There are six movable coordinate axes for a particle in space, that is, front, back, left, right, plus up and down.
Among them, left and right and up and down are relatively simple and can be determined through the echo of the outflow interface.
But it will be very difficult if there is a scenario involving forward and backward movement, and more detailed ‘ideas’ must be used to assist.
And for the current rabbit.
The most appropriate idea is obviously...
One-dimensional distance image of scattering points obtained by oblique processing.
That is the normalized echo envelope that many people are familiar with - dash, or the youth version.
And want to complete this idea.
The required tools must meet the following conditions:
Echo data at any angle of θ can be received.
Able to perform orthogonal demodulation slope processing.
It can complete periodic frequency conversion in Ac...that is, the fixed component amplitude process.
And looking at China now.
Within the entire territory of 9.6 million square kilometers, there is only one equipment that meets the requirements.
Think of this.
Bada——
The pen in Lao Guo's hand fell heavily to the ground, and he looked at Xu Yun dumbfounded:
"Xiao Han, are you crazy?! You actually want to dismantle..."
