Into Unscientific

  “.Do we dare to use it?”

  In the ward.

   Hearing Xu Yun's words.

  Old Guo's brows were immediately frowned, and doubts appeared in his eyes, and he asked Xu Yun:

   "Comrade Han Li, you might as well make your words clearer."

  He can understand the term high cost, and he still understands the logic of spending money on scientific research.

  Besides, whether he was an overseas student or after returning to China, Lao Guo has been exposed to many high-cost instruments, and he has a wealth of knowledge in this area.

  Don't mention anything else.

  Just mentioning the nuclear radiation dose detection instrument based in the No. 2 branch factory, the total cost is more than one million—the value of one million in this era is quite a terrifying figure.

  But Xu Yun didn't mention the cost but mentioned the four words "dare to use it", and he couldn't help being a little confused.

  After all, the production and research of instruments is different from curing diseases and saving lives. In the medical field, it is relatively normal to say "dare or not".

  For example, there is a medicine called aconite in traditional Chinese medicine, which is very harmful to the human body if it is overdose. Only doctors of the Vulcan School "dare" to use aconite in large quantities.

  But the production of instruments does not need to consider the problem of excessive equipment. Where does this so-called dare to talk about?

  Looking at the puzzled old Guo, Xu Yun grinned a terrifying smile and explained to him:

   "Mr. Guo, you may not understand 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, there are several modules that can be ignored or simplified."

   Same as the previous radar design.

   In terms of signal processors, Xu Yun came up with a Doppler weather radar design scheme that is common in DIY circles in later generations.

  The original body of this solution is a patent designed by Qu Kaifeng, the patent number is CN201811287767.1.

  However, everyone in the DIY circle knows that if the cost can be saved, the cost can be saved, and the main focus is a low-cost and high-efficiency cost performance.

  So in the configuration of parts, it is impossible to completely reproduce the original design drawings.

   Probably around 2019.

   After simplification 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 Minke version of the signal processor design, and it has been used to this day.

  "The signal receiving module is relatively simple."

   On the hospital bed, Xu Yun drew a square frame in the air:

   "It can be combined with the signal analysis module and filter module in a three-in-one function."

   "That is, to identify the feedback clutter and filter out the ground object signal."

  Old Guo thought for a moment, then nodded slowly.

   This operation is not difficult.

  Currently, the base and even the troops across the country are in the iterative period of military equipment. From the groundbreaking of the base to the present, the military radar of the base garrison has also undergone 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 linearly polarized frequency domain module is removed from these radars to complete the filtering of the orthogonal baseband signal, the requirements mentioned by Xu Yun can be easily fulfilled—after all, it is only pure filtering without analysis.

   It's like catching fish with a fishing net.

  The task of the net fisherman in this module is very simple, just filter the small fish and ensure that the length of the caught fish is more than a certain number of centimeters.

  As for information such as fish species, specific families and genus, they do not need to identify them.

   Then Xu Yun paused and continued:

   "As for the quality control module and the parameter configuration module, it is also very easy. Just make a threshold for the quality control factor. It needs about four threshold channels."

   "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 when he heard it.

   After all, he is not an expert in algorithms, and he cannot be proficient in everything.

  However, he has been familiar with the two terms control factor and threshold. Not long ago, he heard his friend Dong Tiebao talk about twelve thresholds.

   So look at it from that perspective.

  Four thresholds should not be a big problem, right?

   But Lao Guo's mood did not relax because of this.

  After all, the simpler the modules proposed by Xu Yun earlier, the more complex the subsequent modules will be.

  And no matter which of the above modules, 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:

   "Guo Gong, the first five modules are the two most basic 'gears', and the next two modules will be much more difficult."

   "The third gear is the signal storage module."

  When Xu Yun said this, his expression was a little serious.

   Regardless of the fact that signal storage can be regarded as an extremely basic project in the data industry in 2023, mobile phones start at 256G at every turn.

  But for the current era, data storage is a very troublesome thing.

for example.

   Today's data storage mainly relies on punched cards or magnetic drum storage. The largest magnetic drum storage currently available in China is located on the 104 machine.

  The memory unit is 12 inches long, with 30 magnetic tracks, 10,000 rotations per minute, and the storage capacity is astonishingly high.

  20KB.

   That's right.

  20KB.

  Actually let alone domestic.

  Even in the international front-end field, the world's first hard drive was born 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 divided into 10 collections at most.

   That is, after each round of collection, the weather radar must store 5 million sets of data.

  A set of data is calculated as 3 bytes, and 5 million sets are really enough for rabbits to drink a pot.

  However, Xu Yun was surprised.

   This time, Lao Guo frowned slightly, and soon let go:

   "Signal storage module, right? No problem, Comrade Han Li, this factory is capable of solving it."

  Xu Yun was taken aback for a moment, and a question mark clearly appeared on his disfigured face:

   "?"

  What's the situation?

  At first, he thought that Lao Guo would be in trouble for a long time. After all, the matter of data storage is a serious problem for a traveler like him.

   In the end, it turned out that Lao Guo’s place seemed simpler than before?

  Who is the time traveler?

   But soon.

  A guess appeared in Xu Yun's mind.

   Shouldn’t it be

   The thing in the rumors, right?

  If that thing really existed, it might actually be possible to do this.

  Think here.

  Xu Yun couldn't help feeling curious and excited.

  The view of later generations on that thing is a bit similar to "Yongle Dadian", that is, about half of the people think it exists, and half of the people think 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 asks directly at this time, he will be taken to the small black room within minutes.

   Therefore, he can only temporarily suppress the desire to explore in his heart, anyway, he will have an answer in a short time.

after awhile.

  Old Guo looked at his notebook again, and asked Xu Yun:

   "Comrade Han Li, now there is one remaining of the seven modules you mentioned, which is the signal processing module, right?"

   "Signal processing. Is there any difficulty in this module? Or do you need to use any special things?"

  Seven modules have solved six, so the remaining one must be related to "dare or not".

   Here we go.

  Just as Xu Yun was curious about "that thing", Lao Guo also had a 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 the pen and paper? I can only explain this to you clearly through derivation."

   "Pen and paper?"

  Old Guo was taken aback for a moment, and when he came back to his senses, he subconsciously looked at Xu Yun and asked:

   "Of course, but Comrade Han Li, isn't your hand unable to hold a pen? What do you need a pen for?"

  Old Guo remembers it very clearly.

  When the five cans of food needed to sign the receipt, Xu Yun pressed his handprint because he couldn't hold a pen to sign.

   It has only been half an hour since the fingerprints were pressed. It is impossible for Xu Yun's hands to recover in such a short time, right?

   While Lao Guo was in a daze.

  Xu Yun also glanced at his right hand, and tried to flip twice in the air, and he quickly gasped twice because of the pain:

   "Hissling, pain, pain."

  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 opened his mouth to Lao Guo.

  This can be regarded as a certain "special ability" of Xu Yun.

   When Xu Yun was in high school, because the content of the textbook was too simple, he often made some gadgets in class to relieve boredom.

  For example, using staples to make bracelets, drawing various car logos on textbooks, and

  Write with a pen in your mouth.

To be honest.

  Back then, Xu Yun really didn’t think about hygiene and other issues, but just thought it was fun, and wiped it with a paper towel after finishing the pen.

   Later, a very interesting thing happened:

  At that time, Xu Yun and the others were in the stage of changing from ballpoint pens to black sketch pens, that is, they could only use black pens instead of ballpoint pens for the exam.

Once, the little girl at the table in front of Xu Yun forgot to bring a black pen, so Xu Yun lent her his black pen. Perhaps it was because the questions were difficult. Staring intently at the test paper, while subconsciously nibbling at the back of the black pen

  Well, Xu Yun passed there just before the exam.

  Speaking of which, Xu Yun had a crush on that girl when he was studying. She has a clean single ponytail and never wears a skirt.

  It’s a pity that Xu Yun and her have no destiny. One went to HKUST and the other went to HKU. After graduation, the other went abroad to study and died in a car accident in Tu’ao eight years ago.

well, let's get back to business.

  In short, Xu Yun also practiced the technique of writing with a pen in his hand.

   It's just that Xu Yun didn't say anything about this slight challenge to cleanliness because he thought that pressing his fingerprints would solve the problem.

   But now that it is necessary to deduce it, Xu Yun can no longer hide it.

   "Writing with your mouth?"

  Old Guo raised his eyebrows in surprise, then glanced at Xu Yun's mouth, turned his head and shouted to the outside:

   "Little Joe!"

   After a while.

  The door of the house was pushed open from the outside, and Qiao Caihong poked his head in:

   "Mr. Guo, are you looking for me?"

  Old Guo nodded, stretched out his hand and pointed in a certain direction, and said:

   "Little Qiao, thank you for your hard work. Go to Director Lin's office to find two ballpoint pens."

  Joe Rainbow has no objection:

"okay!"

   After Qiao Caihong leaves.

  Old Guo glanced at Xu Yun, shook the pen in his hand, and explained:

   "Comrade Han Li, the pen is relatively heavy, and it's not easy to write when you hold it in your mouth."

   "I didn't bring the ballpoint pen with me today, so you wait a moment and wait until Xiao Qiao comes back."

  Xu Yun gave Lao Guo a slanted look, but did not speak.

  Cheat ghosts.

  Just now he saw two ballpoint pens in Lao Guo's briefcase.

   Is it obviously a cleanliness obsession?

   I didn't expect you, Lao Guo, with thick eyebrows and big eyes, to play tricks.

five minutes later.

  Qiao Rainbow hummed and came to Lao Guo with two ballpoint pens.

  Ballpoint pens these days are still relatively primitive, not as convenient as the spring-press type of later generations, but they are indeed much lighter than fountain pens.

  Later, Lao Guo lifted the cap of the ballpoint pen, took another piece of wood, pressed the paper on it, and put the two together in front of Xu Yun.

  However, Xu Yun did not rush to start writing immediately, but said to Lao Guo:

   "Mr. Guo, in order to make it easier for you to follow your train of thought, let's start with the operation of the radar."

   "That is, N particles with a radial velocity of V move towards 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 entire sequence of echoes has a phase change due to the existence 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 the radar echo is like this."

   Say it.

  Xu Yun picked up the pen and wrote down a line of formula:

  s(t, tm)=A0rect(t^2Ri/cTp)exp(j2π((fc+fd)t+12μ(t^2Ri/c)2))A0.

  Old Guo nodded quickly.

  This formula is very concise, but it is not difficult to understand.

   Then Xu Yun quickly wrote down another set of variants:

  C(t, tm)=∑l=1N(Ac+Aol)Gθl2S(t^2Rθl/c,tm)exp(j2πflt).

   This time.

  Old Guo watched for a lot longer, and his tone was a little dazed:

   "Comrade Han Li, this is"

  Xu Yunjian put down his pen and explained:

   "A variant, in which Ac and Aol are the amplitude fixed components and random components respectively, θl corresponds to the azimuth angle corresponding to the lth point, and represents the Doppler frequency generated by the l point."

   "After you have marked these bytes, you can try to reverse them from the perspective of coherent motion."

"oh?"

  Old Guo's voice couldn't help raising his voice a bit, and then marked the characters according to Xu Yun's words, and restarted the calculation of this formula.

five minutes later.

  Old Guo put down his pen, raised his head slowly, and asked Xu Yun uncertainly:

   "Comrade Han Li, according to your statement. Shouldn't this formula be multiplied by a complex high-frequency signal?"

  Xu Yun shook his head, picked up the pen again and wrote something:

  A0=[G2λ2(4π)3R4]1/2γ.

   "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 number steps can be simplified."

   "That is to say, the accuracy of the signal processing module in the analysis process is second. The more critical point is that it can carry oblique processing and obtain the corresponding one-dimensional distance image."

   When Xu Yun explained, he bit the last two sentences very seriously.

  The signal processors of later Doppler weather radars are basically fixed, and the most typical one is TMSC6701.

   But whether it is 6701 or 7551, their essence is the same.

   That is to suppress the clutter that has nothing to do with the meteorological echo, and then determine the specific data of the meteorological information through the θ angle.

   Use the previous fishing example to describe it.

  First use a fishing net to filter out small fish, and then hand it over to professionals for a detailed analysis of the family and genus of the fish.

   Among them, the former was solved by Xu Yun in the module of the first gear, so the signal processor he designed is mainly used for the latter.

   So here comes the problem.

   Well known.

   There are six movable coordinate axes for a particle in space, that is, front, back, left, right, plus down.

   Among them, the left, right and up and down are relatively simple, which can be determined by the echo of the outflow interface.

  But if the scene of moving back and forth is mixed, it will be very difficult, and it must be assisted by more detailed 'ideas'.

   But for the current rabbit.

  The most appropriate way of thinking is obviously

  The one-dimensional distance image of scattered points obtained by oblique processing.

   That is, the normalized echo envelope that many people are familiar with - the dash, or the youth version.

   And want to complete this idea.

  The required tools must meet the following conditions:

   Can receive echo data at angle θ arbitrarily.

  Able to perform quadrature demodulation skew processing.

   It can complete periodic frequency conversion in the process of Ac, that is, the fixed component amplitude.

   And look at China right now.

  In the entire territory of 9.6 million square kilometers, there is only one qualified equipment.

  Think here.

  Bada—

  The pen in Lao Guo's hand fell heavily to the ground, and he stared at Xu Yun dumbfounded:

   "Xiao Han, are you crazy?! You actually want to tear it down"

   "Electrostatic accelerator?!"