Chapter 97: Can't see it, what should I do?

With Zhan Nuozhu personally accompanied, of course, the journey was unimpeded.
Several people got into the car that Professor Song had driven and came to the proving ground in the work area. Here is an empty concrete ground square, with a few simple sheds built along the side, some precision equipment is placed inside.
The scene here is so familiar. Tan Zhenhua has conducted countless off-site experiments on this site in his previous life. In fact, the current state here has been maintained until the end of the first decade of the 21st century.
Tan Zhenhua still clearly remembers that the delivery ceremony of China's first truly mobile C3I system was held here. It was a project that Tan Zhenhua participated in in the past.
Different from the large factory building of Fang Leisheng Company, which is mainly developed by the American military radar, the dazzling cutting-edge equipment and instruments, and the painting style of wearing a white coat holding a notepad or tablet computer, many of the black technology in the rabbit family are so simple. Developed under the environment, of course, that was before the rabbit’s pockets actually bulged.
When the little money in the pocket slowly filled up, all this quickly changed. I don’t know other places. Before Tan Zhenhua was reborn, at least in 4014, the style of painting was infinitely close to thunder, and it was even worse in many ways. It’s a pity that most of the equipment and meters are still labeled in English. logo.
But let's get back to reality.
Zhan Nuozhu raised his wrist and looked at his watch, and said, "The radar is already on, let's prepare too."
Looking up, on the top of the five-story 801 building, the tallest building in the institute, the huge antenna of a new test radar has begun to rotate.
Tan Zhenhua recognized at a glance that this was a dual-coordinate radar.
The so-called dual-coordinate radar uses mechanical rotating antenna and traveling wave tube technology, and the elevation angle of the search airspace ranges from 20 to 45. In the history of China, this radar technology originated in the 1970s and was put into actual equipment in the early 1980s.
This kind of radar can provide the position and distance of the target, but it cannot provide the high and low angle of the target. In actual combat, an altitude measuring radar must be used.
Regrettably, from Tan Zhenhua's current vision, this is actually a radar "being left behind".
As the speed of current aviation weapons has increased a lot, the use of this old-fashioned detection method has actually been difficult to cope with modern multi-batch, multi-directional, and multi-level air attacks. Therefore, this kind of radar can actually not fully meet the needs of national defense. .
However, China's new radar system is still in the pre-research of pure theory, and even this "backward" radar unit has not yet been equipped on a large scale. Of course, just a few years later, the new three-coordinate radar JY-9 was born and shocked the world.
When Tan Zhenhua was still thinking about it, Professor Song and Professor Guo had already looked at each other and smiled. Professor Song took out a small and delicate flying vehicle from the trunk of the car. Tan Zhenhua looked at it and drooled.
This small aircraft has a pure white body with a beetle-like body in the middle. The whole body is about 20 cm long and 10 cm wide, and generally presents a symmetrical irregular shape.
Different from the soap box on Tan Zhenhua's rudimentary prototype, which was purely responsible for funny, its top surface was smooth and flat. Upon closer inspection, there were circles of lines, which were obviously traces left by the machining of the milling machine.
And in the middle of the bottom of the fuselage, a lens protrudes, that should be the 1503 lens. With this body as the center, four cantilevers radiate outward. The top of the cantilever is a propeller, and under the body are two symmetrical brackets that support the entire body. The whole machine is small and clean, exuding the beauty of science and technology, which is similar to the common drones of Tan Zhenhua in later generations.
Professor Guo also took out a square box from the trunk, also white, with an antenna standing upright. This is the remote control.
Professor Song carefully placed the small quadcopter on a clearing and flipped a switch on it. Tan Zhenhua saw a small red light on the fuselage. Professor Guo stared at the remote control in his hand. When he saw a few green light-emitting diodes lit up one after another, he shouted: "Self-check is complete, everything is normal, ready to test flight."
After Professor Song left the quadcopter for a certain distance, he flipped a switch on the panel.
The four propellers made a slight "humming" sound, and quickly rotated. As the joystick in Professor Guo's hand pushed forward, the output power gradually increased, and the elf slowly separated from the ground and climbed vertically upwards. Going over the roof, higher than the treetops, straight to the clouds.
Everyone looked up at the sky. The white elves gave it a good disguise. In everyone's eyes, only a small white dot could be seen. Professor Guo glanced at the simple display made up of a circle of LEDs on the remote control. The screen says: "The current altitude is 800 meters above the ground, which is close to the theoretical ceiling. It is now in a hovering state. The power has been consumed by 5%. Everything is normal. The experiment continues.
Professor Song nodded. Professor Guo lowered the height of the elf to a height of 50 meters above the ground to ensure that he could see it clearly. Then he pushed the other joystick and saw that the quadcopter was slightly sideways. , Flying lightly, and under the control of Professor Guo, he drew "8", "circle", and "S" in the air. Professor Guo, who was always on the surface, even yelled, obviously playing very well.
It wasn't until Professor Song shouted: "Don't go around playing, try the camera!" Professor Guo just woke up like a dream and pressed another switch on the remote control.
The elf has been flying in the air for nearly ten minutes. Professor Guo looked at a bunch of light-emitting diodes on the remote control and said regretfully: "There is only about 15% of the electricity left, and we must return home." With his voice and Operation, the white elf flew back to the top of everyone's heads and landed slowly.
Professor Song immediately looked at his watch and said: "In this experiment, a total of twelve minutes and thirty-four seconds were left blank, which is nearly three minutes less than the expected result. It is basically qualified, Lao Guo, how about other projects?"
Professor Guo said: "The control is very good and the expected goal is achieved. We Ning have an average altitude of less than ten meters. The highest ceiling was tested just now, which is about 800 meters. If it is higher, the power consumption will increase sharply, which is meaningless. The maximum speed is 6 meters per second, which basically meets the design requirements."
Professor Song turned to ask Zhan Nuozhu again: "Xiao Zhan, go and ask about the radar signal."
Zhan Nuozhu agreed, turned and walked to a room on the edge of the test field, and called a colleague in the radar test team. After a while, everyone saw him turning back, and the expression on his face was wonderful and wonderful.
Professor Song asked: "How is it?"
Zhan Nuozhu shook his head: "The radar test team said that they had seen a low-speed target."
Professor Guo had already packed his big toys, took out the film and handed it to Zhan Nuozhu. This is a secret location and you can't take pictures casually, so the film must be handed in for review first. He came over and asked, "What is it called ever? "
Professor Song is also full of question marks.
Zhan Nuozhu put the film into his pocket while saying: "It used to mean that this signal was only displayed on the radar for less than a second, then it disappeared, and it was automatically filtered out by the filter."
"Then you can't see it! How can it be so close?"
The two professors looked surprised. These two are experts in designing various airplanes, but their understanding of radar is not that deep.
Tan Zhenhua explained with a smile: "Two professors, this is the case. Radars receive the reflected electromagnetic waves and need to go through a filtering process, because not only airplanes reflect electromagnetic waves, but buildings, mountains, large birds, etc. all reflect electromagnetic waves. These returned signals are messy and disorganized. If they are all displayed on the radar screen, the screen will be crowded and there is no way to distinguish. Therefore, the signal must be filtered to filter out those clutters. Only the height, volume and speed can reach a certain level. Only numerical targets will be marked on the radar screen.
And just now, the flying speed of this little toy we flew was only about 6 meters per second, and the reflection area was about the same as a bird. It must have been filtered out by the radar as a bird filter. "
Although the two professors were a little surprised at Tan Zhenhua’s knowledge, it’s not unreasonable to think of his birth background, so he didn’t have much doubt about what he said, not to mention that there was a more important thing that was completely attracted. Their attention--
"Oh, then our little toy is not equivalent to being invisible on the battlefield, haha, that's great!" The two old men happily clapped and laughed.
When someone laughs, someone jumps. No, one from the test field rushed in.
I saw this person enter the door, without saying anything, came straight to Zhan Nuozhu, with red eyes, jumping on his feet and angrily, grabbed Zhan Nuozhu and yelled: "Can't stand, you give me To make it clear, what kind of thing you are flying here today, why can't I see it on the radar I tested over there!"