The campus of the University of Ice Engineering.

After eating breakfast from the cafeteria, the hurried students hurried to class, holding the books used for class in their hands, and walked in three steps and two steps, probably because they were afraid that they would be late.

At the door of the teaching building of the Department of Arts, a brand-new blue GTR suddenly parked, and Li Yun skillfully stopped, the car was still open.

Huangfu Jingshu got out of the car, the snow-white fur swept through every part of the car, and Huangfu Jingshu closed the door.

"I'll go to class, and when you're done, come with me to a place. By the way, this one is for you too! Huangfu Jingshu said, and at the same time handed Li Yun something, a square box.

Li Yun reached out to take it, and when he saw Huangfu Jingshu's white and slender hand, Li Yun suddenly had an urge to eat ice cream.

"After you get out of class, don't forget, I looked at your class schedule, and you don't have classes in the afternoon." Huangfu Jingshu looked at Li Yun with smug in his eyes.

Li Yun was thinking about the box, and he didn't listen much to the words behind it, and when Huangfu Jingshu turned around to leave, Li Yun reacted and said, "What did you just say!" ”

At this time, Huangfu Jingshu had already turned around, and when she heard Li Yun ask stupidly, Huangfu Jingshu smiled sweetly, didn't say anything, waved her hand, and walked towards the teaching building.

Li Yun looked at Huangfu Jingshu's back, a little puzzled, sat in the car, and opened the box.

After the box was opened, it turned out that there was a new mobile phone inside, and it was a smart phone, much better than Li Yun's original slider phone, Li Yun looked up at Huangfu Jingshu again, and he smiled beautifully.

Li Yun turned off his original mobile phone, and then took out the phone card, which was simply manipulated by Li Yun, that is, he could track the location of Huangfu Jingshu.

……

Bisheng Building, large classroom.

Li Yun took the gel pen in his hand and kept turning it in his hand, and Li Yun looked at the courseware content on the projector seriously.

There was an all-round three-dimensional navigation and positioning simulation diagram drawn on the courseware, Li Yun looked at it intently, and instantly Li Yun thought of other things.

At this time, a middle-aged man was a teacher of aerospace science and technology, named Dong Guibao.

Dong Guibao pointed to the courseware on the projector with an infrared lamp on the podium, and said: "Now what the students see is the Big Dipper navigation and positioning system, which consists of two geostationary 800e and 1400e satellites, an orbital backup 110.5e satellite, a central control system, a calibration system, a P520 four-unit terminal server and the user's personal computer. ”

As Dong Guibao spoke, he pointed at each component with the infrared lamp in his hand.

Li Yun looked at the three-dimensional diagram courseware, and suddenly everything was imprinted in his mind, this Big Dipper navigation and positioning system has been imprinted in his brain, and some fragments of the subsystem of the Tianyan system of the Xuanlong Society began to appear in his brain.

"Students, do you know how the Big Dipper works?" Dong Guibao raised his eyes and looked at the students who were doing it and said.

After Dong Guibao finished speaking, there was silence in the classroom, and Li Yun also frowned, after all, he didn't know this.

Seeing that there was no squeak in the students, Dong Guibao said: "It's reasonable that you don't know, so the teacher will tell you." The coverage of the Big Dipper is the heart area between 4 ° and 64 ° north latitude and 60 ° and 150 ° east longitude, with the widest being around 36 ° north latitude, the positioning accuracy is 100 meters horizontally, the working frequency is 2789.1208MHz, and the system can accommodate 6,400,000 users per hour. Two geostationary satellites are responsible for receiving the user's inquiry signal, and after the positioning application is successful, they are sent to the central control system and backup satellites, and then sent out and determined to the user after being processed by the terminal server. ”

After Dong Guibao finished speaking, the students in the classroom all looked at the courseware on the projector with wooden expressions, and they were all dumbfounded.

Li Yun couldn't help but look at the content of the courseware in amazement, why didn't he think of it? No, this Big Dipper needs satellites, but the eye of the sky that Professor Tian talked about, as well as the Zhizi he envisioned, is not through satellites, and has never been tracked and positioned, it seems that the research and development of Zhizi takes time!

The corners of Li Yun's eyes blinked, the corners of his mouth crooked, and he came up with a ghost idea, it seems that the Tianyan system can be run and tried, and then he will find a way to study whether that Zhizi can work.

Seeing that all the students were ambiguous and looked at it in the clouds, Dong Guibao himself said with some embarrassment: "Maybe this system is complicated, but you don't have to be discouraged, the Big Dipper is just a typical case, there will be a variety of navigation and positioning systems in the future, which requires us to innovate while understanding the principle, of course, you need to do it." ”

Li Yun listened to what the middle-aged teacher said, stopped the gel pen in his hand and raised his hand.

When Dong Guibao saw Li Yun raise his hand, it may be a common problem of all teachers, that is, he hopes that some students can take the initiative to ask questions, which may be a great sense of achievement.

"Li Yun, do you have any questions? I heard that you and Professor Tian replied speechlessly, okay! Let me meet you too! Dong Guibao said.

"Hehe, teacher, you made fun of me, I have a question for you." Li Yun said.

"Alright! Teachers are there to answer questions, you ask! Dong Guibao said.

"Teacher, does the navigation and positioning system have to be carried out under the premise of satellites? If our satellites are interfered with, will all communications, navigation and positioning systems be paralyzed? Li Yun asked.

Hearing Li Yun's question, Dong Guibao smiled slightly, and then said, "I can be regarded as a leader today, no wonder Professor Tian can't resist it." ”

"The current technical behavior, the navigation and positioning system relies on satellites, if the satellite is attacked, then the navigation and positioning system will be paralyzed, which is all disadvantages, it is precisely because of this, in addition to the backup satellite, my Big Dipper in Daqin is equipped with a backup satellite, and there are also four-unit terminal servers, which are to prevent hacker inreach, so that the satellite is useless." The middle-aged teacher kept explaining.

After listening to Dong Guibao's explanation, the doubts in Li Yun's heart disappeared, it seems that satellites are the top priority of communication and navigation so far, if Zhizi studies it, then it will replace satellites, so that it will become a system that will not be attacked, because Zhizi is constantly attacking in time.

Li Yun showed a smug smile on his face and said, "Thank you for the teacher's answer, Li Yun understands." ”

At this time, Dong Guibao looked at Li Yun with some puzzlement, not knowing what Li Yun's intention was in asking this, and he couldn't help but have some doubts.

And Li Yun got the answer he wanted, and he was naturally full of satisfaction.

Navigation and positioning class, what Dong Guibao said, Li Yun also recorded it all in his mind, with Erlang's true eyes, Li Yun felt that it seemed to be easier than listening to the class before, and he remembered it very solidly.

When class was about to end, Li Yun took out his mobile phone and looked at it, after having a smartphone, it was more convenient for Li Yun to track the location of Huangfu Jingshu.

Seeing that Huangfu Jingshu was still in the teaching building of the art department, Li Yun was much more relieved.