Beidou satellite navigation system
1916 On April 3, 1916, Chen Fangyun was born in Huangyan County, Zhejiang Province (now Huangyan District, Taizhou City, Zhejiang Province). When he was a child, Chen Fangyun was smart and studious. When he was 5 years old, he went to a private school for education. After the Revolution of 1911, the climax of running new-style schools was set off across the country. Huangyan County also opened new-style middle schools, and mathematics, physics, and English also entered the classroom of Huangyan for the first time. In 1928, Chen Fangyun was admitted to the Middle School in Huangyan County. He was very interested in these new courses and was willing to spend more time studying them, so he developed the good habit of independent thinking. When he was about to graduate from the third year of junior high school, the teacher published an essay titled "Sending Autumn". Chen Fangyun said in the article: "It doesn't matter whether it is sending Autumn or not. For a person, you must work hard on whether it is autumn or spring, summer and winter, and you cannot waste it." From this we can see that Chen Fangyun knew to cherish time when she was a teenager.
From 1931 to 1934, Chen Fangyun completed her high school studies at Shanghai Pudong Middle School. In July 1934, he was admitted to the Department of Mechanics of Tsinghua University. But he is not interested in machinery, but has a special liking for physics. His physics teacher, , Wu Youxun, also noticed this student with excellent grades and skillfulness. Every time he leads his students to do experiments, the bright-eyed student always watches him performing the experiments without missing any details, and is still meticulously making experimental records. After completing the experiment, the student will ask some deeper questions. Professor Wu likes such students from the bottom of his heart, so when Chen Fangyun asked for a request to change his major, he received support from Professor Wu Youxun. Other teachers also saw that Chen Fangyun was a good student in and agreed to his request for transfer, so Chen Fangyun transferred to the physics department.
When I was young, Chen Fangyun
1937, Japan launched a full-scale war of aggression against China, and the eastern school was bombed by the Japanese army. Tsinghua , Beijing, Nankai and other universities were forced to move inward. In April 1938, three universities established National Southwest United University in Kunming, Yunnan. Chen Fangyun came to Kunming with the school and studied radio major in , including , , , Meng Zhaoying, , and other famous professors. During this period, Chen Fangyun met with Shen Shumin, who worked in the Agricultural Research Institute of Tsinghua University. In 1943, the two got married in Chengdu. Since then, they have worked together on the path of science for half a century.
After graduating from Southwest Associated University, Chen Fangyun went to work at the Chengdu Aviation Commission Radio Plant. Shortly after he went there, he created a radio directional instrument and was promoted to the head of the research section. From 1945 to April 1948, Chen Fangyun went to the UK to study . After returning to China in May 1948, he served as a technical officer at the Institute of Physiology and Biochemistry of the Central Academy of Research in Shanghai. Later, the aviation committee sent him to work at Shanghai Airport. Chen Fangyun, who was unwilling to contribute to the KMT fight against Civil War, was punished by the Institute's serious crime, refused to go to the airport and took his wife and children back to his hometown in Huangyan to hide. During the Huaihai Battle, the Aviation Commission transferred Chen Fangyun to work in Nanjing. He refused to transfer the order to again. He ran to Huzhou, Zhejiang to find his father-in-law who was a doctor to remove one of his toenails, causing fake injuries, and returned to Shanghai to be admitted to the hospital. On the eve of Shanghai's liberation, Chen Fangyun persuaded many scientific and technological personnel from the Central Research Institute of to not follow the Kuomintang to go to Taiwan and stay and build a new China.
Chen Fangyun and his wife Shen Shumin and son Chen Xiaodong (1944)
After the founding of New China, Chen Fangyun devoted himself to the construction of New China with full enthusiasm. In 1950, he developed the first set of instruments and equipment in my country's bioelectronics (including electrical stimulators, DC amplifiers and display equipment, etc.). In 1953, Chen Fangyun planned to establish the Electronics Institute of Chinese Academy of Sciences. In 1957, when the Soviet Union sent the world's first satellite to the sky, Chen Fangyun conducted radio Doppler frequency measurements on the satellite to calculate the orbital parameters of the satellite. When others are considering that we also need satellites, Chen Fangyun is already considering how to measure and control the launched satellites. His thinking is always one step ahead of his thinking.
In the following years, Chen Fangyun was engaged in pulse technology research and successfully developed nanosecond pulse sampling oscilloscopes leading internationally and multi-channel pulse analyzers for atomic bomb explosion testing. In 1965, with the development of my country's first artificial satellite " Dongfanghong-1 ", Chen Fangyun was responsible for the tracking, observation and control of this satellite. On April 24, 1970, from the launch of Dongfanghong-1 satellite to the 28 days it worked in the universe, it was clearly recorded by Chen Fangyun using Doppler measurement stations, radar and optical equipment, and continued to measure and calculate it, promptly predicting the time when the satellite flew across the world. This satellite measurement plan, presided over by Chen Fangyun, is very effective. It not only successfully completed China's first satellite measurement mission, but also laid the foundation for the establishment of China's satellite measurement and control network.
Mr. Chen Fangyun, founder of Beidou Navigation System,
In the 1970s and 1980s, Chen Fangyun also participated in part of the development of the "Yuanwang" series of aerospace ocean surveying ships. In August 1977, my country's first aerospace surveying ship, "Yuanwang 1", was built. However, at that time, due to the numerous equipment on board, the electromagnetic interference between various equipment was severely affected, which affected normal work. Chen Fangyun used the frequency distribution method to solve the electromagnetic compatibility problem between many equipment on the measurement ship, so that each equipment can work at the same time without interfering with each other. This achievement won the first prize for national defense science and technology progress. After the successful launch of the Dongfanghong-1 satellite, my country proposed a plan to launch a geosimultaneous communication satellite. After repeated investigation, research and calculation, Chen Fangyun proposed to use " microwave unified measurement and control system " as tracking, orbit measurement, telemetry and remote control during the communication satellite transmission and maintenance synchronization. The biggest advantage of this system is that shares a carrier channel and a set of antennas to perform multiple functions on satellites and other spacecraft . To a large extent, this not only reduces the payload of spacecraft such as satellites, but also reduces ground equipment, saving a lot of funds for the country. Later, after continuous improvement by Chen Fangyun and others in , this "microwave unified measurement and control system" has become more powerful. Around 1982, a "microwave unified measurement and control system" was installed in , Weinan, Shaanxi and Shaxian, Fujian. They cooperated with the "Yuanwang" series of aerospace ocean surveying ships to play an extremely important role in the launch of my country's previous communication satellites. Until today, these two "microwave unified measurement and control systems" are still playing a role.
Yuanwang Ocean Space Survey Ship
is precisely because of its rich experience in spacecraft positioning, tracking, measuring, and controlling, so in 1983, Chen Fangyun proposed to use two synchronous fixed-point satellites to cooperate with the ground station to carry out the regional positioning navigation concept. This system is called " dual-star positioning system ". Subsequently, Chen Fangyun presided over the development of the "Dual Star Positioning System". In 1989, Chen Fangyun and his team used two communication satellites to achieve integrated functions such as rapid positioning, communication and timing of ground targets.
In March 1986, Chen Fangyun , together with Wang Daheng, Yang Jiaqi and Wang Ganchang, proposed and formulated the "863 Plan" for China's high-tech development. In 1994, China officially began the development of the Beidou satellite navigation test system (Beidou-1), and 78-year-old Chen Fangyun personally took charge as the chief designer of the Beidou-1 system. In 1999, Chen Fangyun was awarded the "Two Bombs and One Satellite" Medal of Merit. By 2000, my country launched two geostationary orbit satellites and initially built its own positioning and navigation system. It will be put into use by the end of the year, providing Chinese users with positioning, timing, wide-area differential and SMS services. At this time, Mr. Chen Fangyun, the chief designer of Beidou-1 system, had already passed away in Beijing on April 29, 2000 at the age of 84.
Mr. Chen Fangyun, founder of Beidou Navigation System,
Today, my country's Beidou 3 system has built a Starlink global navigation system composed of 54 satellites, which can provide users around the world with positioning, navigation, timing and other services. It is completely comparable to the GPS navigation system in the United States. As the founder of the "Beidou Navigation" system, Mr. Chen Fangyun can finally smile! Salute to this scientist who spent his whole life "tracking" satellites!
