Key technologies of China’s new Beidou navigation satellite have been verified.

　　Xinhuanet Beijing, November 23rd (Reporter Shen Anni Yu Fei) The three Beidou navigation satellites newly launched by China this year have recently completed the in-orbit "physical examination" and comprehensive verification of key technologies, and the navigation signal performance index has been greatly improved compared with the previous generation Beidou satellites, reaching the international advanced level.

　　Beidou satellite navigation system is a global satellite navigation system independently built and operated by China, which is compatible and shared with other satellite navigation systems in the world. It can provide high-precision and high-reliability positioning, speed measurement and timing services for all kinds of users around the world, and it also has the ability of short message communication. China launched the 18th and 19th Beidou navigation satellites on July 25th this year, and the 20th Beidou satellite on September 30th.

　　According to the Fifth Academy of China Aerospace Science and Technology Corporation, the research unit of these three satellites, the number of broadcast signals of the new Beidou navigation satellite has more than doubled than before, ranking first among all navigation satellites.

　　"This is a brand-new signal format with independent intellectual property rights. In the same time, navigation satellites can send more signals to meet the needs of users better and faster. " Xie Jun, chief designer of Beidou navigation satellite, said that the research team successfully solved the problems of high power and miniaturization, which made the signal utilization efficiency higher and the signal quality reached the international advanced level.

　　According to reports, the satellite development team innovatively adopted the truss structure design, which increased the effective installation area, reduced the size of the satellite, reduced its own weight and enhanced the function of the platform. The output power of the new platform is larger than that of the previous Beidou navigation satellite, but its mass is less than half of that of the previous one, and its power-to-mass ratio is at the advanced level among similar satellites in the world.

　　According to experts, the electromagnetic and space environment in which Beidou navigation satellite is located is very bad. In order to improve the ability of the new generation Beidou navigation satellite to resist the "wind and rain" in space, the team has improved the adaptability of the satellite’s space environment through a large number of optimized designs, simulations and experiments. Since successfully entering orbit, the three satellites have been working steadily and broadcasting navigation signals all day.

　　Wang Ping, another chief designer of Beidou navigation satellite, said that the development team used inter-satellite link technology to build a global navigation system when it was impossible to deploy stations globally.

　　It is not easy to build a "highway" connecting two small satellites in the vast universe. To this end, experts set up a brand-new autonomous operation subsystem, focusing on the research of inter-satellite link and constellation autonomous navigation technology, forming the design of inter-satellite link network protocol and system scheme with independent intellectual property rights, and doing a lot of simulation tests to avoid many risks.

　　Wang Ping said: "The inter-satellite link function enables communication and ranging between satellites, thus greatly improving the autonomous controllability of the navigation system."

　　According to reports, in order to make the ranging between stars more accurate, the development team has systematically optimized many aspects such as improving signal stability and improving the accuracy of atomic clocks. On August 9 this year, the 18th and 19th Beidou navigation satellites realized inter-satellite link-building for the first time. For more than three months, this space "highway" has been lasting and stable, which has improved the ranging accuracy of users by two times compared with the previous generation Beidou satellite system.

　　Experts say that 98% of the components of the new Beidou navigation satellite have been localized, and all the key components are made in China.

　　Chen Zhonggui, chief designer of Beidou navigation satellite, said: "To build an independent Beidou navigation system, the core must be in hand." To this end, the team repeatedly verified, tested and iterated domestic components, and the time spent was more than three times that of ordinary satellites.

　　According to experts, more than 70 types of nearly 10,000 newly developed domestic components have been applied to the new Beidou navigation satellite, and the localization has been realized for the first time by relying on imported core components such as traveling wave tube amplifier components and high-speed signal processors for a long time.

　　In 1994, China officially started the construction of Beidou navigation system, which was almost 20 years later than the GPS navigation system in the United States.

　　China Beidou navigation satellite system construction implements the "three-step" strategy: the first step is to build the Beidou experimental navigation satellite system in 2000; The second step is to build the regional navigation system in 2012; The third step is to build the Beidou satellite navigation system covering the whole world, which consists of 5 geostationary orbit satellites and 30 non-geostationary orbit satellites around 2020. At present, the first two steps have been achieved, and China has become the third country in the world with its own satellite navigation and positioning system after the United States and Russia.