Quasi-Zenith Satellite
's first sketch
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2010 9 months, the Japanese Quasi-Zenith Satellite launched the first satellite positioning system in an increasingly competitive the field of satellite navigation has taken a big step forward. According to the Japanese mainstream media recently reported that the Quasi-Zenith satellites will be the U.S. GPS (Global Positioning System) to improve the accuracy of a 300-fold, reaching 3 cm, Japan also proposed to use 7 to build their own satellite positioning system satellite. The field of satellite navigation for the Japanese current status and future direction of development and its enlightenment of China's development issues such as satellite navigation, Science and Technology Daily reporter recently interviewed Ocean University of Tokyo, Mr. Fan Chunming GPS expert.
Reporter: What is the status of satellite navigation in Japan?
Fan Chunming: About satellite navigation, the two existing related systems in Japan. One is put into use in 2007 MSAS satellite systems, and the other is now being built in the Quasi-Zenith Satellite System.
MSAS system consists of two geostationary satellites, of which one as a backup. Because it launched with the GPS positioning signals the same as a GPS satellite can be used. MSAS satellite launch GPS navigation message can be compensated to improve the positioning accuracy and reliability, is Asia's regional coverage of wide area differential augmentation systems.
Quasi-Zenith Satellite System by 3 inclined orbit satellites. Through the track design, the view from the Japanese mainland, at any time, one can always have them close to the zenith position, to ensure the building and other buildings of the city and valley to the satellite will not be blocked. In addition to transmitting the same signal with the GPS, it also launched similar with the Japanese MSAS regional wide area differential signal L1-Safe, as well as the unique setting of the signal LEX. September 2010, the first a quasi-zenith satellite ascended to heaven, and after a subsequent 3 months of testing and validation period, while the use of LEX signal to run mapping network base station carrier phase positioning information was tested and evaluated. Japanese media called it the GPS accuracy is increased 300 times, referring to the Mitsubishi Electric Corporation raised the signal using the LEX program test results.
held in November last year, the Japanese GPS / GNSS Forum, was for the Quasi-Zenith Satellite System program raised questions about the intellectual property, as its core positioning technology imported from abroad. Admittedly, in the high-performance car navigation systems and mapping network, and other popular applications, Japan is the world's leading, but in the field of satellite navigation and positioning applications, Japan has not been able to rule the roost in the core technology, which may be followed by Japan's industrial structure and policy related. Japanese academic and research community experts see China, Australia, Canada and the United States and other countries in the satellite navigation University research centers and laboratories are much lamented after, all the universities in Japan do not even have a satellite navigation research center . Although the coverage in the use of LEX in Japan's high-precision positioning of the four pilot programs, but also the realization of completely independent intellectual property rights approach, but the prototype of the method the researchers only by the individual professor in the university research support, lack of special funds . Japanese government investment in basic research lags far behind in the world, this situation occurs not only made the Japanese hard core technology in this area, while the younger generation for the training of professionals are extremely disadvantaged.
Reporter: Japan's development of satellite navigation from here?
Fan Chunming: Although the Quasi-Zenith Satellite System to see the other two satellites are launched the first satellite of the test results may be, but I think the possibility should not be suspended large.
First, although final results are yet to be announced, but the quasi-zenith satellite on October 19 last year, began firing the test signal, the same day of my students received signal success problems not found in nature. Second, just from the principle, Japan MSAS satellites now have the two together has been a quasi-zenith satellite day services may be composed of independent non-dimensional satellite navigation system. If the quasi-zenith satellite all three in place, although the distribution of the satellite positioning and other factors will make the difference more accurate than GPS, but the three-dimensional coverage of Japan's independent regional satellite positioning system has become possible. In such a critical period should not easily give up quasi-zenith system plan. Japan's technology, based on Quasi-Zenith system, based on expansion into the 6-10 inclined geostationary satellite orbit and an independent regional satellite navigation system should be entirely possible.
Reporter: navigation satellite system in Japan What is Enlightenment to China?
Fan Chunming: The above reports will be using the Quasi-Zenith Satellite GPS accuracy is increased by 300 times, but in which there are not only its self-developed intellectual property in Japan is not the problem There's price, such as receiver for the average user is very important since the drive does not solve the problem. On the technical side, the movement for the achievement of 3 cm positioning accuracy of the evaluation of the body are also exaggerated, the right to say that there are various constraints on the positioning accuracy of under it. Really want in the city to achieve full body high precision mobile positioning is similar to multi-path interference, there is need to address the issue. And such basic research is the need for government funding.
of Japanese companies with strong development capabilities, and the Government's investment in infrastructure and effective, making Japan the level of the application is successful. Take for mapping network covering the whole country, without the help of any other means of communication to achieve high-precision positioning is required for mapping the actual requirements of the user a long time, which requires navigation satellites to provide the ground reference station information. Although the original Japanese Quasi-Zenith part of the planned cut off the communication, but still retains a capacity to run with 2kbps channel, with a delivery network covering the whole of the Japanese base mapping information capacity, making only a navigation satellite receiver to anywhere in Japan, the dream of achieving precise mapping possible.
present, China's huge investment in the field of satellite navigation as a whole is correct, I believe that in the near future there will be a great harvest. In the high-tech field, only innovation can ensure sustainable development, and recession in the global environment through the development of the domestic market to increase domestic demand and promote China's manufacturing industry. Innovation project itself has a forward-looking, should not only aim to target the market now. Only in government-funded R & D project review in more attention to the development of future market factors, to avoid the successful completion of R & D projects, while the results have fallen behind the times At the same time, but also pay attention to the role of high-tech SMEs (LEX using Quasi-Zenith High Accuracy coverage programs in mainland Japan there is no intellectual property rights only of individual researchers is that the program, rather than that the world's top Mitsubishi Electric the company's program, which is a good example), a clear improvement in all aspects of the whole industry chain to achieve high-tech achievements into the importance of applications. If in a variety of small and medium enterprises and private high-tech enterprises preferential tax policies, can also be further from the policy to avoid the They create a better environment for the development and space, I believe China will have emerged to provide similar products to the U.S. space shuttle
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