Urban public infrastructure is an important basis for urban development.It is of great significance to deepen the research on intelligent management and control of urban public infrastructure.Spatio-temporal informati...Urban public infrastructure is an important basis for urban development.It is of great significance to deepen the research on intelligent management and control of urban public infrastructure.Spatio-temporal information contains the law of state evolution of urban public infrastructure,which is the information base of intelligent control of infrastructure.Due to the needs of operation management and emergency response,efficient sharing and visualization of spatio-temporal information are important research contents of comprehensive management and control of urban public infrastructure.On the basis of summarizing the theoretical research and application in recent years,the basic methods and current situation of the acquisition and analysis of spatio-temporal information,the forecast and early warning,and the intelligent control of urban public infrastructure are reviewed in this paper.展开更多
The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significan...The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications.展开更多
With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation services.Limited by volume,weight,power consumption,and r...With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation services.Limited by volume,weight,power consumption,and running time,the in-flight performance of navigation augmentation payload remains to be investigated.In this paper,we analyze the data quality of on-board GNSS observation and evaluate the precision of short-arc dynamic Precise Orbit Determination(POD)performance based on the WangTong-01(WT01)mission.Furthermore,the downlink navigation measurement data of WT01 satellites are analyzed and compared with the GNSS observations.The results show that the average multipath errors of the WT01 on-board GPS L1,L2 and BeiDou Satellite Navigation System(BDS)B1,B2 code observation are 0.54,0.74,0.65,and 0.58 m,respectively.The short-arc dynamic POD three-dimensional(3D)overlapping accuracy is 7.1 cm.The average multipath errors of downlink navigation signal Z1 and Z2 are 0.81 and 0.80 m,respectively,which at the same order of magnitude as GNSS signals.The maximum Carrier-to-Noise Ratio(C/N0)value of WT01 downlink measurement data can reach 60 dB Hz,which is much stronger than GNSS and indicates the navigation signals of LEO satellites can meet the basic requirement of navigation augmentation.展开更多
Several noteworthy breakthroughs have been made with the BeiDou Navigation Satellite System(BDS)and other global navigation satellite systems as well as the associated augmentation systems,such as the commissioning of...Several noteworthy breakthroughs have been made with the BeiDou Navigation Satellite System(BDS)and other global navigation satellite systems as well as the associated augmentation systems,such as the commissioning of the BDS-3 preliminary system and the successful launch of the first BDS-3 GEO satellite which carries the satellite-based augmentation payload.Presently,BDS can provide basic services globally,and its augmentation system is also being tested.This paper gives an overview of BDS and satellite navigation augmentation technologies.This overview is divided into four parts,which include the system segment technologies,satellite segment technologies,propagation segment technologies,and user segment technologies.In each part,these technologies are described from the perspectives of preliminary information,research progress,and summary.Moreover,the significance and progress of the BeiDou Satellite-based Augmentation System(BDSBAS),low earth orbit augmentation,and the national BeiDou ground-based augmentation system are presented,along with the airborne-based augmentation system.Furthermore,the conclusions and discussions covering popular topics for research,frontiers in research and development,achievements,and suggestions are listed for future research.展开更多
基金Jinqiao Project Seed Fund of Beijing Association for Science and Technology(No.ZZ19018)。
文摘Urban public infrastructure is an important basis for urban development.It is of great significance to deepen the research on intelligent management and control of urban public infrastructure.Spatio-temporal information contains the law of state evolution of urban public infrastructure,which is the information base of intelligent control of infrastructure.Due to the needs of operation management and emergency response,efficient sharing and visualization of spatio-temporal information are important research contents of comprehensive management and control of urban public infrastructure.On the basis of summarizing the theoretical research and application in recent years,the basic methods and current situation of the acquisition and analysis of spatio-temporal information,the forecast and early warning,and the intelligent control of urban public infrastructure are reviewed in this paper.
基金National Key R&D Program of China(No.2021YFB3901301)National Natural Science Foundation of China(Nos.42074043,42122026,42174038)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y9E006033D)。
文摘The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications.
基金the National Key Research and Development Program of China[grant numbers 2017YFB0503402,2019YFC1511504].
文摘With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation services.Limited by volume,weight,power consumption,and running time,the in-flight performance of navigation augmentation payload remains to be investigated.In this paper,we analyze the data quality of on-board GNSS observation and evaluate the precision of short-arc dynamic Precise Orbit Determination(POD)performance based on the WangTong-01(WT01)mission.Furthermore,the downlink navigation measurement data of WT01 satellites are analyzed and compared with the GNSS observations.The results show that the average multipath errors of the WT01 on-board GPS L1,L2 and BeiDou Satellite Navigation System(BDS)B1,B2 code observation are 0.54,0.74,0.65,and 0.58 m,respectively.The short-arc dynamic POD three-dimensional(3D)overlapping accuracy is 7.1 cm.The average multipath errors of downlink navigation signal Z1 and Z2 are 0.81 and 0.80 m,respectively,which at the same order of magnitude as GNSS signals.The maximum Carrier-to-Noise Ratio(C/N0)value of WT01 downlink measurement data can reach 60 dB Hz,which is much stronger than GNSS and indicates the navigation signals of LEO satellites can meet the basic requirement of navigation augmentation.
基金the National Natural Science Foundation of China(No.61571309)Talent Project of Revitalization Liaoning(No.XLYC1907022)+1 种基金Natural Science Foundation of Liaoning Province(No.2019-MS-251)High-Level Innovation Talent Project of Shenyang(No.RC190030).
文摘Several noteworthy breakthroughs have been made with the BeiDou Navigation Satellite System(BDS)and other global navigation satellite systems as well as the associated augmentation systems,such as the commissioning of the BDS-3 preliminary system and the successful launch of the first BDS-3 GEO satellite which carries the satellite-based augmentation payload.Presently,BDS can provide basic services globally,and its augmentation system is also being tested.This paper gives an overview of BDS and satellite navigation augmentation technologies.This overview is divided into four parts,which include the system segment technologies,satellite segment technologies,propagation segment technologies,and user segment technologies.In each part,these technologies are described from the perspectives of preliminary information,research progress,and summary.Moreover,the significance and progress of the BeiDou Satellite-based Augmentation System(BDSBAS),low earth orbit augmentation,and the national BeiDou ground-based augmentation system are presented,along with the airborne-based augmentation system.Furthermore,the conclusions and discussions covering popular topics for research,frontiers in research and development,achievements,and suggestions are listed for future research.
