The high-precision terrestrial reference frame,as the spatial benchmark for geodesy,is an important national infrastructure.However,due to the influence of nonlinear factors related to geophysical phenomena,the overal...The high-precision terrestrial reference frame,as the spatial benchmark for geodesy,is an important national infrastructure.However,due to the influence of nonlinear factors related to geophysical phenomena,the overall maintenance accuracy of the ITRF framework is still at the centimeter level.Therefore,accurately characterizing the true trajectories of linear motion,nonlinear motion,and geocentric motion of the reference station is the key to achieve the construction and maintenance technology of a millimeter level terrestrial reference framework.Based on long-term global and regional GNSS observation data,more Chinese geodesy scientists devoted much efforts to the maintenance of millimeter-level geodetic reference framework.The main contributions of this work included the followings:①Dynamic maintenance of millimeter-level terrestrial reference frame;②Research progress on the method of maintenance of regional reference frame based on GNSS;③The progress of CGCS2000 frame maintenance in millimeter level accuracy;④Reprocessing and reanalysis of two-decade GNSS observation in continental China;⑤Research on current GNSS velocity field model and deformation in Chinese mainland;⑥The preliminary realization and evaluation of CTRF2020.展开更多
Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Ac...Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Activity, Method, Object and Information. Based on these four elements, a reference framework called AMOI is proposed to be the guideline for the systematic concurrent product design. Using the AMOI reference framework, concurrent product development system can be structured into four function models (including the activity model, method model, object model and information model) which are interconnected with each other.展开更多
基金National Natural Science Foundation of China(Nos.42274044,41974010,42330113,41804018)。
文摘The high-precision terrestrial reference frame,as the spatial benchmark for geodesy,is an important national infrastructure.However,due to the influence of nonlinear factors related to geophysical phenomena,the overall maintenance accuracy of the ITRF framework is still at the centimeter level.Therefore,accurately characterizing the true trajectories of linear motion,nonlinear motion,and geocentric motion of the reference station is the key to achieve the construction and maintenance technology of a millimeter level terrestrial reference framework.Based on long-term global and regional GNSS observation data,more Chinese geodesy scientists devoted much efforts to the maintenance of millimeter-level geodetic reference framework.The main contributions of this work included the followings:①Dynamic maintenance of millimeter-level terrestrial reference frame;②Research progress on the method of maintenance of regional reference frame based on GNSS;③The progress of CGCS2000 frame maintenance in millimeter level accuracy;④Reprocessing and reanalysis of two-decade GNSS observation in continental China;⑤Research on current GNSS velocity field model and deformation in Chinese mainland;⑥The preliminary realization and evaluation of CTRF2020.
文摘Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Activity, Method, Object and Information. Based on these four elements, a reference framework called AMOI is proposed to be the guideline for the systematic concurrent product design. Using the AMOI reference framework, concurrent product development system can be structured into four function models (including the activity model, method model, object model and information model) which are interconnected with each other.