After implementing CGCS2000,establishing grid models for high-accuracy coordinate transformation which are mainly used to transform border lines and coordinate grids of topographic maps becomes an important issue in m...After implementing CGCS2000,establishing grid models for high-accuracy coordinate transformation which are mainly used to transform border lines and coordinate grids of topographic maps becomes an important issue in mapping applications.Consequently,a grid model for high-accuracy coordinate transformation of CGCS2000 is proposed.Specifically,we firstly analyze a minimum curvature equation of coordinate transformation,which possesses the characteristics of both the global and local smoothness,achieving better consistency with the consecutive smoothness for the coordinate transformation of map’s linear feature.Then an iterative calculation method of grid nodes and an approach for establishing regional grid models based on collocation by two-step minimization are proposed.Meanwhile,a data structure of grid model is constructed.Finally we give the optimized grid interval and transformation accuracy in China corresponding to the proposed grid model.Using 48 433 points of 2000 National Geodetic Control Network of China,we take the proposed model into practice by constructing grid models for coordinate transformation from BJS54 and XAS80 to CGCS2000,and the external positional accuracies for both models are 0.26 m and 0.03 m respectively.展开更多
This article reviews the progress made in geodetic work in China since the 1980s.In order to meet the needs of China’s economic and defense construction,and scientific and social development in the early 21th century...This article reviews the progress made in geodetic work in China since the 1980s.In order to meet the needs of China’s economic and defense construction,and scientific and social development in the early 21th century,some main geodetic actions which should be completed before 2000 are proposed as follows.(1) Monitoring vertical crustal movements and conducting studies on its mechanism.Releveling of the second phase of the national first order leveling network.Computation of the vertical crustal movement.(2) Improvement of national space geodetic network.The main task is to lay down a national B-order GPS network and complete its data processing.(3) Refining of Chinese local gravity field on land and sea.The determination of Chinese local quasi geoid with higher than one meter accuracy.Application of展开更多
基金The National Natural Science Foundation Program(41674019)The National Plan on Key Basic Research and Development of China(2016YFB0501701).
文摘After implementing CGCS2000,establishing grid models for high-accuracy coordinate transformation which are mainly used to transform border lines and coordinate grids of topographic maps becomes an important issue in mapping applications.Consequently,a grid model for high-accuracy coordinate transformation of CGCS2000 is proposed.Specifically,we firstly analyze a minimum curvature equation of coordinate transformation,which possesses the characteristics of both the global and local smoothness,achieving better consistency with the consecutive smoothness for the coordinate transformation of map’s linear feature.Then an iterative calculation method of grid nodes and an approach for establishing regional grid models based on collocation by two-step minimization are proposed.Meanwhile,a data structure of grid model is constructed.Finally we give the optimized grid interval and transformation accuracy in China corresponding to the proposed grid model.Using 48 433 points of 2000 National Geodetic Control Network of China,we take the proposed model into practice by constructing grid models for coordinate transformation from BJS54 and XAS80 to CGCS2000,and the external positional accuracies for both models are 0.26 m and 0.03 m respectively.
文摘This article reviews the progress made in geodetic work in China since the 1980s.In order to meet the needs of China’s economic and defense construction,and scientific and social development in the early 21th century,some main geodetic actions which should be completed before 2000 are proposed as follows.(1) Monitoring vertical crustal movements and conducting studies on its mechanism.Releveling of the second phase of the national first order leveling network.Computation of the vertical crustal movement.(2) Improvement of national space geodetic network.The main task is to lay down a national B-order GPS network and complete its data processing.(3) Refining of Chinese local gravity field on land and sea.The determination of Chinese local quasi geoid with higher than one meter accuracy.Application of
