Spatial interpolation is an important method in the process of DEM construction. However, DEMs constructed by interpolation methods may induce serious distortion of surface morphology in areas lack of terrain data. In...Spatial interpolation is an important method in the process of DEM construction. However, DEMs constructed by interpolation methods may induce serious distortion of surface morphology in areas lack of terrain data. In order to solve this problem, this paper proposes a strategy combining high-accuracy surface modeling(HASM) and classical interpolation methods to construct DEM. Firstly, a triangulated irregular network(TIN) is built based on the original terrain data, and the area of the triangles in the TIN is used to determine whether to add supplementary altimetric points(SA-Points). Then, classical interpolation methods, such as Inverse Distance Weighted(IDW) method, Kriging, and Spline, are applied to assign elevation values to the SA-Points. Finally, the SA-Points are merged with the original terrain data, and HASM is used to construct DEM. In this research, two test areas which are located in Nanjing suburb in Jiangsu Province and Guiyang suburb in Guizhou Province are selected to verify the feasibility of the new strategy. The study results show that:(1) The combination of HASM and classical interpolation methods can significantly improve the elevation accuracy of DEMs compared with DEM constructed by a single method.(2) The process of adding SA-Points proposed in this study can be repeated in many times. For the test areas in this paper, compared with the results with only one execution, the results with more executions are in much more accordance with the actual terrain.(3) Among all the methods discussed in this paper, the one combined HASM and Kriging produce the best result. Compared with the HASM alone, absolute mean error(MAE) and root mean square error(RMSE) of the best result were reduced from 1.29 m and 1.83 m to 0.68 m and 0.45 m(the first test area), and from 0.32 m and 0.38 m to 0.21 m and 0.28 m( The second test area).展开更多
Human activity transforms a land surface into a complex surface where artificial and natural landforms coexist and continuous and emergent landforms merge.In this background,the problems of conventional digital elevat...Human activity transforms a land surface into a complex surface where artificial and natural landforms coexist and continuous and emergent landforms merge.In this background,the problems of conventional digital elevation models(DEMs),such as morphological distortion,complicated updates,and lack of information,are increasingly prominent.This study proposes a new idea of DEM construction based on the concept of geographic ontology.First,landforms with common features are abstracted into a certain type of topographic entity based on their morphologies and semantics.For each type of topographic entity,a DEM was constructed independently based on the available elevation information and other information about the semantics and spatial relationships.Second,individual DEMs were merged into a complete DEM following certain rules.A 1 km2 area located in the suburb of Nanjing,Jiangsu Province,China,was selected as the experimental area.The effectiveness of the model construction method proposed in this study was verified.The results show that the DEM constructed according to the idea of this study has a significantly better performance than the conventional DEMs.The constructed DEM in this study can well represent ground objects,such as slopes,farmland,and ditches.In particular,the constructed DEM ensures the morphological accuracy of the ground objects.展开更多
基金supported by Key Project of Natural Science Research of Anhui Provincial Department of Education (No.KJ2020A0722,No.KJ2020A0721,No.KJ2020A0705)Grant from National Sensor Network Engineering Technology Research Center (No.NSNC202103)+6 种基金National Natural Science Foundation of China (No.41930102)Grant from State Key Laboratory of Resources and Environmental Information System in 2018Key Project of Research and Development in Chuzhou Science and Technology Program (No.2020ZG016)Open Fund of Hunan Provincial Key Laboratory of Geo-Information Engineering in Surveying,Mapping and Remote Sensing,Hunan University of Science and Technology (No.E22136 )Innovation program for Returned Overseas Chinese Scholars of Anhui Province (No.2021LCX014)Anhui Province Universities Outstanding Talented Person Support Project (No.gxyq2019093)Anhui Provincial College Natural Science Research General Project (No.KJ2020B01,No.KJ2020B02)。
文摘Spatial interpolation is an important method in the process of DEM construction. However, DEMs constructed by interpolation methods may induce serious distortion of surface morphology in areas lack of terrain data. In order to solve this problem, this paper proposes a strategy combining high-accuracy surface modeling(HASM) and classical interpolation methods to construct DEM. Firstly, a triangulated irregular network(TIN) is built based on the original terrain data, and the area of the triangles in the TIN is used to determine whether to add supplementary altimetric points(SA-Points). Then, classical interpolation methods, such as Inverse Distance Weighted(IDW) method, Kriging, and Spline, are applied to assign elevation values to the SA-Points. Finally, the SA-Points are merged with the original terrain data, and HASM is used to construct DEM. In this research, two test areas which are located in Nanjing suburb in Jiangsu Province and Guiyang suburb in Guizhou Province are selected to verify the feasibility of the new strategy. The study results show that:(1) The combination of HASM and classical interpolation methods can significantly improve the elevation accuracy of DEMs compared with DEM constructed by a single method.(2) The process of adding SA-Points proposed in this study can be repeated in many times. For the test areas in this paper, compared with the results with only one execution, the results with more executions are in much more accordance with the actual terrain.(3) Among all the methods discussed in this paper, the one combined HASM and Kriging produce the best result. Compared with the HASM alone, absolute mean error(MAE) and root mean square error(RMSE) of the best result were reduced from 1.29 m and 1.83 m to 0.68 m and 0.45 m(the first test area), and from 0.32 m and 0.38 m to 0.21 m and 0.28 m( The second test area).
基金supported by National Natural Science Foundation of China(Grant Nos.41701450,41930102)Program of Provincial Natural Science Foundation of Anhui(No.1808085QD103)+4 种基金Key Project of Natural Science Research of Anhui Provincial Department of Education(KJ2020A0722)Grant from State Key Laboratory of Resources and Environmental Information System in 2018,Key Project of Research and Development in Chuzhou Science and Technology Program(No.2020ZG016)Jiangsu Planned Projects for Postdoctoral Research Funds(No.2018K144C)China Postdoctoral Science Foundation(No.2018M642146)Anhui Province Universities Outstanding Talented Person Support Project(No.gxyq2019093).
文摘Human activity transforms a land surface into a complex surface where artificial and natural landforms coexist and continuous and emergent landforms merge.In this background,the problems of conventional digital elevation models(DEMs),such as morphological distortion,complicated updates,and lack of information,are increasingly prominent.This study proposes a new idea of DEM construction based on the concept of geographic ontology.First,landforms with common features are abstracted into a certain type of topographic entity based on their morphologies and semantics.For each type of topographic entity,a DEM was constructed independently based on the available elevation information and other information about the semantics and spatial relationships.Second,individual DEMs were merged into a complete DEM following certain rules.A 1 km2 area located in the suburb of Nanjing,Jiangsu Province,China,was selected as the experimental area.The effectiveness of the model construction method proposed in this study was verified.The results show that the DEM constructed according to the idea of this study has a significantly better performance than the conventional DEMs.The constructed DEM in this study can well represent ground objects,such as slopes,farmland,and ditches.In particular,the constructed DEM ensures the morphological accuracy of the ground objects.
