Research On Modeling Method Of High-precision DEM For Urban Plots By UAV Remote Sensing

High-precision urban DEM is the basic data of constructing digital city at present.As the carrier of human activities,urban plots is an indispensable part of the city,and it is also the focus of research on digital city construction,urban planning and design,urban surface process simulation and urban heat island effect.With the acceleration of urbanization,the topography of urban plots is constantly being transformed by human activities,so that surface morphology shows the characteristics of diversification and discontinuity.Existing modeling methods focus on the expression of continuous terrain.For urban plots with severely fragmented surface,it is difficult to meet the requirements of DEM construction for high-precision urban plots,resulting in morphological distortion of modeling results,which affects subsequent applications.To solve at the above problems,a method of element classification and block modeling considering the morphological characteristics of urban plot elements is proposed.This paper selects JinZhai County of Anhui Province as the research area,ranging from Meishanhu Road to East Tiantangzhai Road,and from South Yingshan Red Avenue to North Hongjun Avenue.Combined with UAV tilt photography-technology,this paper studies the high-precision DEM modeling method of urban plots taking into account the morphological characteristics of plot elements.The main research results and contents are as follows:1、Study on the classification of inner elements of urban plot.The elements with the same morphological characteristics are consistent in DEM morphological expression,but the existing classification methods lack consideration of morphological characteristics of elements,so the existing classification results cannot be directly used to construct complex urban block DEM.In view of the above problems,this paper proposes a high-precision modeling method for urban plot internal elements classification,and summarizes the morphological characteristics of 7 types of elements in the plot,such as roadway,building base and slope.This classification method can better present the basic internal elements of urban plots and their morphological characteristics,and provide a methodological basis for subsequent data collection of urban plot elements and construction of high-precision Urban plot DEM.2、Research on modeling method.In this paper,based on the morphological characteristics of the internal elements of the plot,combined with the idea of"classification,modeling and mosaic",a DEM modeling method of urban plots considering the morphological characteristics of the elements.In this paper,different modeling methods are adopted for road,building base,water area,slope,other artificial elements and natural terrain respectively to construct the morphological fidelity of urban plots DEM.In particular,the intersection boundary convergent road modeling method proposed in this paper takes into account the morphological characteristics of intersection.It can eliminate the distortion of the intersection modeling results caused by the flat-face method.3、The applicability of the proposed method is verified by taking the study area as an example.Results show that the urban plots DEM modeling method based on the proposed in this paper to build the model,able to clearly present the elements and within the outline of the composition of the framework,the modeling results are consistent with the characteristics of object elements morphological characteristics,and the RMSE is less than 0.2 meters in height,realized the high precision modeling expression of urban plots.Figure[37]Table[7]Reference[88]...