Three-dimensional Modeling Of Large-scale Spatial Objects Based On SDOG-ESSG

With the global as the background of the scientific exploration and production activities more and more,the study of 3D modeling of large-scale objects on the earth is becoming more and more important.At present,the modeling of the earth object focuses on the three-dimensional modeling of the small-scale objects in the local area.However,there are many problems in the existing three-dimensional modeling methods for large-scale objects.In view of these problems and shortcomings,this paper based on SDOG-ESSG and the idea of "from point to line,from line to surface,from surface to body",which uses large-scale object spherical boundary data,surface elevation data and thickness data,presents a kind of three-dimensional model construction method for large scale spatial objects on the earth: first of all,boundary gridding is used to obtain the spatial objects boundary grids by using the boundary data of large scale objects,and then the boundary grid with the boundary polygon gridding is used to obtain the spatial objects boundary polygon area grids,finally,the surface elevation data and the depth data are used to radially extend the boundary region grids of the spatial objects to realize the 3D modeling of large-scale spatial objects.The main contents of this thesis are expressed as follows:Firstly,based on the idea of " replace the curve with a straight line",this paper proposes a gridding method of segmented approximation of spherical arcs.Secondly,this paper proposes a spherical polygon gridding method based on SDOG-ESSG grid.Thirdly,in this paper,it proposes a three-dimensional modeling method of radial expansion using spherical polygonal region grids of large-scale spatial objects.