Geometry-based mapping of vector data and DEM based on hierarchical Longitude/Latitude Grids

Mapping of vector and DEM is one of main methods for ascertaining spatial object locations in 3D dimension space. What´s more, mapping technology has been widely used in the analysis and management of virtual landscape. Various methods of mapping vector data and DEM on the plane have been approached. However, when those methods are used for mapping global-scale vector data set and DEM model, they do have some significant drawbacks, such as improper matching in geometry-based mapping, heavy texture distortion in texture-based mapping etc. To overcome these deficiencies, a new geometry-based method based on hierarchical Longitude/Latitude Grid, which is the simplest and most useful one of global discrete grids, is developed in this paper. Our approaches start with dividing longitude/latitude grids on the spherical surface hierarchically. Then, constructing global DEM model base on this structure is presented in brief. Next, the detailed geometry-based mapping algorithm is introduced. In the end, the experiment is made to test the algorithms and methods by using GTOPO30 and Chinese county boundary data. The result indicates: the methods and algorithms discussed in this paper are feasibility and effective.