无网格DEM构建方法研究

项目名称： 无网格DEM构建方法研究

项目编号： No.41501487

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 朱莹

作者单位： 南京晓庄学院

项目金额： 20万元

中文摘要： 无网格DEM是一种散点、形函数和断裂线一体化的数据结构，通过融合数据、方法和地形特征，实现地表模拟在精度和灵活性方面的提高。面向传统地形建模领域高精度模拟、灵活高效更新DEM数据的内在需求，本研究以散点和地形特征线为源数据，在无网格近似方案和DEM构建的理论方法基础上，研究无网格DEM构建的方法体系。分析现有无网格法近似方案的特性，结合实验验证，选择适合于不同地形建模的近似方案；同时，从实现地表的高精度模拟、数据的快速更新和多分辨率灵活转换三个方面，研究无网格DEM的数据结构以及数据组织方式；分析支撑域与地表模拟精度的相关性，研究形函数作用域的确定方法，进而研究形函数的构建方法；考虑保持地表形态特征，研究在形函数中加入地表断裂线的方法；从地形形态和高程数据两方面研究无网格DEM的质量评价体系。 本研究将进一步推动DEM应用的深度和广度，完善DEM构建的理论方法体系。

中文关键词： 数字高程模型；无网格；形函数；支撑域；精度

英文摘要： The Meshfree DEM is a data structure integrated with scattered points, shape functions and fracture lines to improve the accuracy and flexibility on terrain modeling. Facing the requirements of high accuracy of terrain modeling and high efficiency on data updating, this research intents to construct a Meshfree DEM theoretical approach and framework structure based on the Meshfree approximation and DEM construction methods, taking the scattered points and fracture lines as data source. Firstly, the Meshfree approximation is selected for different topography structure by analyzing the characteristics of the approximation and experiments. Secondly, a Meshfree data structure is built from the aspects of high accuracy, high efficiency on data updating and flexible conversion on multi-resolution data. Moreover, from analyzing the correlation between support domain and the accuracy of terrain modeling, the best scope of shape function is determined. Then the shape function is constructed. The fracture lines are merged into shape functions to keep the terrain characteristics. Finally, the quality evaluation system of Meshfree DEM is established based on topography and elevation accuracy.In conclusion, our work will expand the wide and deep area of DEM application and improve the theories and methods of DEM.

英文关键词： Digital Elevation Model;Meshfree;Shape function;Support domain;Accuracy