摘要
Underground coal mining inevitably results in land surface subsidence.Acquiring information on land surface subsidence is important in the detection of surface change.However,conventional data acquisition techniques cannot always retrieve information on whole subsidence area.This study focuses on the reconstruction of a digital elevation model（DEM） with terrestrial laser scanning（TLS） point cloud data.Firstly,the methodology of the DEM with terrestrial 3-dimensional laser scanning is introduced.Then,a DEM modeling approach that involves the application of curved non-uniform rational B-splines（NURBS） surface is put forward.Finally,the performance of the DEM modeling approach with different surface inverse methods is demonstrated.The results indicate that the DEM based on the point cloud data and curved NURBS surface can achieve satisfactory accuracy.In addition,the performance of the hyperbolic paraboloid appears to be better than that of the elliptic paraboloid.The reconstructed DEM is continuous and can easily be integrated into other programs.Such features are of great importance in monitoring dynamic ground surface subsidence.
煤炭资源的井工开采不可避免地引起地表沉陷,快速高精度获取地面沉降信息尤为重要。然而,传统的数据获取方法难以满足要求,本研究基于地面激光扫描点云数据重建数字高程模型(DEM)。在介绍地面三维激光扫描重建DEM原理的基础上,提出一种融合NURBS曲面的DEM重建方法,并分析不同曲面拟合模型重建DEM的性能特征。结果表明:基于点云数据和NURBS曲面重建的DEM能够较好地满足精度要求,而马鞍面拟合方法的精度高于椭圆抛物面拟合方法的精度。采用NURBS曲面算法重建的DEM表面连续,易于互操作,对监测分析煤矿开采引起的地表动态沉降过程具有重要意义。
基金
Project(51174206)supported by the National Natural Science Foundation of China
Project(2014ZDPY29)supported by the Fundamental Research Funds for the Central Universities
Project(SZBF 2011-6-B35)supported by the Priority Academic Program Development of Higher Education Institutions(PAPD)of Jiangsu Province,China
