机载LiDAR技术在第三次全国国土调查中的应用及精度分析

Application and accuracy analysis of airborne LiDAR technology in the Third National Land Resource Survey

为研究机载激光雷达(Light Detection and Ranging,LiDAR)技术在第三次全国国土调查中的适用性及测绘成果的精确性,本文以广东省某山区乡镇为研究对象,采用机载LiDAR技术,获取研究区点云数据信息,通过设置点云滤波参数及人工判读方式对点云数据进行去噪处理,构建数字高程模型(Digital Elevation Model,DEM)和数字正射影像图(Digital Orthophoto Map,DOM)模型,生成研究区地籍图。此外,以高精度实时动态(Real-Time Kinematic,RTK)载波相位差分技术和全站仪等仪器测量成果为真值,对地籍图精度进行分析评定。结果表明,采用机载LiDAR技术获得的地籍图平面位置中误差为0.0362 m,高程中误差为0.0477 m,界址点间距中误差为0.0418 m,均小于0.05 m,满足国家地籍测量规范要求。因此,机载LiDAR技术在国土调查中具有较高的适用性,其测绘成果满足规范精度要求,可显著提高作业效率。

In order to study the applicability of airborne LiDAR technology in the Third National Land Resource Survey and the accuracy of mapping results,this paper takes a village in a mountainous area of Guangdong Province as the research object and uses airborne LiDAR technology to obtain point cloud data information in the research area.Point cloud data were denoised,DEM and DOM models were constructed,and cadastral maps of the study area were created by setting point cloud filtering parameters and manual interpretation.In addition,the precision of cadastral map was analyzed and evaluated using the measurement results of high-precision RTK carrier phase difference technology and total station as true values.The results show that the horizontal mean square error and vertical mean square error of the cadastral map obtained by airborne LiDAR technology is 0.0362 m and 0.0477 m respectivelly,and the mean square error of boundary point spacing is 0.0418 m,all of which are less than 0.05 m,meeting the requirements of the national cadastral survey specifications.Therefore,airborne LiDAR technology can be widely used in land resource survey,and its surveying and mapping results meet the accuracy requirements of the specifications,which can significantly improve operational efficiency.