机载LiDAR技术在复杂地形铁路定测阶段的应用研究

The application Research on Airborne Light Detection and Ranging in Railway Location Survey with Complex Terrain

为提高新建铁路定测阶段测量工作效率,在某复杂地形新建铁路项目中,基于其使用机载LiDAR点云数据进行中线测量、横断面测量、地形图测绘等作业,并对数据精度进行分析比较。在LiDAR断面测量时,基于Terrasolid软件得到的成果数据冗余量大,提出一种改进的道格拉斯-普克算法,以达到既反映地形变化又减少断面点数量的效果。在项目横断面测量中,大量实测数据与LiDAR点云测量数据的对比分析表明,在植被稀疏的平地、丘陵地区,97.25%的断面点高差较差小于0.35 m,100%的断面点高差较差小于0.5 m;在植被茂密的高山地区,73.33%的断面点高差较差小于0.35 m,95.15%的断面点高差较差小于1.0 m。因此,在复杂地形铁路定测阶段,LiDAR数据生产宜采用内业生产为主,外业测量检核为辅的作业模式。

In order to improve the efficiency of the measurement in railway survey,this paper adopted a railway project with complex terrain,analyzed and compared the operation process and data accuracy of three methods including center line survey,cross sectional survey and topographic map surveying.For the LiDAR cross sectional survey,redundant data was obtained on the basis of Terrasolid software,the improved Douglas-Peucker algorithm was proposed to reflect the changes of the terrian and reduce the number of sectional points.When applying cross sectional survey of the project,by comparing a large number of the measured data and the LiDAR point cloud data,for flat and hilly areas with sparse vegetation,97.25%of the cross sectional points had an elevation difference of less than 0.35 m,and 100%of the cross sectional points could be controlled within 0.5 m.While in the mountainous and alpine areas with dense vegetation,73.33%of the cross sectional points had an elevation difference of less than 0.35 m,and 95.15%of the cross-sectional points had an elevation difference of less than 1.0 m.It is concluded that in the stage of railway location survey with complex terrain,when operating LiDAR method,designer should mainly focus on internal production,with field survey and verification supplemented.