基于地形断裂线约束的机载激光点云高精度滤波方法  

An accurate breakline-aware filtering method for airborne laser scanning point clouds

作　　者：杨宇妍 臧玉府 肖雄武 管海燕 彭代峰 YANG Yuyan;ZANG Yufu;XIAO Xiongwu;GUAN Haiyan;PENG Daifeng(School of Remote Sensing&Geomatics Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China;State Key Laboratory of Information Engineering in Surveying,Mapping&Remote Sensing,Wuhan University,Wuhan 430079,China)

机构地区：[1]南京信息工程大学遥感与测绘工程学院,江苏南京210044 [2]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430079

出　　处：《测绘学报》2023年第12期2164-2177,共14页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(42171433,41701529);江苏省高等学校自然科学研究项目(17KJB420004)。

摘　　要：现有滤波方法在地形复杂、高程突变等区域往往会错误滤除大量地面点,降低了滤波结果的准确性且严重影响了后续应用。为此,本文提出一种融合断裂线约束模型的采样线高效滤波方法。首先,基于点曲率及邻域范围内距离之和创建约束能量项,改进Snake能量模型,并通过能量函数最小化提取断裂线特征;然后,从测区中获取点云序列等间距构成采样线,构建正三角模型、计算点云平坦度融合断裂线约束过滤每条采样线上的点;最后,根据采样线上的地面点通过改进最小二乘法拟合全局曲面,并结合其实际高程值过滤区域非地面点。为验证本文方法的有效性,本文采用5份不同区域场景的机载激光点云数据进行试验分析。结果表明,本文方法在效率和精度方面优于参照方法,平均滤波精度高达96.58%,尤其在地形断裂区域处滤波效果显著。The existing filtering methods often mistakenly filter a large number of ground points in areas with complex terrain and abrupt elevation,which reduces the accuracy of filtering results and seriously affects the subsequent application.For this reason,this paper proposes an efficient filtering method for sampling lines by fusing the breakline constraint model.Firstly,a constraint energy term is created based on the sum of point curvature and distance in the neighborhood,and the Snake energy model is improved,and features of breaklines are extracted by minimizing the energy function.Then,the point cloud sequence is obtained from the survey area to form a sampling line at equal intervals,and the regular triangle model is constructed,the flatness of point clouds is calculated,and the points on each sampling line are filtered by fusing the breakline constraint.Finally,according to ground points on the sampling line,the improved least square method is used to fit global surface,and the non ground points in the region are filtered according to their actual elevation values.In order to verify the effectiveness of this method,this paper uses five airborne laser point cloud data from different regional scenes for experimental analysis.The results show that the proposed method is better than the reference method in terms of efficiency and accuracy,and the average filtering accuracy is as high as 96.58%,especially in the terrain fault area.

关 键 词：机载点云 采样线滤波 断裂线约束 局部曲面拟合 

分 类 号：P237[天文地球—摄影测量与遥感]