Automatic Extraction Of Power Line And Tower Based On LiDAR Data

Airborne LiDAR technology is a new kind of remote sensing mapping technology,which has the ability to quickly acquire high-precision geospatial information.It has been gradually applied in urban three-dimensional modeling,power inspection,forest resources management and other fields.In power patrol inspection,point cloud data of transmission line corridor based on LiDAR technology are collected to extract power line and power tower,which can quickly and accurately measure the distance between them and the surrounding objects to accomplish the safety monitoring of the transmission lines.However,due to the interference of complex environment in transmission line corridors,algorithms for extracting power line and tower have some shortcomings in adaptability and extraction accuracy.Thus,the requirement of high precision automatic extraction of power line and tower in the application of airborne LiDAR technology in power line patrol is studied.Specific work of this paper includes:In order to eliminate the influence of topographic factors on the extraction of power lines and towers.Firstly,point cloud are filtered by improved mathematical morphology filtering algorithm to get ground point cloud.In the light of the large void area after filtering,the region filling method is used to compensate the interpolation defect of the inverse distance weighted interpolation algorithm for the large void area.The residual ground point cloud after filtering is interpolated to generate DEM(digital elevation model)for extracting candidate points of power line.Experiments on the measured data show that the digital elevation model can be obtained by using the point cloud filtering algorithm and DEM generation algorithm,and the accuracy requirement can be satisfied at the same time.First,before extracting power line points,normalize the non-ground points based on generated DEM(Digital Elevation Model),then the candidate point cloud is obtained based on the elevation characteristics of the power line point cloud and its continuous distribution in Z direction.Secondly,the Hough transform is improved by the peak enhancement local operator,and the precision extraction of the power line point cloud is achieved.Finally,a single power line can be obtained by the nearest neighbor growth algorithm based on the spatial continuity of the power line point cloud.Experiments on the measured data show that the extraction rate is improved by using this algorithm.At the same time the algorithm can accurately extract power line points adapted to the influence of undulating terrain and complex objects,and can identify single line of power lines accurately.According to the characteristics of high density and local maximum height of power tower point cloud,the power tower is positioned,and it accomplishes the extraction of power tower that organized in the form of Kd-tree,to use the nearest neighbor growth algorithms.Experiments on the measured data show that the method can extract the point cloud of power tower successfully.