Research On Airborne Point Cloud Filtering Algorithm And Software Implementation

UAV LiDAR system is being used in more and more engineering survey projects,due to its advantages such as convenience and high efficiency.Due to the characteristics of large data volume and high density of the UAV Li DAR point cloud,conventional processing algorithms cannot achieve the optimal processing efficiency;in the actual measurement process,the point cloud data often has data holes,resulting in incomplete point cloud data,etc.problem.This paper has done the following related research work on the characteristics and problems of UAV Li DAR point cloud:(1)In view of the problem of long time and large memory consumption of point cloud filtering,this paper proposes to solve the directed bounding box of 3D point cloud data before carrying out point cloud filtering.Through the experimental comparison of the measured data,this method can effectively reduce the memory occupation during filtering,and can greatly improve the filtering speed when the point cloud coverage area is large.(2)In view of the existence of void areas in the original point cloud data,which affects the integrity and availability of the data,this paper proposes to classify the void areas first.For the point cloud voids caused by the presence of water bodies in the survey area,the edge of the void is extracted Filling is performed at the lowest point elevation;for voids caused by gaps in the flight zone or instrumentation,the image repair algorithm is used to fill the voids.After the experimental analysis of the measured data,the method is used to fill the cavity,and there will be no terrain fracture,and the filling result is more consistent with the actual terrain.(3)This paper implements a morphological filtering algorithm based on edge height difference,and compares the experiment with the measured data.The results show that the algorithm can effectively filter the feature data under complex terrain conditions.This paper also integrates a directional bounding box solution algorithm,a hole area filling algorithm,and a morphological filtering algorithm based on edge height difference,which is integrated in the Cloud Compare software in the form of a plug-in.