A Research On Filtering Of Airborne LiDAR Point Clouds Dataassisted With DLG

LiDAR laser technology can quickly, efficiently and accurately obtain thescanned object coordinate information in3D space, after further processing, thedata can be used to produce digital products like DEM, DOM, DSM in highprecision, so in recent years LiDAR has been the rapid promotion and researchapplications.It should filter and extract the point data which is not belong to the surfaceof the ground from the LiDAR laser point clouds data before the use ofproducing digital products, the quality of the filtering and extracting will affectthe precision of the final products directly. Thought analyzing the condition ofthe filtering algorithm should satisfy, the efficiency of the filtering, and theresult of the filtering, it indicates that it is hard to satisfy the filtering precisionautomatically without other assistant data. Based on these factors and combinedthe actual situation and demand of the production units, the paper researchedairborne LiDAR system, proposed a method that use DLG product theproduction units have to assist airborne LiDAR laser point clouds data filtering,the main contents of the thesis as follows:From the filtering methods research and application domain, analyzed thedomestic and foreign situation of the filtering methods research and application,which showed the low efficiency of the production units, and it is meaningful touse assistant data to assist airborne LiDAR laser point clouds data filtering.According to the airborne LiDAR system, the paper investigated theairborne LiDAR system components, operating principle, analysis of thestructure, characteristics and organization of LiDAR laser point clouds data, as well as airborne LiDAR system to complete a production projectimplementation process needs to be done.The paper describes the DLG data selection criteria, the method of the use ofDLG data assisted laser point cloud data filtering principle, according to thedefect of filtering methods, designed a further filtering method using the slopeand slope-based filtering algorithm, and the filter quality evaluation methods indetail. The main idea of the filtering method is to extract the points in thestructure polygon features, assigns the elevation of the points picked out withthe low elevation of the points belong to the ground to keep the otherinformation of the point clouds data. In the final, it used airborne LiDAR laserpoint clouds data and DLG data of one country to test, and designed the filterprogram to accomplish the process, achieved the filtering quality that expectedultimately.In short, as a way of new remote sensing techniques to quickly obtain thethree-dimensional coordinates of terrestrial laser foot point, airborne LiDARsystem has efficient data acquisition efficiency and broad application space.