DLG辅助的机载LiDAR点云数据滤波研究

发布时间：2018-07-28 17:19

【摘要】：机载LiDAR系统可以快速、高效、高精度地获取扫描对象的空间三维坐标信息，数据经处理后可用于生产高精度的DEM、DOM、DSM等数字产品，因此，近年来得到了快速推广和研究应用。利用机载LIDAR点云数据在生产DEM等数字产品前需首先对数据进行预处理，过滤或提取出非地面点激光点云数据，滤波效果的好坏将直接影响最终成果精度。通过对目前现有滤波算法需满足的条件、滤波效率，以及滤波效果等进行分析表明，仅用点云数据滤波而不增加其他辅助滤波数据源，很难实现满足精度要求的点云数据自动化滤波。基于以上分析及结合生产单位实际情况及需求，本文对机载LiDAR系统、使用DLG数据辅助LiDAR点云数据滤波进行了详细的研究，论文的主要内容为：从滤波方法研究以及应用现状方面，分析了国内外LiDAR激光点云数据滤波方法研究现状以及滤波应用情况，分析表明目前生产单位的滤波效率较低，对于使用辅助数据进行滤波处理以提高滤波效率有较大意义。针对机载LiDAR系统，研究了系统组成、工作原理和LiDAR点云数据结构及特点，介绍了机载LiDAR系统基本处理流程。论文分析了DLG数据选择依据、DLG辅助机载点云滤波方法，并对滤波的结果运用基于坡度和斜率的滤波算法进行再次滤波，介绍了滤波质量评价方法，其中滤波方法主要思想是利用DLG中的构建筑物面要素，提取落入面中的激光脚点数据，，根据其高程值选取最低点作为地面点高程值，并将此高程值统一赋予落入面中的激光脚点数据的高程，最大限度保留了点云数据信息，进而达到滤波效果。最后，选取某县的机载LiDAR点云数据和DLG数据进行了试验，并编制了滤波软件，通过对滤波质量的评价，表明对非地面激光脚点数据的滤波达到了期望的效果。总之，作为一种能够快速获取地面激光脚点三维坐标的新型遥感测量技术手段，机载LiDAR系统具有高效的数据获取效率与广阔的应用前景。
[Abstract]:The airborne LiDAR system can obtain 3D coordinate information of scanned objects quickly, efficiently and accurately. After processing, the data can be used to produce digital products such as high precision DSM. Therefore, it has been rapidly popularized and applied in recent years. Using airborne LIDAR point cloud data before producing digital products such as DEM, it is necessary to preprocess the data first, filter or extract the point cloud data of non-ground point laser, and the effect of filtering will directly affect the accuracy of the final results. Through the analysis of the condition, the efficiency and the effect of the existing filtering algorithms, it is shown that only point cloud data filtering is used and other auxiliary filtering data sources are not added. It is difficult to realize the automatic filtering of point cloud data to meet the precision requirement. Based on the above analysis and combined with the actual situation and requirements of the production units, this paper makes a detailed study on the airborne LiDAR system using DLG data to assist the LiDAR point cloud data filtering. The main contents of this paper are as follows: from the aspect of filtering method research and application, the research status and application of LiDAR laser point cloud data filtering method at home and abroad are analyzed. The analysis shows that the filtering efficiency of production units is low at present, which is of great significance to use auxiliary data for filtering and processing in order to improve the filtering efficiency. Aiming at airborne LiDAR system, the system composition, working principle, data structure and characteristics of LiDAR point cloud are studied, and the basic processing flow of airborne LiDAR system is introduced. This paper analyzes the DLG data selection method based on DLG-assisted airborne point cloud filtering, and uses the slope and slope filtering algorithm to re-filter the results, and introduces the filtering quality evaluation method. The main idea of the filtering method is to extract the laser foot-point data falling into the plane by using the building surface elements in DLG, and select the lowest point as the elevation value of the ground point according to the height value. The height of the laser foot-point data which falls into the plane is given to the height of the point cloud data to the maximum extent, and the filtering effect is achieved. Finally, the airborne LiDAR point cloud data and DLG data of a county are selected and the filtering software is developed. The evaluation of the filtering quality shows that the filtering of the non-ground laser foot-point data has achieved the desired effect. In a word, as a new kind of remote sensing measurement technology which can quickly obtain the 3D coordinate of laser foot-point on the ground, airborne LiDAR system has high efficiency of data acquisition and wide application prospect.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN249;TP79

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