Bài viết Kết hợp lọc hình thái và lọc phân bố mật độ đám mây điểm UAV-LiDAR để xây dựng mô hình số địa hình nghiên cứu sử dụng bộ lọc hình thái đơn giản (SMRF) với các tham số phù hợp để phân tách các điểm phi địa hình (điểm địa vật: cây cối, điểm nhiễu, ) và các điểm của bề mặt địa hình. | Journal of Mining and Earth Sciences Vol. 63 Issue 5 2022 1 - 10 1 Combination of morphological and distributional filtering for UAV - LiDAR point cloud density to establish the Digital Terrain Model Anh Trung Tran 1 Hanh Hong Tran 1 Tuan Manh Quach 2 1 Hanoi University of Mining and Geology Ha Noi Vietnam 2 Northern QT Trading and Construction Joint Stock Company Ha Noi Vietnam ARTICLE INFO ABSTRACT Article history Filtering the LiDAR point cloud based the Unmaned Aerial Vehilce UAV - Received 14th Mar. 2022 LiDAR in the dense land cover areas to build a Digital Terrain Model DTM Revised 11th Aug. 2022 is a basic requirement of large-scale topographic mapping. The aim of this Accepted 31st Oct. 2022 paper is to study the use of the Simple Morphological Filter SMRF with Keywords suitable parameters to separate the non-terrain points trees noise points DTM etc. and the topographical points. The methods of this article are Filtering algorithmic programming and combining the two filtering algorithms including SMRF and distributed filtering. The various data input was Land cover studied in the Ba Be case study. These parameters include the grid width Point Cloud called Gcell m the radius of filters called nwd and the threshold of the feature UAV-LiDAR. elevation called Eth m . The point cloud of the terrain obtained after applying the SMRF continues to be filtered using distributional filter with the algorithm keeping only minimum elevation in the filtering window in order to remove the locations of high density of points. Then it will contribute to lighten the point capacity to build DTM to accurately interpolate the contour lines and to ensure the aesthetics of large-scale topographic maps. The results of the study are the fomulas to estimate reasonable input parameters Gcell 3 m nwd 3 Eth m of the two filters for the establishment of a topographic map of 1 2000 scale 1 m level in the Ba Be national forest Bac Kan province Vietnam. Copyright 2022 Hanoi .
