Feature Extraction Of Surface Changes In Mining Area Based On UAV Photogrammetry

Monitoring of surface changes in mining areas has always been one of the most important links in the field of environmental governance in mining areas.Traditional manual monitoring has low efficiency,and uses discrete single-point data to illustrate the overall topographical changes in the mining area.There is also certain controversy about the robustness of the results;satellite remote sensing monitoring technology has its low-cost and large-scale advantages It is widely used in the environmental monitoring of large-scale mining areas,but its timeliness and flexibility are subject to certain restrictions.In recent years,the low-altitude digital photogrammetry technology of drones has developed rapidly.With the advantages of high precision,high efficiency and low cost,it has become A new type of remote sensing technology complementary to satellite remote sensing technology.However,the research on the detection and extraction of surface change features in mining areas using drone photogrammetry mainly focuses on surface coverage or landscape changes.Most of them are based on two-dimensional image features.The lack of complete detection of three-dimensional deformation features of the surface does not provide a good description of the mining area.The actual changes.Therefore,based on the Terrain 3D reconstruction of UAV photogrammetry,this subject proposes a set of mining area surface change feature extraction methods that combine 3D terrain and 2D images,through the registration of mining area DSM/DEM established in different periods Poor,obtain the three-dimensional change characteristics of the mining area;at the same time,combine the 2D orthophoto to extract the geometric characteristics of the typical surface features to realize the extraction of the geometric features of the mining area and the change characteristics of the surface cover.The results can provide environmental science and disaster warning in the mining area.data support.The main contents of this paper include:1.Discusses the principle and accuracy evaluation method of Terrain 3D reconstruction of the mining area with the UAV image.It mainly includes the construction of three-dimensional digital surface model DSM,digital elevation model DEM and orthophoto DOM.The feature extraction and matching of sequence images,aerial triangulation based on SFM algorithm,and dense matching of sparse point clouds based on SGM algorithm are studied.The system summarizes the whole process of the realization of UAV photogrammetry 3D reconstruction technology,including the field acquisition process of UAV data,the whole process of UAV data 3D reconstruction and the evaluation of 3D reconstruction accuracy.2.According to the characteristics of surface changes in the mining area,this topic proposes a method of combining terrain DEM and image features to achieve the extraction of the geometric features of the mining area and the change characteristics of the surface cover.Aiming at the geometric changes of terrain,the subject studied the feature extraction of surface elevation changes based on point cloud filtering technology on the basis of DEM registration and difference,and proposed an extraction method of three-dimensional change trend features of the surface based on point cloud centroid calculation,which improved the surface Detection of three-dimensional changes.At the same time,for the extraction of features of ground features,threedimensional change detection of roads based on LBD algorithm and three-dimensional change detection of buildings based on DOM vector collection data are studied.3.The subject selected the surface of a working face in the Huaibei mining area as the experimental area,and the three-phase visible light images of the surface of the area were obtained by drones,and the three-dimensional terrain reconstruction and change feature extraction experiments and accuracy verification of the method in this paper were carried out.Combining the site survey situation and the relevant data of the mining area,the extracted change feature information is summarized and analyzed one by one to obtain the complete three-dimensional change information of the surface of the mining area and the change characteristics of typical ground features.tion of the surface of the mining area.The paper has 58 pictures,25 tables,and 83 references.