The Application Of Low-Altitude Drone Technology In The Production Of Large Scale DLG In Guizhou Mountain Area

With the development of social science and technology,traditional engineering measurement methods and traditional photogrammetry technologies have not been able to meet the needs of the society.Photogrammetric systems based on low-altitude drones are exposed.The technology is highly mobile and high.With the advantages of efficiency and low cost,it is possible to quickly produce large-scale DLGs(digital line maps)in harsh environments.It is necessary to study key technologies such as data acquisition,image processing,and digital mapping of the system.The basis for the rapid production and updating of basic geographic information data.Relying on the construction of a new boutique tour loop strip terrain map surveying project in Guiyang City,low-altitude UAV technology is used to acquire the survey area image.Then the original imagery is pre-processed using software such as ENVI and LensDistortion,and Inpho software is used to perform aerial triangulation.Then,based on the space vision Mapmatrix three-dimensional mapping system to produce large-scale DLG,the final accuracy evaluation;For the mountain area vegetation coverage area can not reach the accuracy of the accuracy of 1:1000,the use of Inpho software's SCOP++ module DTM point cloud filter with artificial Manually edit DTMs for improvement.The results of the study:(1)With the increase in the number of image control points,the accuracy of the results of “Airspace 3” can be improved.After the number of control points reaches the “threshold value”,the accuracy improvement effect of “Airspace 3” tends to “saturate”;(2)The DLG accuracy produced by using low-altitude unmanned aerial vehicles in Guizhou mountainous areas meets the requirements of 1:2000 scale as a whole.The area covered by non-vegetated vegetation can meet the accuracy of 1:500 scale;(3)The DTM point cloud is implemented with SCOP++ module in Inpho software.The height accuracy of the filter is matched with manual manual edit of the DTM,and the elevation accuracy of the involved area can meet the tolerance requirement of 1:1000 scale.