Study On The Technology Of 3d-DLG With The Aerial Image And Lidar Point Cloud

The active-passive multi-sensor combined wide-angle imaging system(APCI)which combined of GNSS+INS+LiDAR+RGB Camera was developed due to the need of surveying and mapping emergency business.Analyzing the data obtained from the current system,I found that the data fusion by the four sensors is insufficient,thus inspired,the idea of developing 3d-DLG(three dimensional Digital Line Graphic)technology system was developed.The main research contents,technical route and innovation points can be summarized as follows.(a)Due to the lack of accuracy of GNSS+INS,the DSM formed by the LiDAR point cloud has plane distortion and the image of the plane array camera has azimuth element error.So this paper put forward the method of building adjacent aerial orthophoto projection and image matching which solved the relative orientation elements of the residual error and the method of feature matching of the edge of correction orthophoto and the LiDAR points clouds DSM which solved the plane distortion parameters of DSM.Finally,through these two corrections,the consistency fusion of LiDAR point cloud and RGB image was realized.(b)Aimed at many problems of complex human intervention in the existing classification algorithm,the method of two levels of point cloud classification assisted by vegetation index was put forward,which achieved the division of point clouds into vegetation,ground and buildings.This paper improved the extraction methods of three types of points,lines and faces of the points,and then used the existing CAD software tools to complete the 3d-DLG test of the single building.(c)By unmanned aerial vehicle(UAV)active-passive aerial system integration test,this paper found multi-sensor management shortcomings,put forward a kind of technical route to improve the data quality and expand the application through fusion.The experiment of the 3d-DLG of a small piece of data was completed,and the requirements of 1:2000 was reached,and the feasibility of this technical route was preliminarily confirmed.