Rural Cadastral Survey And Rapid Mapping Based On LIDAR Technology

LIDAR(Light Detection and Ranging),as a means of efficiently acquiring all kinds of spatial geography data,uses the method of transmitting laser to scan the objects,and it can collect the three-dimensional spatial information quickly.The establishment of the cadastral elements of the two-dimensional or three-dimensional map provides a new means of measurement.At the same time,LIDAR technology has the characteristics of high scanning speed,high precision and low requirement to the environment.It solves the problems of low working efficiency and labor intensity in cadastral survey,and provides a technical basis for the rapid completion of rural Cadastral survey.In order to further accelerate the rural cadastral survey and improve the efficiency and quality of rural cadastral survey,the Xinjiang Uygur Autonomous Region Huo County Sangui Hui Township as the study area,according to the distribution characteristics of rural settlements,the crane equipped with RIEGL VZ-1000 laser radar The scanner performs a fixed scan to obtain point cloud data.Then,through the basic idea of ??the regional growth algorithm,the automatic extraction algorithm of the original point cloud building of the TIN model is used to realize the automatic extraction of the building,and then the Alpha-Shapes algorithm is used to automatically vectorize the top contour of the building Real-time rural areas of the two-dimensional map.The feasibility of the rural cadastral survey and the accuracy of the proposed algorithm are verified by the LIDAR method.The efficiency of the cadastral map and the ownership survey is accelerated,and the semi-automaticization of the cadastral map based on the laser point cloud data is realized.The innovation of this paper is as follows:(1)the first attempt in rural areas using three-dimensional laser radar scanner for cadastral measurements,and according to the geographical environment of Xinjiang rural areas,using a crane equipped with a scanner to scan,to overcome the traditionalcadastral measurement of low efficiency,labor intensity Problem,improve the efficiency of land map and ownership survey.(2)In the aspect of building automatic extraction,this algorithm builds the model to establish the spatial relationship between the point clouds,divides the point cloud by the idea of ??regional growth,generates the object of internal mean value,and then sets the height and variance according to the object Threshold,excluding non-building points,leaving the building point,complete the building extraction.The feasibility of the algorithm is proved by the study of three different types of buildings.(3)In the vectorization of point cloud data,the use of Alpha-Shapes algorithm for building point sets to track the building contours,and achieved good results.The algorithm has a certain degree of adaptability,and studies the relationship between the different a values ??and the contours of different buildings with different densities and shapes,which solves the problem of contour extraction of concave buildings.The outline of the protrusion inside the building,a good solution to the more complex building contours vectorization problem.