The Research About High Accuracy DEM Obtained From The Fusion Point Cloud Of Domestic Airborne LiDAR Point Cloud And Images

Airborne LiDAR as a kind of fast,real-time and efficient new technology for acquiring geospatial information,has played a huge role in promoting the development of the traditional surveying and mapping career.The studies of this thesis are around the establishing the model of location for domestic airborne LiDAR AP-3500,the calibration of Integrated error,the fusion of the point cloud and image,with the purpose to improve positioning accuracy.At last,this thesis validates the accuracy of fusion point cloud.The main content of this paper is as follows:(1)The research of the LiDAR system integrate and the establishment of error correction model.This thesis first provides a brief introduction to the composition of domestic LiDAR system,and elaborates the principle of inertial navigation system and how the LiDAR point cloud measures,at the same time,in order to acquire the accurate 3-D coordinate,This thesis establishes separate coordinate system in the system's components and then find the deviations of the coordinate systems' angular and location.(2)The calibration of Integrated error.This thesis builds the calibration mode to obtain the lens distortion coefficient and elements of interior orientation,and completes the calibration for platform of double cameras.At the same time.This thesis builds the calibration mode of the laser scanner by the angle measurement and range measurement,and completes the calibration of integrated error containing POS,LiDAR system and camera system.(3)The study of data processing.This thesis get the method of date processing which makes the information of images relatively little lost by experiment and processes point cloud with the assist of images' information.Whereafter,this thesis successfully fuses the point cloud and images,then makes the fused point cloud contains not only the initial information of intensity.reflecting intensity,number of reflection waves,3-D coordinate,but also the information of spectrum.All of this information is used to filter and classify the point cloud,and then ground points filtered are used to construct the Surface triangulation and to construct the DEM.(4)The precision verification and analysis of the DEM.Under the supportive program of national administration of surveying,mapping and geoinformation,the flight test was carried out in Weidong District.Pingdingshan City.Henan Province.The point cloud got from the test is fused with images obtained at the same time,and the fused point cloud are used to produce DEM after filtered and classified.The plane and elevation accuracy of the point cloud is verified by the difference between the measure centre and fitting centre of the square target placed in the testing areas,and finally the accuracy of DEM is evaluated by using checkpoints.