Research On Point Cloud Visualization Of Airborne Dual-frequency Lidar

Traditional methods of surveying and mapping which to obtain geographic information takes a long time and the sampling frequency is very low.At present,with the development of hardware and software technology,this thesis expect the precision of geographic information data can reach the centimeter level all over the world.The progress of laser radar technology makes us get geographic information data more convenient and accurate.Laser radar system mostly devoted to the research and development of the laser detector which is large area and high sensitivity in foreign laboratories.Laser radar technology can not only collect multi-dimensional data actively and accurately,but also it is a kind of data acquisition mode which is continuous and intensive.So the laser radar technology become the hotspot of surveying and mapping technology gradually.After knowing the history of LIDAR and referring to the research status at home and abroad.In this thesis,I developed the corresponding processing software on the basis of the characteristics of the point cloud of the LIDAR system,and made a prospect based on the thesis.The thesis is based on the tutor of the State Oceanic Administration project researching the dual-frequency marine laser radar system.Based on the present situation of dual-band laser radar,this thesis proposes a double-frequency laser using the scanning model of combination of point scanning and line scanning to make the scanning method more efficient.In this thesis,the design of the optical scanning system of this dual-frequency laser radar system is introduced in detail.In order to obtain a larger single laser pulse detection area under the same horizontal resolution,this thesis adopt the methods of splicing of 1 × 176 fiber receiver array and 8 1 × 25 linear array APD instead of large array of APD detector array receiver to improve the foreign large-scale array of APD detectors on the embargo situation.The core work of this thesis is based on the whole airborne dual-frequency laser radar system characteristics of point cloud data processing and the researching of visualization software.In this thesis this thesis have completed the design of the human-computer interaction interface,the point cloud single-band and the multi-flight data entry module,the coordinate transformation module and the point cloud drawing module.According to the system requirements to design a proprietary point cloud data format to improve the software to run the memory consumption and interpolation for point data has been improved.Secondly,the results of this experiment show that the final results of the software are the same as those of the manual verification,which proves that the coordinate conversion function of the software is completely normal.Finally,on the basis of the above description of the mapping this thesis completed the multi-flight data stitching experiment.The software on the development of domestic Lidar data processing software have some reference value.