Study On The Highway Survey And Design Technology Based On LIDAR

The main content of the highway survey is setting out the pile, vertical-sectional survey, cross-sectional survey. Currently, using GPS RTK, Total Station and Leveling instrument in the construction layout and measurement of vertical-sectional, cross-sectional exist the data collection inefficient, labor-intensive, and great influence by climate, topography, vegetation and the environment of work section. If the electronic flat panel, digital aerial photography or topographic maps and other methods generate digital terrain model (DTM), and then in the DTM interpolation through the interception of vertical-section, cross-section, can effectively reduce the impact of the natural environment, reduce labor intensity and improve road survey of the efficiency and effectiveness. While the highway construction is showing the trends from the plains to the mountains, from the simple to the complex topography area, from the sparse vegetation areas to the dense vegetation areas, which will add to the workload and the difficulty of road measurement and require the higher accuracy of measuring and efficiency. The accuracy of existing data collection methods cannot meet the requirements of road survey, in which case, the proposed highway survey and design based on LIDAR technology, applied research, in order to solve the problems of road survey and design.The article collects a large number of point cloud data of airborne and vehicle LIDAR from the expansion projects of Beijing-Tianjin-Tanggu highway and Beijing-Hong Kong and Macao highway, and to generate the digital model in different conditions, According to LIDAR scanning system of the aviation technical characteristics, we respectively use the flying height of800m and1500m to collect the data of the specified sections, analysis of the flying height, the base station distribution, ground control points, topography, vegetation and other factors on the model law accuracy of digital terrain; the use of vehicle LIDAR scanning system for data collection and the analysis of data accuracy errors, combining with GPS RTK and total station measurement methods of analysis and testing, confirm the accuracy and feasibility of LIDAR scanning technology.According to road plane and determine to the elevation precision tolerances standard, we propose the suitability of aviation and LIDAR scanning technology in new and expanded roads. Meeting the accuracy of digital terrain model, the aviation LIDAR scanning technology achieve the required plane and elevation by reducing the flying height and so on to meet the new and expanded roads. Due to the road network, the accessibility of vehicles is restricted, and the applications of vehicle LIDAR scanning technology in the new highway is also restricted, but in highway expansion it is the ideal way, the security, accuracy, survey efficiency and design requirements and other aspects can meet the requirements.According to the features of the point cloud data processing can be generated orthophoto topographic maps after aviation or the vehicle travelling, combined with the scalability of the plane and elevation information on the orthophoto topographic maps, we establish the road survey process based on LIDAR scanning technology, thereby reducing the survey and design cycle and improving efficiency.Latitude to the digital terrain model technology in Hint CAD system, combining with the point cloud data characteristics and actual needs, we develop the functions of the automatic extraction of point cloud data, the data area searching, the digital-analog simplifying, and solve the difficulties of the LIDAR scanning large volumes of data, operating and applying, and ensure data accuracy standards while simplifying the point cloud data in accordance with the requirements for data accuracy.The model structure is established extracting and simplifying the LAS data of LIDAR scanning in Hint CAD system, and can be called at any time in the design, achieving the effective integration between LIDAR scanning data and existing highway design software.Finally, according to the study and the results, we discuss the application of the LIDAR technology in China’s highway industry from the aspects the efficiency, cost and effectiveness.