Applied Research On Airborne LiDAR Technology In Railway Cross-sections Extraction

As a new technology of space measurement, airborne Light Detection AndRanging(LiDAR) can obtain three-dimensional GIS data quickly and efficiently，which has caused surveying and mapping，and other related industries much interest.In China, the railway construction is developing rapidly. Especially，high standardHigh-speed Rail and Passenger Line are under construction. However，railway surveyhas been facing some problems, such as short surveying period、heavy task、complexterrain，and so on. Airborne LiDAR technology can quickly obtain a wide range andlarge quantities of precious three-dimensional geographic information，which cangreatly meet the demand of data for railway construction，that is why airborne LiDARis widely used in railway industry. Compared to traditional means of measurement，this way which is based on airborne LiDAR data to generate DEM，then to extractrailway profile-sections has much more advantages，because it can extract quantitiesof railway profile-sections efficiently.In this paper，the author combined with the project of LiDAR to analyze itsapplication in railway profile-sections extraction.The main content is as follows：For the first，this paper systematically introduces the research status of airborneLiDAR technology from hardware and software development，as well as point cloudsfiltering algorithms. It also analyzes how does traditional measuring techniquesextract profile-sections in railway. In addition, the paper also makes a systematicintroduction on the airborne LiDAR system composition and working principle, andthen analyzes its data characteristics and technical advantages.This paper studies the airborne LiDAR technique in railway profile-sectionsextraction in the working principle and technical route，and makes precision analysisof the railway profile-sections and feasibility studies through experiment based onLiDAR data. The airborne LiDAR point clouds filtering is discussed in detail.However，the mainstream filtering algorithms and their characteristics are analyzed.Finally,in view of the influence of different filtering thresholds，the author alsocarry an experiment of filtering thresholds selection to analyze the influence of iterative angle and iterative distance on different terrain levels and different coveragesof vegetables.