Data Processing And Valley-ridge Feature Extraction Based On Airborne LIDAR Technique

The airborne Light Detection and Ranging (LIDAR) is a kind of new technique which isdeveloped gradually from the end of20thcentury, can be used in many areas such as earthscience and planetary science. It is a kind of active geometric acquisition system, it isintegrated with a collection of laser technology, dynamic pose measurement technology andhigh precision differential GPS technology. This technology obtains the real3-D spatialinformation and makes the great breakthrough. It brings a brand-new technological means forobtaining high space-time resolution information.In recent years, with the development of related technologies and the expansion of thesocial needs, airborne LIDAR which represents a new development direction in the field ofearth observation, makes data acquisition, processing automation and intellectualization.Compared with the rapid development of hardware technology, the post-processingalgorithms(such as automatic filtering and classification) of LIDAR point cloud data are stillin the stage of being researched, and need to be further studied.This paper systematically discusses the airborne LIDAR system and the theories andtechniques of data post-processing. The main research contents are as follow:1. Reviewing the development history and current research of data processing of LIDARsystem, Summarizing the characteristics and main application fields of airborne LIDARtechnology.1. Introduce the standard data format of the LIDAR——LAS format. Compare withseveral versions.2. Through analyzing the features of gross error distribution, LIDAR original point clouddata can be divided into extreme outliers, outlier clusters and isolated points. On this basis, thegross error can be eliminated hierarchically.3. The common methods and algorithms to filter LIDAR data are reviewed andcompared. Based on the TerraSolid series software and LDS information processing-systemself-developed by instrument of geological and mapping in Fujian Province, this paper introduces airborne LIDAR data pose-processing and production technique of airborneLIDAR data.4. Ridge and valley characteristic line is very helpful of DEM accuracy control. Based onthe research of the differential geometry theory, combined with local polynomial fitting,attempting to put forward an algorithm of extracting ridge valley feature line in mountainarea.