Study On The Vegetation Structure Of Lower Canopy Layers In Wooded Area Using LIDAR Data

Airborne LIDAR (Light Detection And Ranging), is a new technologywhich develop rapidly, and has become the important technical of earthobservation from space. Compare with others mapping and remote sensingtechnologies, airborne LIDAR’s main advantage is which can getting3Dposition of the terrain quickly and directly. In recent years, Airborne LIDARtechnology has been applied to main different areas, such as forestmanagement, unban mapping. In wooded area, the laser beam send by LIDARsystem can penetration the vegetation to reach the ground surface, in thisprocess, multi-echo will be returned. Therefore, using this technology, notonly can get the3D position data of the crown surface, but also can analysisthe vertical structure of vegetation. This paper focused on extraction DEMand analysis forest vegetation vertical structure.The achievement and innovation of this thesis are listed bellow:1. In order to get a High-precision digital elevation model (DEM). In thispaper, a new method is proposed and implemented, which is characterized byits combination of adaptive quadtree-based processing with common iterativeinterpolation and filtering methods. It was proved to meet the requirements ofnational cartography standard on terrain mapping with large scale. Also, goodefficiency of adaptive quadtree-based iterative filtering algorithm was verifiedas well as its adaptation for processing high density LIDAR data over a largeextent.2. In this study, the total1000field measurement points are collected byhigh-precision total-station, and600points of them are used as the checkpoints. Digital elevation models (DEM) of wooded and undulating hill areasare derived from airborne LIDAR data, and they have proved to be in goodaccordance with check points of terrain surfaces.3.Considering the requirements of analysis the vertical structure of forestvegetation, this paper proposed an analysis model based on original LIDAR points. The results of the model analysis have been proved by the surveyresults about status of management and non-management area. It can be usedfor the vertical structure of vegetation.4. Using analysis model divided the forest vegetation into upper, middleand lower layers based on the winter and summer LIDAR data points. Therelationship between the results value of different layer and DEM error isanalysis. The results show that between them there is no obvious correlation,but the intensity of vegetation has significant effect to the accuracy of digitalelevation model.5. The design and development about the related software has been done.The demonstration work was applied in test area to analysis vertical structureof vegetations.