Study On Leaf Area Index Of Living Leaves Based On Ground Laser Scanning

Stumpage’s leaf is the main place that it interacts with the external environment, and its Leaf Area Index measurements on growth, photosynthesis and respiration, as well as the amount of vegetation carbonization of plant are of great significance. However, the traditional method of measuring Leaf Area Index consumes a lot of manpower and time, and most of the target object will produce an unrecoverable destructive measurement. For faster and more convenient, non-destructive measurement of Leaf Area Index determination of stumpage,this research adopts the Laser Scanning collecting point cloud data from dense plants, the use of image processing can calculate effective Leaf Area Index, this experiment selectes two aspects of plant canopy and stand。(1) Leaf Area index of the single stumpage: in order to accurately get the Leaf Area Index, this study proposes a algorithm based on projection and the calculation method of Geodesic Active Contour Model. In this part, on the ground first Laser scanner(Terrestrial Laser Scanning, the TLS) trees get point cloud data pass after a certain proportion zoom in a ball on the surface, and then through the Stereographic Projection and Lambert Azimuthal Equal-Area Projection, area on spherical images is projected onto a plane, with the help of the concept of geography latitude lines on the characterization of different heights leaf Zenith Angle, Leaf Angle obtained through statistical methods, and then using the Geodesic Active Contour Model to foliage part projection image segmentation, for porosity. According to the law of Beer-Lambert can calculate effective Leaf Area Index(LAIe); Actual Leaf Area Index(LAIa) access is through hierarchical processing, effectively solve the problem of overlapping leaves.(2) A piece of forest canopy Leaf Area Index calculation: in order to accurately obtain the canopy Leaf Area Index, this study proposes a based on Fish eye camera and the calculation method of the ground laser radar hemisphere of image. To order tetraodontiformes camera images with the help of the concept of geography latitude lines on the Leaf Zenith Angle to characterize different heights, and Leaf Angle obtained through statistical methods, analysis of hemisphere porosity image capture. According to the law of Beer- Lambert can calculate effective Leaf Area Index(LAIe); Actual Leaf Area Index(LAIa) acquisition is addressed by the cluster coefficient of canopy. Laser scanner for the canopy of point cloud data by certain proportion zoom in a ball on the surface, and then through the Stereographic Projection and Lambert Azimuthal Equal-Area Projection on spherical images projected onto a plane, in order to get similar hemisphere image.(3) The thesis finally, will receive the data compared with the measured real Leaf Area Index, to prove the accuracy and feasibility of the method.