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Leaf Area Idex Inversion Of The Broadleaf Shrub Based On The Synergy Of The Hyperspectral And Terrestral LiDAR Data

Posted on:2017-01-28Degree:MasterType:Thesis
Country:ChinaCandidate:J X HuiFull Text:PDF
GTID:2180330485988220Subject:Surveying the science and technology
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The leaf area index(LAI), an important parameter of vegetation canopy, affects the photosynthesis, transpiration, and precipitation interception of the physiological process, which is an important indicator of the plant growth also. The Inversion of LAI that is important significance to the ecological is a hotspot and difficulty in the remote sensing field. Also it is the need of ecological environment assessment and management.The traditional single remote sensing data which is limited by the way of obtaining, can not describe the vegetation information quickly and completely. In this thesis, we take full advantage of the two kinds of data by the combination of the Hyper-spectral and the LiDAR, which is effective in the retrieval of vegetation parameters. The hyperspectral data with abundant spectral information, has gradually become the main data source of the inversion of vegetation parameters. The LiDAR which has the function of playback the true scene can describe the vegetation efficiently and accurately. The synergy with the spectral imaging and the LiDAR data, realistic description of vegetation canopy structure, will improve the precision of vegetation parameters’ inversion further. And the study will make the vegetation remote sensing extend from plane to three-dimensional, which is a useful attempt and exploration for the research of the integration of the ground, the airborne and the satellite. In Xishuangbanna and the University of Electronic Science and technology, we select the tea tree and the French Holly as the the research object with the the imaging spectrometer and Terrestrial LiDAR. With the obtained data,we inversion the LAI cooperatively.The main work and conclusions of the study are as follows:(1) The design of the ground synergy experiment and the acquisition of the data. Design the experimental method of the inversion of LAI by the ground data. We study the methods of obtaining the broadleaved shrub’ hyperspectral data and laser point cloud with using the SOC710 VP imaging spectrometer and Leica scanstation C10 3D laser scanner collaboratively. And, the auxiliary data obtained from the auxiliary experimental instrument verify the imaging spectrometer data and the LiDAR data. The results show that two kinds of collaborative data are accurate and reliable.(2) The band selection of hyperspectral and the extraction of shrub structure parameters from the LiDAR data. According to the characteristics of the two kinds of data, we study the methods of denoising. Because the input parameters of the physical model are many and difficult to obtain, the processing of the two kinds of data are studied in this thesis for the needs of the inversion of LAI in the physical model. For the imaging spectral data, we study the inversion of hyperspectral reflectance data, the selection and optimization of the band. And for the lidar data, we study the method of efficient extraction of structure parameters.(3) The present widespread canopy reflectance model are analyzed. We select the GeoSail model as the inversion model according to the characteristics of shrub in the study area.And based on the characteristics of the hyperspectral and the lidar data, we achieve the inversion of LAI and improve the precision of inversion. With the Geosail model and the look-up table algorithm, The LAI of the broadleaf shrub was successfully retrieved in December 2013 and October 2015. Finally, with comparison between the simulation data and the measurement shows that the simulation results are in good agreement with experimental data. For the tea, the correlation coefficient of the measured values and inversion value reached to 0.70, RMSE=0.33. And for the sparse Holly bush the correlation coefficient of the measured value and inversion value reached to 0.83, RMSE=0.32. The experimental results show that the simulation are consistent with the measured value.The experiment is proved that the GeoSail model can be applied to the low shrubs.And it is the feasibility of the experiment for the application of UAV remote sensing platform.
Keywords/Search Tags:Hyperspectral, Terrestrial LiDAR, Leaf area index, Inversion
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