多光谱与激光雷达相结合的森林叶面积指数垂直分层分布反演研究

项目名称： 多光谱与激光雷达相结合的森林叶面积指数垂直分层分布反演研究

项目编号： No.41201345

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地理学

项目作者： 高帅

作者单位： 中国科学院遥感与数字地球研究所

项目金额： 25万元

中文摘要： 森林生态系统通常由林、灌、草等多种植被构成,呈现一定的垂直分层分布特征，因此其叶面积指数也呈垂直分层分布，这种分布对于植被的光能利用效率具有重要影响。在这种情况下，利用被动光学反演叶面积指数具有较大的局限性，本研究拟结合垂直方向多光谱和激光雷达回波信息进行垂直分层分布研究。基于森林辐射传输模型进行树木、灌木两层特征森林群落的回波建模，模拟激光雷达回波与不同层植被叶面积指数和其他参数的关系，比较激光雷达和多光谱反射率对不同层植被参数的敏感性差异，结合实测数据，研究分层叶面积指数反演的主被动协同机理。同时，开展野外试验，利用实测森林参数及主被动遥感数据，进行森林空间结构分布及象元尺度归一化研究，结合模型模拟实现主被动遥感的误差分布规律的模拟，驱动协同模型进行模型驱动及优化算法的选择。最后，通过比较分析，建立反演算法，用实测数据进行森林叶面积指数垂直分层分布的反演及验证。

中文关键词： 激光雷达；叶面积指数；高光谱；垂直分布；协同反演

英文摘要： For the forests community, there are many different types of plants in the vertical direction, including trees, shrub, and grass. And the leaf area index (LAI) which plays an important role in the photosynthesis of plant is also vertical distributed along the height. Considering the retrieval limitation relying only on solar illumination, the combination of multispectral and active full-wave lidar will be studied for the retrieval of LAI vertical distribution in the forests with two layers architecture. In the study, the forest radiative transfer model will be utilized for modeling laser signal intensity of every layer. Then, the sensitivity analysis of laser intensity to LAI and other parameters in different layers will be carried out. Comparison with that of multispectral result, the simplified two-layer synthetic model will be established. Then using measurement result of forests and remote sensing data, the forest spatial structure distribution and normalization of multispectral and lidar wave in one pixel will be studied. Combining with the model simulation, the error distribution law will be set up to choose the optimal algorithm. Finally, the algorithm will be built and tested using the remote sensing data and validated with ground measurements data in forests.

英文关键词： lidar；leaf area index；hyperspectrum；vertical distribution；synergy retriveval