地基激光雷达反演树木叶面积参数方法  

Retrieval methods for Tree Leaf Area Parameters Based on Terrestrial Laser Scanning

作　　者：胡容海 邢煜振 HU Ronghai;XING Yuzhen(College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049;Beijing Yanshan Earth Critical Zone National Research Station,Beijing 101408)

机构地区：[1]中国科学院大学资源与环境学院,北京100049 [2]北京燕山地球关键带国家野外科学观测研究站,北京101408

出　　处：《空间科学学报》2023年第6期1160-1175,共16页Chinese Journal of Space Science

基　　金：国家自然科学基金项目(42271393);中国科学院青年创新促进会;中央高校基本科研业务费专项资金项目共同资助。

摘　　要：叶面积指数(Leaf Area Index, LAI)是表征植被冠层结构的核心参数,叶面积指数的间接测量一直是植被遥感的一项重要研究内容。地基激光雷达(Terrestrial Laser Scanning, TLS)以其高效、精细的三维观测能力被广泛用于叶面积指数的反演研究,同时地基激光雷达也为反演更精细的叶面积参数,例如叶面积体密度(Foliage Area Volume Density, FAVD)的三维分布提供了可能性。从方法论角度出发,对基于地基激光雷达反演叶面积参数的主要方法,不同方法的优势、局限性和影响因素进行分析。现有反演方法可分为四类:基于间隙率的方法、基于接触频率的方法、基于计算机图形学理论的方法以及基于生态生理学模型的方法。基于地基激光雷达的叶面积参数反演也从样方尺度叶面积指数向更精细的单木尺度叶面积垂直剖面(Vertical Foliage Profile, VFP)和体素尺度叶面积体密度发展。在此过程中,聚集效应、非均一路径长度和遮挡效应是影响测量精度的重要因素,需要进一步的研究和校正。Leaf Area Index(LAI)is a key parameter that characterizes the structure of vegetation canopies,and the indirect measurement of LAI has always been an important research topic in vegetation remote sensing.Terrestrial Laser Scanning(TLS),with its efficient and precise three-dimensional observation capability,has been widely used for LAI estimation.At the same time,TLS provides possibilities for the inversion of more refined leaf area parameters,such as the three-dimensional distribution of Foliage Area Volume Density(FAVD).This paper reviews the main methods for retrieving leaf area parameters based on TLS from a methodological perspective,discussing their advantages,limitations,and influencing factors.The indirect measurement of leaf area parameters based on TLS can be classified into four categories:the gap fraction-based method,the contact frequency-based method,the computer graphics theory-based method,and the ecophysiological model-based method.These methods differ in theoretical foundations,data organization,etc.,and are suitable for the retrieval of various leaf area parameters at different scales.Among them,the mainstream approach currently relies on the measurement and analysis of gap fraction,and it has evolved into three categories based on different forms of point cloud organization:2D images,pulses,and voxels.Methods based on contact frequency,computer graphics theory,and ecophysiological models are also emerging,providing new avenues for leaf area parameter inversion and can be further optimized to improve the accuracy and efficiency of LAI estimation.Existing methods have basically covered the inversion of various leaf area parameters at different scales.From stand-scale LAI to more refined individual-tree-scale Vertical Foliage Profile(VFP)and voxel-scale FAVD,leaf area parameter inversion based on TLS continues to advance in a refined and three-dimensional direction.In this process,clumping effects,non-uniform path lengths,and occlusion effects are important factors that affect measurement accuracy

关 键 词：叶面积参数 地基激光雷达 间隙率 接触频率 体素 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]