基于地基激光雷达数据的林木冠层间隙率和聚集度指数反演
发布时间：2018-07-28 19:12
【摘要】：冠层间隙率是在某一天顶角方向一束光穿过冠层而未被拦截的概率。聚集度指数表征冠层的空间分布集聚情况,描述冠层元素的真实空间分布与随机分布的偏离程度。间隙率和聚集度指数是两个重要的冠层结构参数,可用于相关参数的反演和校正。地基激光雷达技术具有非接触式、高精度、抗干扰能力强等优点,能够为冠层结构参数反演提供有效的技术支持。本文以电子科技大学校园内的玉兰树样方为研究对象,基于地基激光雷达数据,提出了冠层间隙率和聚集度指数反演的新方法,并实现了冠层间隙率和聚集度指数的提取以及冠层聚集情况的研究。此外,本文把数字半球摄影技术作为对比手段。主要内容和结论如下:(1)实验设计与数据预处理:基于地基激光雷达技术和数字半球摄影技术,设计实验方案,分别利用Leica ScanStation C10扫描仪和配备鱼眼镜头的数码相机获取同一玉兰树样方的三维点云数据和数字半球图像,并对点云数据进行配准、去噪等预处理,对半球图像进行分类等预处理。(2)间隙率反演:通过构建三维体元模型、转换坐标系统、半球面投影等过程,建立基于地面高分辨率激光点云数据提取林木冠层间隙率的新方法;基于数字半球摄影技术,对同一研究对象的数字半球图像进行冠层间隙率的提取,并将其研究结果作为对比对象。结果发现,不同体元大小情况下得到的间隙率与从半球图像中提取的间隙率在变化趋势上大致是一致的。当讨论的天顶角范围越小时,利用地基激光雷达数据和数字半球图像得到的间隙率越接近。对于某一确定的天顶角和方位角,体元越小,间隙率越大,反之亦然。(3)聚集度指数反演:以玉兰树冠层点云数据为研究对象,一方面,基于冠层间隙率的对数平均数方法进行聚集度指数的反演;另一方面,结合种群的空间分布型特征,基于SMI(Standardized Morisita's Index)模型研究冠层的聚集情况。基于数字半球摄影技术,利用数字半球图像进行了聚集度指数反演,并将其研究结果作为对比对象。结果表明,不同体元大小情况下得到的各天顶角的聚集度指数与利用半球图像得到的聚集度指数在变化趋势上大致是一致的。对于某一确定的天顶角,体元越小,聚集度指数越大,反之亦然。研究得到的聚集度指数均小于1,SMI均大于0,两个参数均表明了冠层呈聚集分布。
[Abstract]:The canopy clearance rate is the probability of a beam of light passing through the canopy in the apical direction of a given day without being intercepted. The aggregation index represents the spatial distribution and agglomeration of the canopy and describes the deviation between the real spatial distribution and the random distribution of the canopy elements. Clearance rate and aggregation index are two important parameters of canopy structure, which can be used for inversion and correction of correlation parameters. The ground-based lidar technology has the advantages of non-contact, high precision and strong anti-jamming ability, which can provide effective technical support for the inversion of canopy structure parameters. In this paper, a new method for inversion of canopy clearance rate and aggregation index is proposed based on the ground-based lidar data, taking the sample square of Magnolia in the campus of the University of Electronic Science and Technology as the research object. The extraction of canopy clearance rate and aggregation index and the study of canopy aggregation were also carried out. In addition, digital hemispherical photography is used as a contrast method in this paper. The main contents and conclusions are as follows: (1) Experimental design and data preprocessing: based on ground-based lidar and digital hemispheric photography, the experimental scheme is designed. Leica ScanStation C10 scanner and digital camera equipped with fish-eye lens were used to obtain 3D point cloud data and digital hemispherical image of the same magnolia tree, and the point cloud data were pre-processed, such as registration, denoising and so on. The classification of hemispherical images is preprocessed. (2) clearance rate inversion: a new method for extracting canopy clearance rate based on surface high resolution laser point cloud data is established by constructing 3D volume element model, transforming coordinate system, and semi-spherical projection. Based on digital hemispheric photography, the crown gap rate of the same object was extracted and the results were compared. The results show that the gap rate obtained with different volume size is approximately consistent with the gap rate extracted from hemispherical images. The smaller the range of zenith angle discussed, the closer the gap rate obtained from ground-based lidar data and digital hemispheric image. For a certain zenith angle and azimuth angle, the smaller the volume element, the larger the clearance rate, and vice versa. (3) the inversion of aggregation index: taking the cloud data of magnolia canopy as the research object, on the one hand, Based on the logarithmic average method of canopy gap rate, the aggregation index is inversed. On the other hand, combining the spatial distribution characteristics of the population, the SMI (Standardized Morisita's Index) model is used to study the aggregation of the canopy. Based on digital hemispheric photography, the aggregation index inversion of digital hemispheric images is carried out, and the results are compared. The results show that the aggregation index of the zenith angles obtained with different volume sizes is approximately consistent with that obtained from hemispheric images. For a given zenith angle, the smaller the volume element, the greater the aggregation index, and vice versa. The indexes of aggregation are all less than 1 SMI > 0, and the two parameters indicate that the canopy is clustered.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S758;TN958.98
本文编号：2151313
[Abstract]:The canopy clearance rate is the probability of a beam of light passing through the canopy in the apical direction of a given day without being intercepted. The aggregation index represents the spatial distribution and agglomeration of the canopy and describes the deviation between the real spatial distribution and the random distribution of the canopy elements. Clearance rate and aggregation index are two important parameters of canopy structure, which can be used for inversion and correction of correlation parameters. The ground-based lidar technology has the advantages of non-contact, high precision and strong anti-jamming ability, which can provide effective technical support for the inversion of canopy structure parameters. In this paper, a new method for inversion of canopy clearance rate and aggregation index is proposed based on the ground-based lidar data, taking the sample square of Magnolia in the campus of the University of Electronic Science and Technology as the research object. The extraction of canopy clearance rate and aggregation index and the study of canopy aggregation were also carried out. In addition, digital hemispherical photography is used as a contrast method in this paper. The main contents and conclusions are as follows: (1) Experimental design and data preprocessing: based on ground-based lidar and digital hemispheric photography, the experimental scheme is designed. Leica ScanStation C10 scanner and digital camera equipped with fish-eye lens were used to obtain 3D point cloud data and digital hemispherical image of the same magnolia tree, and the point cloud data were pre-processed, such as registration, denoising and so on. The classification of hemispherical images is preprocessed. (2) clearance rate inversion: a new method for extracting canopy clearance rate based on surface high resolution laser point cloud data is established by constructing 3D volume element model, transforming coordinate system, and semi-spherical projection. Based on digital hemispheric photography, the crown gap rate of the same object was extracted and the results were compared. The results show that the gap rate obtained with different volume size is approximately consistent with the gap rate extracted from hemispherical images. The smaller the range of zenith angle discussed, the closer the gap rate obtained from ground-based lidar data and digital hemispheric image. For a certain zenith angle and azimuth angle, the smaller the volume element, the larger the clearance rate, and vice versa. (3) the inversion of aggregation index: taking the cloud data of magnolia canopy as the research object, on the one hand, Based on the logarithmic average method of canopy gap rate, the aggregation index is inversed. On the other hand, combining the spatial distribution characteristics of the population, the SMI (Standardized Morisita's Index) model is used to study the aggregation of the canopy. Based on digital hemispheric photography, the aggregation index inversion of digital hemispheric images is carried out, and the results are compared. The results show that the aggregation index of the zenith angles obtained with different volume sizes is approximately consistent with that obtained from hemispheric images. For a given zenith angle, the smaller the volume element, the greater the aggregation index, and vice versa. The indexes of aggregation are all less than 1 SMI > 0, and the two parameters indicate that the canopy is clustered.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S758;TN958.98
【参考文献】
中国期刊全文数据库 前10条
1 耿君;田庆久;涂丽丽;范渭亮;王晓菲;;树冠尺寸对冠层间隙率和聚集度指数的影响[J];遥感学报;2016年06期
2 朱高龙;;2000～2013年中国植被叶片聚集度系数时空变化特征[J];科学通报;2016年14期
3 樊琦;姚顽强;陈鹏;;基于Cyclone的三维建模研究[J];测绘通报;2015年05期
4 尹高飞;柳钦火;李静;曾也鲁;徐保东;;树冠形状对孔隙率及叶面积指数估算的影响分析[J];遥感学报;2014年04期
5 李丹;庞勇;岳彩荣;;地基激光雷达在森林参数反演中的应用[J];世界林业研究;2012年06期
6 崔要奎;赵开广;范闻捷;徐希孺;;机载Lidar数据的农作物覆盖度及LAI反演[J];遥感学报;2011年06期
7 朱高龙;居为民;陈镜明;柳艺博;朱敬芳;邢白灵;;利用POLDER数据验证MODIS BRDF模型参数产品及Ross-Li模型[J];遥感学报;2011年05期
8 Nguyen Tien Thanh;刘修国;王红平;于明旭;周文浩;;基于激光扫描技术的三维模型重建[J];激光与光电子学进展;2011年08期
9 彭焕华;赵传燕;冯兆东;许仲林;;利用半球图像法提取植被冠层结构特征参数[J];生态学报;2011年12期
10 陈林;廖文波;杨志松;张阳;何娅;周材权;;高原鼢鼠土丘空间分布研究[J];西华师范大学学报(自然科学版);2010年02期
中国博士学位论文全文数据库 前2条
1 朱高龙;植被叶面积指数与叶片聚集度系数遥感反演方法研究[D];南京大学;2011年
2 焦子锑;利用MODIS BRDF和反照率产品进行地表特性的研究[D];北京师范大学;2008年
中国硕士学位论文全文数据库 前3条
1 彭博;激光三维扫描点云数据的配准研究[D];天津大学;2011年
2 周华伟;地面三维激光扫描点云数据处理与模型构建[D];昆明理工大学;2011年
3 潘桂颖;基于半球摄影法的水稻冠层结构参数测量与反演[D];浙江大学;2011年
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