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摘要聚集度系数是描述植被结构的重要的参数，它表征植被冠层空间分布的聚集程度，可以用来描述冠层中阴影叶和光照叶的数量，是各种地表模型实现的输入参数。目前500米分辨率的全球聚集度系数图已经通过多角度遥感数据获得，但精度还不能满足对各种应用的需求。51819
本文为了获取500米分辨率的聚集度系数分布图，利用2012年和2013年中国东南部地区的MODIS BRDF产品数据和地表覆盖产品数据,采用Ross-Li模型的改进模型Ross-Li-C模型模拟在观测天顶角和太阳高度角为45度情况下的地表反射情况，获取植被的热点和暗点的反射率，进一步获取归一化热暗点信息指数（NDHD，Normalized Difference between Hotspot and Darkspot），由于NDHD和聚集度系数（Clumping Index或Ω）之间存在线性关系，可表示为 ，根据它们之间的关系，从而获得聚集度系数，并绘制研究区的500米分辨率的聚集度系数分布图。分析比较2012年热点反射率，暗点反射率和NDHD的变化趋势发现，受植被季节变化特征影响，热点和暗点发射率在前八个月呈上升趋势，之后值呈下降趋势。对于不同植被覆盖类型，不同季节其冠层机构特征差异大，所以NDHD的变化呈现出较大不同，但都在四月份和八月份呈现出最大值。
该论文有图8幅，表2个，参考文献30篇。
毕业论文关键词：聚集度系数 归一化热点暗点指数 中等分辨率成像光谱仪 时间序列分析
Clumping Index Retrieval From the MODIS BRDF Product
Abstract
Clumping Index is an important parameter of describing vegetation structure, it characterizes the clumping degree of the spatial distribution of vegetation canopy, also can be used to calculate the number of sunlit and shaded leaves and is a variety of surface model input parameters. Now 500 meter resolution of the global foliage clumping index figure has been obtained from multi-angle remote sensing data, but it can't meet the precision demand for a variety of applications.
In this paper, for the sake of get the distribution figure of 500 meter resolution, MODIS BRDF and land cover product data are used which cover the southeast of China in 2012 and 2013. The vegetation reflectance of hot spots and dark spots were obtained using the Ross-Li model of improved model Ross-Li-C model simulation in observing zenith Angle and altitude of the sun Angle of 45 degrees. To further obtain Normalized Difference between Hotspot and Darkspot (NDHD). There is a linear relationship between NDHD and clumping index and can be expressed as , according to the relationship between them, to get the clumping index and draw distribution figure of 500 meter resolution in the study area. Analysing and comparing the trend of hotspot, darkspot and NDHD found that hotspot and darkspot were on the rise in the first eight months, after a downward trend because of the affect of seasonal variation characteristics of vegetation. For different vegetation types, the canopy institution characteristic is difference in different season, so the change of NDHD present a big different, but are maximum in April and August.
The paper has 8 figures, 2 tables, 30 references.
Key Words: clumping index NDHD MODIS time series analysis
目 录
摘要 III
Abstract IV
表清单 VI
变量注释表 VII
1 绪论 1
1.1 选题依据及研究意义 1
1.3 研究内容和技术路线