首页|基于ENVISAT/ASAR的神经网络反演人工林叶面积指数研究

基于ENVISAT/ASAR的神经网络反演人工林叶面积指数研究

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对我国西北黑河地区的人工林,进行了基于ENVISAT/ASAR数据构造神经网络的反演杨树林叶面积指数研究.首先,分析了白杨树林、沙枣树林的叶面积指数(LAI)与ENVISAT/ASAR不同极化后向散射系数的相关关系,研究表明人工林的空间分布均一性是影响雷达后向散射和LAI关系的首要因素,其次,不同的入射角对后向散射也具有明显的差异.基于上述分析,通过神经网络算法,利用不同时相、不同入射角的ENVISAT/ASAR雷达影像对白杨树林LAI进行了反演研究,对验证样本、训练样本、所有样本实测值与预测值进行了比较验证,其决定系数R2分别为0.61、0.91和0.82,表明基于ENVISAT/ASAR雷达数据利用神经网络算法反演人工林叶面积指数的可行性.
The Neural Network Algorithm for Estimating Plantation Forest Leaf Area Index based on ENVISAT/ASAR
Based on Neural Network (NN) algorithm,this paper estimated the Leaf Area Index of plantation forests in HEIHE area northwest china using the ENVISAT/ASAR data. Firstly,the relationship between ENVISAT/ASAR microwave backscattering coefficients (σ°) with different polarization, incidence angle and Leaf Area Index (LAI) of White Poplar and Desert Date planted forests were analyzed. The study showed that the homogeneity of plantation forests was the primary factor influencing the relationship. And there were significant difference in the relationship in different incidence angle conditions. Based on the a-nalysis above,the NN algorithm for LAI retrieval was designed using ENVISAT/ASAR with different polarization, incidence angle as input parameters. The study compared the ground measured and predicted LAI for validated data,training data and all data. The determination coefficient reached 0. 61,0. 91 and 0. 82 respectively. And the results showed that there was great feasibility to estimate LAI of plantation forests by NN algorithm using ENVISAT/ASAR data.

Leaf Area Index (LAI)SARBackscattering coefficientENVISAT ASARNeural network

高帅、牛铮、邬明权

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中国科学院遥感与数字地球研究所,遥感科学国家重点实验室,北京 100101

中国科学院大学,北京 100049

叶面积指数 合成孔径雷达 后向散射系数 ENVISAT/ASAR 神经网络

国家重点基础研究发展规划(973计划)国家自然科学基金国家高技术研究发展计划(863计划)遥感科学国家重点实验室青年人才项目

2013CB733405412013452012AA12A304RC12

2013

遥感技术与应用
中国科学院遥感联合中心

遥感技术与应用

CSTPCDCSCD北大核心
影响因子:0.961
ISSN:1004-0323
年,卷(期):2013.28(2)
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