摘要
利用高光谱技术可估测水稻冠层叶绿素含量,为水稻的长势遥感监测与农艺决策提供科学依据.基于地面实测水稻叶片光谱数据,提出了一种粗糙集属性简约和支持向量回归相结合的叶绿素反演方法,解决了植被光谱指数相关性高易造成计算冗余以及降低水稻叶片叶绿素高光谱反演效率的问题.首先选择18个与水稻叶绿素含量相关性较大的植被光谱指数作为因变量,利用粗糙集约简植被指数数据空间得到含有6个植被光谱指数的简约核;然后采用支持向量回归方法反演叶绿素含量.基于全部指数反演及基于简约核指数反演的R2分别为0.8586与0.850 6.因此,该方法与采用全部指数进行反演的结果相比,不但具有相当的反演精度,而且有效缩短了反演算法步骤及时间,为大数据处理提供了新的技术方法.
The rice canopy chlorophyll content can be estimated by using the hyperspectral technique for rice growth monitoring and agronomic decision-making.This paper presents a chlorophyll estimation method based on rough set attribute reduction and support vector regression （SVR） using ground spectral data to solve the problem of data redundancy and low retrieve rate caused by high correlation between vegetation indices.Eighteen hyperspectral indices are selected as variables to estimate the chlorophyll content of rice canopy.The data space is reduced using the rough set algorithm.The SVR algorithm is then introduced to estimate the chlorophyll content.There are six indices reserved in the reduced kernel after attribute reduction.R2 of retrieval results based on all indices and reduced kernel are 0.858 6 and 0.850 6 respectively.The proposed method can achieve an accurate forecasting rate based on all feature attributes,and reduce processing steps and estimation time.It provides a new method for big data processing.
出处
《应用科学学报》
CAS
CSCD
北大核心
2014年第4期394-400,共7页
Journal of Applied Sciences
基金
国家自然科学基金(No.41001214/D0106)资助
关键词
粗糙集
植被指数约简
高光谱遥感
叶绿素含量反演
支持向量回归
rough set
vegetation indices reduction
hyperspectral remote sensing
chlorophyll content retrieval
support vector regression （SVR）
作者简介
通信作者：刘湘南，教授，博导，研究方向；遥感应用模型、地球空间信息分析，E-mail：liuxncugb@163．com
通信作者：赵冬，博士，研究方向：环境遥感应用，E—mail：zhaodong@irsa．ac．cn；
