摘要
用ASD FieldSpec光谱仪实测棉花冠层不同生育时期的高光谱数据,同期获取棉花叶面积指数(LAI)和地上干物质积累量(Above-ground Dry Matter Accumulation,ADMA)。分析棉花冠层反射光谱与棉花LAI、地上部干物质积累量(ADMA)的相关关系,分析结果表明,反射光谱数据与棉花LAI、ADMA的相关系数的最高值分别发生在783nm(r=0.6394**)和766nm处(r=0.6287**);对反射光谱数据进行统计分析,建立了基于比值植被指数(RVI)和归一化植被指数(NDVI)的5种函数形式的棉花LAI、ADMA估测模型。经检验,基于RVI的估测模型具有较高的精度;对一阶微分光谱数据与棉花LAI和ADMA的逐步回归相关分析表明,敏感波段分别发生在736nm(r=0.6769**)和742nm处(r=0.6847**)。由736nm、742nm波段处的微分数值建立的LAI和ADMA线性回归估测模型,R值均达到了1%极显著的检验水平,说明一阶微分光谱敏感波段的数值,对棉花LAI和ADMA具有一定的估算能力。
Hyperspectral data of cotton canopy were measured with ASD FieldSpec during different growth stages, and simultaneously, leaf area index（LAI）, above-ground dry biomass accumulation（ADMA） were acquired. The correlations between the reflective spectra data and cotton canopy LAI, ADMA were analyzed, respectively. The result indicated that the maximum correlation coefficients between reflective spectra data and LAI, ADMA of cotton were occurred at wavelength 783 nm（r=0. 6394^＊＊） and 766 nm（r=0. 6287^＊＊）, respectively. Reflective spectra data were statistically analyzed to establish five function modelings of LAI, ADMA of cotton, based on ratio vegetation index（RVI）, and normalized difference vegetation index（NDVI）. The RVI modeling has a higher precision. According to correlation analysis between the first derivative spectra data and LAI, ADMA of cotton, the sensitivity wavelength has take placed at 736 nm（r=0. 6769^＊＊） and 742 nm（r=0. 6847^＊＊ ）,respectively. Using derivative spectra value of wavelength 736 nm and 742 nm to establish the linear regression modelings of LAI and ADMA, all reached 1% significant level. It showed that value of sensitivity wavelength of the first derivative spectra has certain estimating capacity for LAI and ADMA of cotton.
出处
《棉花学报》
CSCD
北大核心
2008年第3期217-222,共6页
Cotton Science
基金
国家自然科学基金(30460060)和(30060039)
关键词
棉花
高光谱
植被指数
叶面积指数
地上干物质积累量
cotton
hyperspectral
vegetation index
leaf area index
above-ground dry matter accu-mulation
