摘要
基于冬小麦返青期至乳熟期8次采样的地面光谱数据和收割时的产量数据,首先,利用光谱反射率与产量进行了统计分析,可见光波段的光谱反射率与产量在起身后期才达到稳定的显著负相关水平;近红外波段的光谱反射率与产量在所有生育期都表现出稳定的显著正相关;短波红外波段的光谱反射率与产量在进入灌浆期后才达到稳定的显著负相关水平。其次,根据冬小麦冠层光谱的波形特征,利用近红外波段890nm反射峰、980nm和1200nm两个弱水汽吸收谷、短波红外1650nm和2200nm反射峰,设计归一化差值光谱指数,并与冬小麦产量进行相关分析,结果表明:利用上述波段组合定义的归一化差值光谱指数与产量在各个生育期都达到了显著或极显著相关水平,而归一化差值植被指数(NDVI)与产量间的相关在营养生长阶段不显著。最后,以(890nm,1200nm)弱水汽吸收光谱指数为例,建立了各个生育期的产量预报模型,为实现冬小麦营养生长期长势监测与更早、更可靠的产量预报提供了依据。
The coefficients of correlation between yields and spectral reflectances in eight different growth stages were first calculated. The statistical results show that yield is positively correlative with spectral reflectance in NIR bands for all the growth stages, negatively correlative in visible bands from late jointing stage, and also negative correlative in shortwave-infrared bands from seeding stage. Second, the normalized difference spectral indices combined by [890 nm, 1200 nm], [890 nm, 980 nm], [890 nm, 1650 nm], [890 nm, 1650 nm] and [890 nm, 2200 nm] are significantly correlative with yields in all the 8 growth stages, which is better than NDVI. Finnally, the remote sensing models in different growth stages for winter wheat yield were built by [890 nm, 1650 nm] weak water absorption index.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2004年第1期172-175,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家发展计划委员会"北京精准农业示范工程"项目(A00300100584)
北京市自然科学基金重点项目(6021002)资助
