In this paper, a new method for canopy water content (FMC) estimation for highly vegetated surfaces- shortwave infrared perpendicular water stress index (SPSI) is developed using NIR, SWIR wavelengths of Enhanced Them...In this paper, a new method for canopy water content (FMC) estimation for highly vegetated surfaces- shortwave infrared perpendicular water stress index (SPSI) is developed using NIR, SWIR wavelengths of Enhanced Thematic Mapper Plus (ETM+) on the basis of spectral features and distribution of surface targets with different water conditions in NIR-SWIR spectral space. The developed method is further explored with radiative transfer simulations using PROSPECT, Lillesaeter, SailH and 6S. It is evident from the results of validation derived from satellite synchronous field measurements that SPSI is highly correlated with FMC, coefficient of determination (R squared) and root mean square error are 0.79 and 26.41%. The paper concludes that SPSI has a potential in vegetation water content estimation in terms of FMC.展开更多
为提高返青期-拔节期-开花期-灌浆期不同覆盖条件下小麦冠层含水量的遥感反演精度,综合分析基于Nir-Red和Nir-Swir光谱特征空间开展作物含水量监测的优势与局限,利用垂直干旱指数(perpendicular drought index,PDI)和短波红外垂直失水指...为提高返青期-拔节期-开花期-灌浆期不同覆盖条件下小麦冠层含水量的遥感反演精度,综合分析基于Nir-Red和Nir-Swir光谱特征空间开展作物含水量监测的优势与局限,利用垂直干旱指数(perpendicular drought index,PDI)和短波红外垂直失水指数(shortwave infrared perpendicular water stress index,SPSI)的比值形式,构建了一种基于近红外-红波段-短波红外(Nir-Red-Swir)三波段光谱特征空间的垂直植被水分指数(three-band perpendicular vegetation water index,TPVWI)。结果表明,在不同生育时期,TPVWI与小麦冠层含水量(vegetation water content,VWC)均具有显著相关关系(P<0.01),且对植被含水量的敏感性优于PDI、作物水分监测指数(plant water index,PWI)、SPSI和NDVI 4种植被指数,且在反映小区域内小麦冠层含水量的时空趋势上有较好的表征能力。对比地面实测数据,利用TPVWI建立的作物含水量估测模型的预测精度较高,r与RMSE分别为0.763和2.296%,说明利用综合Nir-Red-Swir三波段光谱空间特征的植被水分指数在监测不同覆盖条件下的作物含水量具有一定的可行性,可丰富当前作物冠层含水量遥感监测的理论方法。展开更多
基金Supported by the Special Funds for the Major State Basic Research Project (973) (Grant No. G2000077900)the High-Tech Research and Development Program of China (Grant No. 2001AA135110)EAGLE (Exploitation of AnGular Effects in Land Surface Observation From Satellites in the Sixth Framework Program (FP6) of EU) (Grant No. SST3CT2003502057)
文摘In this paper, a new method for canopy water content (FMC) estimation for highly vegetated surfaces- shortwave infrared perpendicular water stress index (SPSI) is developed using NIR, SWIR wavelengths of Enhanced Thematic Mapper Plus (ETM+) on the basis of spectral features and distribution of surface targets with different water conditions in NIR-SWIR spectral space. The developed method is further explored with radiative transfer simulations using PROSPECT, Lillesaeter, SailH and 6S. It is evident from the results of validation derived from satellite synchronous field measurements that SPSI is highly correlated with FMC, coefficient of determination (R squared) and root mean square error are 0.79 and 26.41%. The paper concludes that SPSI has a potential in vegetation water content estimation in terms of FMC.
文摘为提高返青期-拔节期-开花期-灌浆期不同覆盖条件下小麦冠层含水量的遥感反演精度,综合分析基于Nir-Red和Nir-Swir光谱特征空间开展作物含水量监测的优势与局限,利用垂直干旱指数(perpendicular drought index,PDI)和短波红外垂直失水指数(shortwave infrared perpendicular water stress index,SPSI)的比值形式,构建了一种基于近红外-红波段-短波红外(Nir-Red-Swir)三波段光谱特征空间的垂直植被水分指数(three-band perpendicular vegetation water index,TPVWI)。结果表明,在不同生育时期,TPVWI与小麦冠层含水量(vegetation water content,VWC)均具有显著相关关系(P<0.01),且对植被含水量的敏感性优于PDI、作物水分监测指数(plant water index,PWI)、SPSI和NDVI 4种植被指数,且在反映小区域内小麦冠层含水量的时空趋势上有较好的表征能力。对比地面实测数据,利用TPVWI建立的作物含水量估测模型的预测精度较高,r与RMSE分别为0.763和2.296%,说明利用综合Nir-Red-Swir三波段光谱空间特征的植被水分指数在监测不同覆盖条件下的作物含水量具有一定的可行性,可丰富当前作物冠层含水量遥感监测的理论方法。
