目前光谱指数方法已被广泛地应用于植被叶绿素含量的反演中,考虑到不同传感器的光谱响应存在差异,研究了光谱尺度效应对光谱指数反演植被叶片叶绿素含量的影响。基于PROSPECT模型模拟了不同叶绿素含量(5~80μg·cm^(-2))下的5nm叶...目前光谱指数方法已被广泛地应用于植被叶绿素含量的反演中,考虑到不同传感器的光谱响应存在差异,研究了光谱尺度效应对光谱指数反演植被叶片叶绿素含量的影响。基于PROSPECT模型模拟了不同叶绿素含量(5~80μg·cm^(-2))下的5nm叶片光谱反射率数据,并利用高斯光谱响应函数将其分别模拟成10~35nm六种波段宽的光谱数据,再分析评价5~35nm波段宽下光谱指数与叶片叶绿素含量的相关性、对叶片叶绿素含量变化及对波段宽变化的敏感性。最后,利用波段宽为40~65nm的反射率数据对光谱指数反演植被叶绿素含量的光谱尺度效应进行验证。结果表明,通用光谱指数(vegetation index based on universal pattern decomposition method,VIUPD)反演叶绿素含量的精度最高,反演值与真实值拟合程度最好;归一化差值植被指数(normalized difference vegetation index,NDVI)和简单比值指数(simple ratio index,SRI)其次,虽然其决定系数R^2高达0.89以上,但反演的叶绿素含量值小于真实值;其他光谱指数的反演结果较差。VIUPD对叶绿素含量具有较好的相关性和敏感性,受光谱尺度效应影响较小,具有较好的反演能力,这一结论恰好验证了其"独立于传感器"的特性,同时证明了VIUPD在多源遥感数据反演植被理化参量的研究中具有更好的应用前景。展开更多
Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution...Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution which is inflation for < > end, and develops smoothly towards radiation-like evolution for ≥ end. The inflation is driven by the evolution of the field with inflation potential, V( ) = λ 2 v2)2.density, ns, is computed and ns lies well inside the limits set by the cosmic background explorer (COBE) satellite.the dex of the scalar effective cosmological constant Aeff tends to zero when inflation ends.展开更多
文摘目前光谱指数方法已被广泛地应用于植被叶绿素含量的反演中,考虑到不同传感器的光谱响应存在差异,研究了光谱尺度效应对光谱指数反演植被叶片叶绿素含量的影响。基于PROSPECT模型模拟了不同叶绿素含量(5~80μg·cm^(-2))下的5nm叶片光谱反射率数据,并利用高斯光谱响应函数将其分别模拟成10~35nm六种波段宽的光谱数据,再分析评价5~35nm波段宽下光谱指数与叶片叶绿素含量的相关性、对叶片叶绿素含量变化及对波段宽变化的敏感性。最后,利用波段宽为40~65nm的反射率数据对光谱指数反演植被叶绿素含量的光谱尺度效应进行验证。结果表明,通用光谱指数(vegetation index based on universal pattern decomposition method,VIUPD)反演叶绿素含量的精度最高,反演值与真实值拟合程度最好;归一化差值植被指数(normalized difference vegetation index,NDVI)和简单比值指数(simple ratio index,SRI)其次,虽然其决定系数R^2高达0.89以上,但反演的叶绿素含量值小于真实值;其他光谱指数的反演结果较差。VIUPD对叶绿素含量具有较好的相关性和敏感性,受光谱尺度效应影响较小,具有较好的反演能力,这一结论恰好验证了其"独立于传感器"的特性,同时证明了VIUPD在多源遥感数据反演植被理化参量的研究中具有更好的应用前景。
文摘Taking the Hubble parameter directly as a function of the scalar field instead of as a function of time,H = H( ), we present a new exact solution in the new inflation model with induced gravity. This includes solution which is inflation for < > end, and develops smoothly towards radiation-like evolution for ≥ end. The inflation is driven by the evolution of the field with inflation potential, V( ) = λ 2 v2)2.density, ns, is computed and ns lies well inside the limits set by the cosmic background explorer (COBE) satellite.the dex of the scalar effective cosmological constant Aeff tends to zero when inflation ends.
