Estimation of leaf transmittance in the near infrared region through reflectance measurements
Estimation of leaf transmittance in the near infrared region through reflectance measurements
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DOI：
10.1016/j.jphotobiol.2004.03.003
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发表时间：
2004-05-27
影响因子：
5.4
通讯作者：
Naqvi, KR
中科院分区：
文献类型：
--
作者：
Merzlyak, MN;Melo, TB;Naqvi, KR
最近发展了一种方法，该方法允许通过积分球补偿透射光（T）的不完全收集，并且证明只要叶片在近红外区域的吸收率（A）是可靠的，（750-800 nm）的反射率可以忽略，允许设置R + T = 1，其中R表示反射率;这意味着适当的补偿只能应用于在NIR区域不吸收的健康叶子。为了克服这一限制，一种替代方案的可行性，既不需要测量的T，也不需要通过一片叶子的辐射传输的详细分析，探索。毫不奇怪，这种简化的替代方案提供的结果（通常）与使用补偿方法发现的结果不一致，但这两种方法在吸收率低的光谱区域（即R + T大于或等于0.9）收敛。因此，如本文所述，“T-通过-R”方法提供了对结合积分球使用的校正因子的额外检查，并且将补偿方法的适用性扩展到NIR吸收率不可忽略的情况，例如，在叶衰老过程中多酚氧化产生的“布朗宁”色素的存在下。(C)2004 Elsevier B. V.保留所有权利。
A method, which allows one to compensate for the incomplete collection of transmitted light (T) by an integrating sphere, has recently been developed, and shown to be reliable provided that the absorptance (A) of the leaf in the NIR region (750-800 nm) can be neglected, allowing one to set R + T = 1, where R denotes the reflectance; this implies that proper compensation can only be applied to healthy leaves, which do not absorb in the NIR region. To overcome this limitation, the feasibility of an alternative, requiring neither measurements of T nor an elaborate analysis of radiative transport through a leaf, is explored. Not surprisingly, this simplistic alternative provides results which (in general) do not agree with those found by using the compensation method, but the two approaches converge in the spectral regions where absorptance is low (that is, where R + T greater than or equal to 0.9). The "T-through-R" method, as described here, thus provides an additional check on the correction factor used in conjunction with the integrating sphere, and extends the applicability of the compensation method to situations where NIR absorptance is not negligible, e.g., in the presence of 'browning' pigments produced upon the oxidation of polyphenols during leaf senescence. (C) 2004 Elsevier B.V. All rights reserved.