Many plant species have dorsiventral leaves that have significant differences in optical properties from one side to the other. Several studies have revealed that ignoring this asymmetry induces significant errors in plant canopy reflectance, and current leaf models simulating leaf dorsiventrality are limited to the 0.4–2.5 m wavelength range. This article, partly based on two recently collected datasets in the 2.5–14 m wavelength range, demonstrates that ignoring leaf dorsiventrality induces significant errors in brightness temperature and effective emissivity at the canopy scale. The PROLIB model, which inherits from the PROSPECT-VISIR and LIBERTY models, is the first radiative transfer model to simulate the reflectance and transmittance of both leaf sides from 0.4 to 5.7 m. The palisade and spongy mesophylls are represented as plate and sphere layers, respectively, to account for the structural asymmetry of leaf cells. The sieve effect that explains the differences in transmittance between the adaxial and abaxial sides of the leaf is successfully incorporated into PROLIB. Evaluation of the model on several leaf datasets shows that: (1) It reproduces well the adaxial and abaxial optical properties of the leaves, with a root mean square error (RMSE) of 0.0109 for reflectance and transmittance. (2) It can be inversed to retrieve leaf traits, with RMSE values for leaf chlorophyll, carotenoid, anthocyanin, water, and dry matter content of 5.519 g/cm, 2.344 g/cm, 4.219 g/cm, 0.0022 g/cm, and 0.0017 g/cm, respectively (corresponding normalized RMSE values of 22.0%, 34.0%, 49.4%, 19.6%, and 24.7%). However, better and more complete leaf datasets are needed for leaf dorsiventrality analysis and model calibration.

中文翻译：

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PROLIB 叶片辐射传输模型：从可见光到中波红外模拟叶片背心

许多植物物种都具有背腹叶，其一侧与另一侧的光学特性存在显着差异。多项研究表明，忽略这种不对称性会导致植物冠层反射率出现显着误差，并且当前模拟叶片背心的叶片模型仅限于 0.4–2.5 m 波长范围。本文部分基于最近收集的 2.5-14 m 波长范围内的两个数据集，证明忽略叶片背心会导致冠层尺度的亮度温度和有效发射率出现显着误差。 PROLIB模型继承了PROSPECT-VISIR和LIBERTY模型，是第一个模拟0.4至5.7 m范围内叶面反射率和透射率的辐射传输模型。栅栏和海绵叶肉分别表示为板层和球层，以解释叶细胞的结构不对称性。筛子效应可以解释叶片近轴侧和远轴侧之间透射率的差异，该效应已成功融入 PROLIB 中。该模型在多个叶片数据集上的评估表明：（1）它很好地再现了叶片的近轴和远轴光学特性，反射率和透射率的均方根误差（RMSE）为0.0109。 (2)可反演叶片性状，叶片叶绿素、类胡萝卜素、花青素、水分、干物质含量的RMSE值为5.519 g/cm、2.344 g/cm、4.219 g/cm、0.0022 g/cm，和 0.0017 g/cm（相应的标准化 RMSE 值为 22.0%、34.0%、49.4%、19.6% 和 24.7%）。然而，叶片背心分析和模型校准需要更好、更完整的叶片数据集。