光谱学与光谱分析, 2014, 34 (3): 619, 网络出版: 2014-03-14
叶片多角度偏振光谱特性影响因素的实验研究
Study on Multi-Angular Polarized Spectrum Characteristics of Leaf Based on Some Indoor Experimental Data
植物叶片 偏振度 斯托克斯矢量 多角度 生理参数 Plant leaf Degree of polarization Stokes parameters Multi-angle Physiological parameters
摘要
通过测量绿萝、 银杏、 苹果三种叶片的多角度偏振光谱, 采用斯托克斯矢量法计算了叶片的多角度光谱偏振度, 并通过PROSPECT模型反演得到叶片的叶绿素、 水分含量, 进而分析了叶绿素、 水分含量对叶片多角度光谱偏振度的影响, 探索了观测几何条件与不同波段叶片偏振度间的关系。 结果表明, 相对于近红外波段, 红光波段的偏振度受叶绿素含量变化的影响较小, 而水分含量对这两个波段的偏振度基本均无明显影响。 在反映叶片偏振度随观测几何变化方面, 近红外波段较另外两个波段有着更好的敏感性和稳定性, 但其偏振度值较另外两个波段偏小。
Abstract
In the present study, we acquired multi-angular polarized spectrum of three kinds of leaves with different surface structures, and calculated the multi-angular spectral degree of polarization DOP based on Stokes parameters to explore its variation tendency with wavelength and the relationship between the leaf polarized reflectance and its physiological parameters and the relative observational geometric condition. The results show that although the spectral degree of polarization of the 3 kinds of leaves has obvious differences in value because of the leaf surface structures, the general trend of the DOP curve keeps consistent, and this trend could be explained by analyzing the properties of both specular and diffuse components of the leaf reflectance. The peak value of the DOP appears in the specular direction of the principal plane, and grows with the increase in the incident zenith angle. The analysis of the data demonstrates that compared to the other two experimental bands, the near infrared band shows a better discrimination in showing the relationship between DOP and the observational geometric configuration for all the three kinds of leaves, but the value of the DOP is smaller. Considering the effect of variation in chlorophyll content, DOP of the red band has more stable value than the near infrared band, whereas the water content has barely influence in both of the bands.
孟夏, 谢东辉, 汪艳, 贾颖芳, 阎广建. 叶片多角度偏振光谱特性影响因素的实验研究[J]. 光谱学与光谱分析, 2014, 34(3): 619. MENG Xia, XIE Dong-hui, WANG Yan, JIA Ying-fang, YAN Guang-jian. Study on Multi-Angular Polarized Spectrum Characteristics of Leaf Based on Some Indoor Experimental Data[J]. Spectroscopy and Spectral Analysis, 2014, 34(3): 619.