Coulson K L
Department of Agricultural Engineering,University of California, Davis, California, USA.
Appl Opt. 1966 Jun 1;5(6):905-17. doi: 10.1364/AO.5.000905.
Measurements of the reflecting and polarizing properties of various soils, sands, and vegetation in the visible-and near-ir spectral regions show that dark surfaces polarize the reflected radiation strongly while highly reflecting surfaces have relatively weak polarizing properties. In general, the reflectance of mineral surfaces increases, and the degree of polarization of the reflected radiation decreases, with increasing wavelength and increasing angle of incidence. There is little or no indication of specular reflection from the surfaces for which measurements were made. Introduction of the reflection data into the equation of radiative transfer for clear and slightly turbid models of the earth's atmosphere shows that the upward radiation that would be incident on a high-altitude aircraft or satellite would be dominated by surface-reflected radiation for the red and near-ir regions over highly reflecting surfaces such as deserts, whereas atmospheric scattering is most important for short wavelengths and dark surfaces. Because of polarization effects, atmospheric transmission of optical contrasts is better in one orthogonal intensity component than the other, the difference being sufficient to merit polarizing optics in reconnaissance instrumentation under certain conditions.
对各种土壤、沙子和植被在可见光及近红外光谱区域的反射和偏振特性进行测量表明，深色表面会强烈偏振反射辐射，而高反射表面的偏振特性相对较弱。一般来说，矿物表面的反射率会随着波长增加和入射角增大而增加，而反射辐射的偏振度会降低。在进行测量的表面上，几乎没有镜面反射的迹象。将反射数据代入地球大气清晰和轻度浑浊模型的辐射传输方程表明，对于高反射表面（如沙漠）上的红色和近红外区域，入射到高空飞机或卫星上的向上辐射将以表面反射辐射为主，而对于短波长和深色表面，大气散射最为重要。由于偏振效应，光学对比度在大气中的传输在一个正交强度分量中比另一个更好，这种差异足以在某些条件下使侦察仪器中采用偏振光学器件。
