We analyze the possibilities of orbital photopolarimetric measurements to study properties of aerosols in the Earth's atmosphere. As an example, we consider the case when such measurements are performed within a narrow spectral channel centered at 1.378 µm that allows to retrieve microphysical characteristics of stratospheric aerosols separately from those of tropospheric aerosols. We consider the case of stratospheric aerosols caused by volcanic eruption, and adopt the model of the stratosphere in the form of a homogeneous plane-parallel layer composed of polydisperse spherical particles. We use numerically exact solutions of the vector radiative transfer equation to theoretically simulate measurements carried out at various numbers of scattering angles, including: (i) radiance measurements alone; (ii) polarization measurements alone; and (iii) radiance and polarization measurements together. The results of computations show that the simultaneous use of radiance and polarization measurements at a sufficiently large number of scattering angles enables one to retrieve the optical thickness, effective radius, and refractive index of aerosols with adequate accuracy. We demonstrate how the accuracy of the derived values of the optical parameters of aerosols depends on the accuracy of measurements of the intensity and polarization of the reflected light, optical thickness of aerosol layer itself, effective radius of aerosols, width of the particle size distribution, and number of viewing angles.

我们分析了轨道光极化测量的可能性，以研究地球大气中气溶胶的特性。例如，我们考虑在以1.378 µm为中心的狭窄光谱通道内进行此类测量的情况，该通道可分别获取平流层气溶胶的微物理特征与对流层气溶胶的微物理特征。我们考虑了由火山喷发引起的平流层气溶胶的情况，并采用由多分散球形颗粒组成的均质的平面平行层形式的平流层模型。我们使用矢量辐射传递方程的精确数值解来理论上模拟在各种散射角下进行的测量，包括：（i）单独的辐射测量；（ii）仅偏振测量；（iii）辐射度和极化度的测量。计算结果表明，在足够多的散射角下同时使用辐射度和偏振度测量值，可以使人们以足够的精度检索气溶胶的光学厚度，有效半径和折射率。我们演示了气溶胶光学参数的推导值的准确性如何取决于反射光的强度和偏振，气溶胶层本身的光学厚度，气溶胶有效半径，粒径分布宽度的测量精度，和视角数。计算结果表明，在足够多的散射角下同时使用辐射度和偏振度测量值，可以使人们以足够的精度检索气溶胶的光学厚度，有效半径和折射率。我们演示了气溶胶光学参数的推导值的准确性如何取决于反射光的强度和偏振，气溶胶层本身的光学厚度，气溶胶有效半径，粒径分布宽度的测量精度，和视角数。计算结果表明，在足够多的散射角下同时使用辐射度和偏振度测量值，可以使人们以足够的精度检索气溶胶的光学厚度，有效半径和折射率。我们演示了气溶胶光学参数的推导值的准确性如何取决于反射光的强度和偏振，气溶胶层本身的光学厚度，气溶胶有效半径，粒径分布宽度的测量精度，和视角数。