Models of Radiation Scattering by Crystalline Plates on the Basis of the Method of Integral Representations for Fields

摘要

In recent years, the use of the millimeter and optical wave ranges in atmospheric studies has attracted much interest. Numerous papers on the effective use of microwave radiation for cloud probing are cited, e.g., in the survey [1]. It was shown experimentally that polarization characteristics of scattering of microwave and optical radiation by crystalline particles in clouds substantially depend on the distribution of particles in size, shape, and spatial orientation. Therefore, it would be of interest to use measurements of the cross-polarization of scattered radiation to determine the crystal orientation in a cloud. It is known that ice crystals in clouds substantially change their orientation depending on the combination of applied gravitational, aerodynamic, and electric forces. In particular, such measurements can be used in the analysis of atmospheric electricity. However, the implementation of these measurements requires a detailed analysis of the influence of the crystal size, shape, and orientation on the value of the scattered signal in various polarizations. Scattering of microwave radiation by variously shaped ice crystals in clouds can be treated with reasonable accuracy as Rayleigh scattering by spheroids whose principal axis ratios correspond to the same characteristic in real crystals [2, 3]. Related empiric expressions for particle size ratios depending on the crystal type are used in this connection.