年間 12 号発行
ISSN 印刷: 0040-2508
ISSN オンライン: 1943-6009
Indexed in
RADAR CROSS SECTION OF NONSPHERICAL RAINDROPS
要約
Considerable attention is devoted to the radar methods of measuring characteristics of rains in connection with studies of physical processes in the atmosphere, as well as for solving practical problems. However, existing methods of calculating the reflection characteristics are based on the assumption of a spherical shape of rain particles, whereas, in most cases the shape of real raindrops has a nonspherical shape. Therefore, in this paper, the research results of backscattering are considered from ellipsoidal drops and the Pruppacher-Pitter drops that are most widely used at description of nonspherical particles. In the process as a method of calculation we use the dipole scattering approximation and rigorous method of moments. Comparative calculations were made for horizontal and vertical polarization of the incident field at wavelengths λ = 0.8, 3.2, 5.5 and 10 cm, which gave values of the calculation error of the effective radar cross section of drops using approximate methods. Also polynomial approximation of rigorous calculations results is proposed and the expansion coefficients are found, which allows to use the given data for calculation of the scattering characteristics in the case of polydispersed medium.