Multiple scattering calculations of rain effects
Abstract
At millimeter wave frequencies the scattering cross section of raindrops becomes comparable to the absorption cross section, and incoherent intensity due to multiple scattering may become significant. This paper presents calculations of the incoherent intensity at 30, 60, 90, and 120 GHz. The scattering and absorption characteristics of the rain are calculated using the Mie solution and the LawsParsons distribution. Incoherent intensities for the horizontal and vertical polarizations are obtained using the equation of transfer and the Stokes parameters. The obliquely incident wave is linearly polarized. The equation of transfer is solved by using the Gauss quadrature formula and the matrix eigenvalue technique. The matrix elements are calculated using the formulations developed by Sekera, and the vertical and horizontal components and their correlations are used in the Stokes parameter representations. The received incoherent intensity depends on the field of view of the receiving antenna. The ratio of the copolarized incoherent intensity to the copolarized coherent intensity is defined as the incoherent copolarized discrimination ICPD, and the ratio of the crosspolarized incoherent intensity to the copolarized coherent intensity is defined as the incoherent crosspolarized discrimination IXPD. These are computed in terms of rain rate, field of view, and copolarized attenuation. It is shown that multiple scattering effects may become significant during heavy rains. Backscattering results are also presented.
 Publication:

Radio Science
 Pub Date:
 December 1982
 DOI:
 10.1029/RS017i006p01425
 Bibcode:
 1982RaSc...17.1425I
 Keywords:

 Atmospheric Scattering;
 Microwave Scattering;
 Mie Scattering;
 Polarization Characteristics;
 Radiative Transfer;
 Raindrops;
 Atmospheric Attenuation;
 Cross Polarization;
 Electromagnetic Absorption;
 Microwave Attenuation;
 Communications and Radar