Research Article
Computation of the Scattering Parameters Using Indian Lognormal Drop Size Distribution at 16, 19.3 and 34.8 GHz for Spherical and Oblate Spheroidal Rain Models

Aderemi Sikiru Adekola

Asian Journal of Scientific Research, 2008, 1(3), 213-221.

Abstract

Calculations of Millimeter-wave rain scattering parameters are made at 16, 19.3 and 34.8 using spherical and oblate spheroidal rain models. Computations are made at angle of incidence of 0 and 90 ° for the oblate spheroidal rain model. The characteristic of the difference between the two models with rain rate are studied at incidence angle of 0 ° to allow us determine their suitability in a tropical environment. Some propagation parameters are evaluated using the Indian lognormal and Marshall and Palmer (MP) Drop Size Distributions (DSD’s). Marshall and Palmer DSD model could underestimate rain-induced attenuation at all the frequencies in the rain rate range of 0.25≤R<50 mm h^-1 and overestimate specific phase shift at rain rate R>100 mm h^-1 if adopted for radio wave propagation prediction on tropical path. However, Indian data compare well with MP at rain rate in the range 50≤R≤100 mm h^-1. Similarly, spherical rain model could underestimate the specific attenuation with a maximum margin of 3.4 dB km^-1 at 34.8 GHz and specific phase shift of 15.7 ° km^-1 at 16 GHz, both at rain rate of 150 mm h^-1. The empirical scaling relationship between the radar reflectivity η and rain rate R (η = aR^b) are derived for the Indian DSD and the coefficients a and b compare well with those of Aydin and Lure.

ASCI-ID: 8-32

Cited References Fulltext

Cited By

Indian Journal of Physics, 2012, 86(8), 709. DOI: 10.1007/s12648-012-0066-6

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