International Journal of Scientific Research and Engineering Development-– Volume 3 Issue 3, May – June 2020 Available at www.ijsred.com ISSN : 2581-7175 ©IJSRED: All Rights are Reserved Page 823 Attenuation of Millimeter Wave Propagation by Flat Sea-Surface Covered by Foam using Split- Step Fourier Transform Ayibapreye Kelvin BENJAMIN*, Collins E. OUSERIGHA** *Department of Electrical/Electronic Engineering, Niger Delta University, P.M.B 071 Yenagoa, Bayelsa State Nigeria Email:ayibapreyebenjamin@ndu.edu.ng ** Department of Physics, Niger Delta University, P.M.B 071 Yenagoa, Bayelsa State, Nigeria Email:ouserigha.ec@ndu.edu.ng ----------------------------------------************************---------------------------------- Abstract: In this article, we explore millimeter wave attenuation for discrete random scatterers, with emphasis on the application of microwave remote sensing in sea-foam covered sea surface. Polarimetric microwave emission from a sea-surface covered by foam were investigated. The foam is modelled as densely packed air bubbles coated with thin layer of seawater. Attenuation due to millimeter wave (mmW) propagation through layered sections of sea-foams were computed from split-step Fourier solutions of the parabolic equation method (PEM) derived from Helmholtz equation. The PEM is used to describe wave propagation through the layered medium. Results of attenuation by foam covered sea surface as a function of foam layer thickness and frequency for different polarizations are presented. Keywords —Attenuation, Foam, Flat sea-surface, Split-step Fourier Transform. ----------------------------------------************************---------------------------------- I. INTRODUCTION Earlier models used empirical microwave emissivity [1-4] to estimate the effect of foam presence at the crest of the ocean surface. This was achieved by passive microwave remote sensing measurements. These measurements were done by assuming physical micro-structure of foam and foam layer thickness. Measurement procedures were empirical fitting and based on experimental data. Foam dynamics has gained prominence in recent times. Pandey et.al, [5] proposed a composite model of foam scatterers and two scaled driven rough sea surfaces. In [6], controlled field experiments were used to measure foam dynamics and the microwave emissivity of calm water. A fully polarimetric passive model of wind generated and foam-covered rough sea can be represented by empirical Durden-Versecky spectrum [7]. Ding et al, [8] used a face centered cubic (FCC) structure to model high density spheres which represent bubbles placed inside a cube. Ding et al, [8] reported that polarization and frequency of the brightness temperatures are influenced by the physical micro- structural properties of foam and foam layer thickness. In spite of the fact that foam typically covers only a few percent of sea surfaces, sea surface emissivity can substantially increase with increase in foam coverage area [1,3,6]. However, there is a great concern on the impact of foam on retrieval of the ocean surface wind vector from satellite-mounted microwave instruments, which is due in large part RESEARCH ARTICLE OPEN ACCESS