Evaluation of Phase Perturbations induced by the Presence of Sea-foam on the Surface of the Ocean using Padé Approximation

Abstract

This paper reports phase perturbations induced by the presence of sea-foam on the surface of the ocean, when an incident electromagnetic wave (EM) at WindSat frequencies 10.7 GHz and 37 GHz was propagated through a foam-covered sea-foam layer modelled as sequences of phase scattering screens. The propagation process was modelled by Parabolic-Wave Equation (PWE) and solved by Padé approximation. The parabolic equation has been widely used to solving EM scattering and radio wave propagation problems. The split-step Pade’s approximation method is used in computation of the phase perturbations that occurs within the sea-foam layer due to the presence of varying effective dielectric constant of closely packed air-bubbles in the sea-surface. Results obtained show variation of the propagated E-fields through slices of sea-foam layer as functions of foam frequency, foam layer thickness, polarization and angle of incidence.

Keywords: Phase perturbation, sea foam, Padé approximation