Effects of Antenna Radiation on Coherent Back-Scattering from the Ocean Surface

Authors: Jimmy O. Alatishe and Wasyl Wasylkiwskyj

Source: FERMAT, Volume 20, Article 1, Mar.-Apr., 2017


Abstract: The analytical model previously developed by the authors for backscattering from a random air-dielectric interface is used to investigate the effects of coherence in the backscattered field on the monostatic radar cross-section (RCS) of the sea. The sea-surface is represented by several empirical wave-number spectra for a fully developed sea, namely, the Pierson-Neumann Spectrum, Pierson-Moskowitz Spectrum, and the Elfouhaily Unified Spectrum. A Generalized Normalized Radar Cross-Section (GNRCS) is introduced as a metric of the combined effects of coherence and antenna radiation characteristics. By employing a small-slope approximation (SSA) of the sea surface, the relative powers of the signal returns are computed and compared to the signal-power returns based on data-derived normalized RCS X-band (NRCS) (σ0 ) values for the corresponding simulated sea state. The objective of this analysis is to assess the effects of spatial coherence on backscattering using a GNRCS through validation with σ0 obtained from measurements of sea backscatter.

Index Terms: Generalized Normalized Radar Cross Section (GNRCS), Antenna Reciprocity, Ocean Backscattering, Antenna Radiation Pattern.


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Effects of Antenna Radiation on Coherent Back-Scattering from the Ocean Surface