Exploration of Lloyd mirror rotation effect and radar look down angle

Abstract

A model designed to propagate electromagnetic fields in complicated terrestrial environments was used to make forward scatter predictions. The propagation model is capable of generating various rough sea surfaces with Donelan-Pierson-Banner wind-wave spectra. The rough sea surface feature of the propagation model was parameterized to simulate the surfaces generated during a forward scatter measurement. The Lloyd mirror rotation effect was observed during the measurement and in the predictions; this phenomenon is explored below. The Lloyd mirror rotation effect in a rough sea environment is explored by increasing the radar look down angle and observing its effect on the forward scatter interference pattern. Comparisons between forward scatter data and predictions from a parabolic wave equation (PWE) model are included. The measurement was performed in the Maneuvering and Sea-Keeping (MASK) basin at the Naval Surface Warfare Center in West Bethesda, MD. The variable terrain radio wave parabolic equation (VTRPE) is a range-dependent propagation model that solves the full wave equations for the complex radiation fields. The VTRPE code was used to simulate the sea surfaces generated during the measurement and make predictions of the forward scatter interference pattern.