Numerical study on the phase and amplitude statistics of backscattered signals from time-evolving sea surfaces

Abstract

A statistical analysis based on modulated compound Gaussian (CG) fields is performed on the phase and amplitude of backscattered signals, numerically generated using the method of ordered multiple interactions (MOMIs) for time-evolving one-dimensional (1D) Creamer surfaces. According to CG fields, theoretical models are revisited to investigate the statistics of phase difference and amplitude ratio as a function of time lag to reveal the modulation mechanisms of the backscattered signals. Numerical results demonstrate good agreements between the numerically generated statistics and the theoretical counterparts, providing with clear evidence that the numerically generated backscattered fields are jointly Gaussian distributed on short time-scales but, are modulated in amplitude by the long surface waves, which make the clutter returns departing from joint Gaussian model gradually. Such modulation mechanisms are coincident with the findings from the analysis of radar measurements published in references, further validating the applicability of the MOMI-based electromagnetic modelling process for sea clutter.