Statistics of Simulated Ocean Clutter

Abstract

The statistical description of ocean clutter, which is made use of by the modern clutter suppression algorithms, is examined for sea states 0 and 4, for a grazing angle range 0.14° _gr 89.5° , for all polarizations, and for upwind and crosswind returns. The data for statistical description are obtained by a radar simulation program in which the electromagnetic pulses are traced in a user defined radar environment. In this simulation environment, the returns which are backscattered from the ocean surface are recorded individually along with their polarization, amplitude, phase, arrival time and Doppler shift. Based on the likelihood ratios of commonly used Rayleigh, Lognormal, Weibull and K-distribution families, the best fitting distributions to the observed data are chosen. When the results obtained are compared with those available in the literature, a good agreement is observed. Due to the limitations of experimental studies, the data necessary for the statistical description of the amplitude and the power of clutter are either not available or scarce for various sea states, grazing angles, polarizations and wind directions. For those cases where the statistical description is not available in the literature, the simulation program provides an inexpensive and reliable environment to obtain the best fitting distributions, which is an important ingredient of the modern clutter suppression algorithms.