Non-Rayleigh scattering by a randomly oriented elongated scatterer
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KeywordMonte Carlo method
The echo statistics of a randomly rough, randomly oriented prolate spheroid that is randomly located in a beampattern are investigated from physics-based principles both analytically and by Monte Carlo methods. This is a direct-path geometry in which reflections from neighboring boundaries are not a factor. The center of the prolate spheroid is assumed to be con fined to the plane containing the MRA (maximum response axis). Additionally, the rotation of the prolate spheroid is assumed to always be in this plane. The statistics and, in particular, the tails of the probability density function (PDF) and probability of false alarm (PFA) are shown to be strongly non-Rayleigh and a strong function of shape of scatterer. The tails are shown to increase above that associated with a Rayleigh distribution with increasing degree of elongation (aspect ratio) of the scatterer and when roughness effects are introduced. And, as also shown in previous studies, the effects associated with the scatterer being randomly located in the beam contribute to the non-Rayleigh nature of the echo. The analytically obtained results are compared to Monte Carlo simulations for verification.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 2012
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