ABSTRACTS

Oral Session 7 | Wednesday, October 5, 11:20–11:40 | Abstract 486

Depolarization by randomly oriented irregular shaped amorphous particles

Estimating the source and amount of underwater depolarization by scattering particulates is becoming more important as various instruments with polarization measurement capabilities are being fielded. The most important source of depolarization for instruments measuring scattering in the near-forward direction is due particles containing birefringent materials such as calcite. There is however a smaller shape induced depolarization in particles made of amorphous materials which is notoriously difficult to estimate. We have developed a simple model that computes the depolarization induced by ensembles of randomly oriented irregular shaped particles. The model estimates the polarized phase function by treating the effect of the particles as identical to the transmission through two surfaces with randomly angularly distributed flat elements. The polarized phase function of the first surface is convolved with the identical phase function for the second surface to obtain the overall polarized phase function of the particle. Formulas are given for both the scattering coefficient and polarized phase functions. The amount of depolarization is compared with that induced by birefringent calcite particles of the same shape.

Georges Fournier, DRDC Valcartier Research Center

Griet Neukermans, Ghent University

Qiming Sun, Ghent University