A bistatic, high‐frequency, under‐ice, acoustic scattering model. I: Theory

Abstract

A model is described that has been developed to evaluate the scatter produced by a high‐frequency acoustic pulse that originates from a stationary and arbitrarily located source; is incident on and scattered from an under‐ice surface characteristic of pack ice regions of the interior Arctic; and is detected by a stationary and arbitrarily located receiver. Measured, two‐dimensional, under‐ice, acoustic profile data and several empirical results that relate various geometric parameters of large‐scale under‐ice relief features (e.g., ice keels) are used to construct a three‐dimensional, under‐ice surface model consisting of first‐year ice keels and sloping, flat ice regions. A first‐year ice keel is modeled as an ensemble of randomly oriented ice blocks on a planar surface inclined at some slope angle with respect to a horizontal plane at sea level. Ice blocks are modeled as layered, viscoelastic solids with smooth rectangular faces or facets. A region of flat ice is modeled as a smooth planar surface whose...