Acoustic bottom reflectivity

Abstract

Acoustic reflectivity from the seafloor is often an important factor influencing the performance of ASW systems in different environments, such as in deep water when the bottom bounce paths are used, and in general in influencing sound propagation in shallow water. This report summarizes the work that has been pursued in this field for more than 20 years.

The following topics are discussed: general equations; reflection coefficient and impedance; the half-space bottom; attenuation; general layering; solid half-space; liquid layers; high loss at grazing; density gradient; examples of general layering; impulse response; periodic layers; measurement of bottom reflectivity; data analysis methods; and prediction of bottom reflectivity. It is stressed that only the plane wave reflection coefficient is considered.