Eigenray finding and time series simulation in a layered-bottom ocean

Abstract

A ray theory approach for simulating the propagation of broadband signals interacting with a layered ocean bottom is presented. The range-invariant environment consists of the ocean and an arbitrary number of bottom layers. Each bottom layer has profiles of compressional and shear wave velocity, attenuation, and density. Eigenrays, including those with multiple interactions and refractions in the ocean and bottom layering, are found using a thorough and efficient algorithm based on an analysis of the sound velocity profile and the dependence of ray path geometry on the Snell invariant. The time series at a receiver due to an arbitrary source waveform is obtained by constructing a frequency domain transfer function from the eigenray characteristics. Several example applications demonstrate the potential use of this approach and show that reflection from relatively simple layering can severely distort a received time series.