PlaneRay: An underwater acoustic propagation model using ray tracing and plane wave reflection coefficients

Abstract

Recently there has been a renewed interest in using ray tracing techniques for propagation modeling in underwater acoustics and this paper describes a newly developed model. A special and essential feature of this model is a unique sorting and interpolation routine for efficient determination of a large number of eigenrays and also for range‐dependent environments. No rays are traced into the bottom and the bottom interaction is modeled by plane wave reflection coefficients. In the current version of the model the bottom structure consists of a fluid sediment layer over a solid half‐space. Important considerations are the accuracy of the ray model and, in particular, how accurate the plane wave reflection coefficients can represent the effects of a layered bottom. This problem is analyzed by comparing the time and frequency domains solution of the ray model with models based on the wave number integration technique. There are two conflicting requirements since ray tracing is valid for high frequencies and the used plane wave reflection coefficient is valid for low frequencies where the sediment layers are thin compared with the acoustic wavelength. A number of illustrative examples are presented.