raytrace

A function to model acoustic refraction due to variations in sound speed.

In ocean acoustics a common task is to model the propagation of sound through the water column. The speed of sound varies with temperature, salinity and pressure (depth). To a first approximation, the ocean is horizontally stratified and these parameters only vary with depth. Variations in sound speed in layers of the water column cause a "ray" of acoustic energy to be refracted (to bend) as the ray passes through it.

When given a starting location, launch angle, vertical sound speed profile and total travel time, the attached function, raytrace.m, models the propagation of sound though a water column. It handles both reflection from the surface of the water and the bottom (the deepest depth given in the sound speed profile) as well as caustics (places in which the ray is bent back in the direction from which it came). Raytrace automatically plots the provided sound speed profile and the results of the ray-trace.

Although raytrace.m is designed for ocean acoustics, the mathematics for optical refraction is the same and where the assumptions apply raytrace.m will produce reasonable results.