A simple method for kinematic ray tracing in 3-d heterogeneous media, continuos and discrete

Abstract

A simple method for kinematic ray tracing in 3-D heterogeneous media is presented. The method is based on the well known "circular approximation", which holds for 2-D heterogeneous media, and it can be used for both continuous and discrete 3-D media. 2-D media are a particular case (a profile), as well as discrete 3-D media, where the space units are irregular tetrahedrons, inside of which the velocity behaves linearly with the coordinates. The method requires analytical determination of the velocity and velocity gradients: it is fast and accurate, and requires minimum computer time and memory. Also, it is extremely versatile in that it allows easy handling of specific heterogeneities. Synthetic examples arc provided.