Phase Integral Algorithms for Signal Speeds in Range-Dependent Sound Velocity Profiles

摘要

This report presents two Fortran raytracing codes and related theory which are designed to treat underwater sound propagation in the presence of range-dependent sound velocity profiles (SVPs). Particular emphasis is placed on the average horizontal ray velocity and its variation as a ray traverses different SVPs. Efficient calculation of this variation is of great importance for improved modern multisensor localization techniques. The adiabatic invariant approximation agrees well with exact raytracing results even for strongly inhomogeneous sound velocity profiles. Simple algorithms are developed for demonstrating this and for computing the adiabatic invariant in arbitrary profiles for a user-selected family of rays.