Title: A new ray-tracing algorithm for arbitrary inhomogeneous and moving media, including caustics
Abstract: In this paper, a new ray-tracing algorithm is presented that can handle arbitrary temperature and wind profiles in horizontal and vertical directions. This is accomplished by following a ray tube instead of a ray path. The algorithm is a direct finite difference implementation of the ray-tracing equations for arbitrary temperature and wind profiles. A computer model has been made, based on this algorithm. Special attention is given to the shortcomings of ray theory in the case of caustics, which are compensated for by appropriate phase and amplitude corrections of the computed ray tubes. The method is well suited to study the effect of locally heated areas on the sound propagation, as occurring on for instance petrochemical plants. Numerical experiments show that the proposed ray-tracing method and the relatively expensive, but accurate, wave field extrapolation method agree very well in many cases.