Sonar propagation modeling using hybrid Gaussian beams in spherical/time coordinates

Abstract

This paper defines a new undersea acoustic transmission loss model that is optimized for real-time, sonar simulation/stimulation systems in littoral environments. The ray solutions to the eikonal equation are computed in latitude, longitude, and altitude coordinates to match wide-area environmental databases. Hybrid Gaussian beam techniques for transmission loss calculation are used to extend the applicability of ray theory to lower frequency regimes. Numerical integration of the wave equation is performed in the time dimension to support broadband signal modeling. This 3-D approach also supports out-of-plane reflection from the ocean bottom. This paper derives the eikonal solution from first principles to ensure a complete understanding of the coordinate system's impact.