Modeling range dependent sediment and interface roughness effects on propagation loss with finite elements

At the Target and Reverberation Experiment (TREX) off the coast of the Florida panhandle in May 2013, propagation loss was measured over a track with significant sediment and interface roughness variability. In this study, the finite element method is applied to model the effects of sediment and interface roughness variability on transmission loss. Finite elements provide a full wave solution to the Helmholtz equation to the accuracy of the discretization. Therefore, it provides both forward and backward propagation fields. Where available, data will be taken from TREX environment measurements. Additionally, the results will be compared with an energy loss model which relies on the product of the range dependent reflection coefficient. [Work supported by ONR, Ocean Acoustics.]