Bottom Grain Gas and Roughness Technique (BOGGART) Version 1.0: Bottom Backscatter Model User's Guide.

A use's guide for ARL:UT's marine sediment acoustic backscatter model has been developed. The model, named BOGGART (Bottom Grain Gas and Roughness Technique), is a three-component model which computes the total backscattering strength as an incoherent sum of contributions from three components. They are (1) scattering from sediment grains, (2) scattering from trapped gas bubbles within the sediment, and (3) scattering from interface roughness. The grain scattering is modeled empirically in lieu of a theoretical model which is under development. The gas bubble and roughness scattering components are theoretical. Acoustic propagation in the sediment is modeled by way of the Biot theory for poroelastic media. This report describes BOGGART's program structure, as well as its input and output file management. It is intended to suffice as a user's description of the model's operation.