Forward and back scattering in a shallow inhomogeneous environment

An experiment in 20 m of water off Panama City, FL, motivates the simulation with several propagation models of the time series produced from rough seabed scattering. Both the forward and backward scattered time series are simulated on vertical line arrays in the 2–4 kHz band to ranges out to 5 km. Results from several Born approximation approaches are compared to the results of a full numerical two-way coupled-mode solution to analyze the measured data. The results from a method of separating the forward and backward scattered amplitudes are also presented. Competing effects, such as the interplay between modal attenuation and the scattering of the higher order modes, are examined within the context of both the full coupled-mode and Born approximation solutions.