Broadband Waveform Geoacoustic Inversions With Absolute Travel Time

Numerical and experimental studies were conducted to investigate the advantage of utilizing absolute travel time information in Bayesian geoacoustic inversions of broadband acoustic data. It is shown that inversions using absolute travel time can yield smaller uncertainties compared to inversions using relative arrival time and maximum-likelihood estimates for clock time synchronization. Experimental data collected in the Seabed Characterization Experiment on the New England Mud Patch in the Middle Atlantic Bight were used for real data demonstration, and it is shown that inversions using relative arrival times have greater uncertainty in estimating source distance, which consequently affects the overall posterior probability distribution of inverted parameters. Numerical study enables investigation of performance dependence on the signal-to-noise ratio, and it is found that absolute travel time information may have more profound advantages when the signal-to-noise ratio is low.