Travel time estimation methods for mode tomography

At long ranges, broadband receptions consist of early ray-like arrivals and a finale that is best described in terms of the low order modes. The energetic low mode signals are more strongly affected by internal wave scattering than the ray arrivals. By focusing on the low modes, this project seeks to develop a better understanding of internal wave effects. The first objective of this project is to derive range-dependent mode statistics from experimental data obtained during the SPICE04 and LOAPEX experiments. The second objective of this project is to develop new robust signal processing techniques to estimate the travel times of the modes based on the derived statistical channel model.