Time-frequency representations for wideband acoustic signals in shallow water
Date of Original Version
Wideband acoustic propagation in shallow water has a unique arrival structure due to modal group speed dispersion. It is possible to unravel the modal dispersion characteristics using a proper time-frequency (TF) analysis. During the Asian Seas International Acoustics Experiment (ASIAEX) - East China Sea (ECS) experiment, signals collected by the vertical arrays have been processed using several time-frequency analysis techniques. Based upon the dispersion characteristics of acoustic propagation, theoretical time-frequency structure is used to determine the change of group delay. We present an improved time-frequency representation to provide higher resolution for TF diagrams using ECS data. The dispersion characteristics of ECS data are observed from these TF diagrams, and are verified by a theoretical model. Using this technique, higher modes can be observed with good resolution; this aids in increasing the performance of the inversion technique for long range sediment tomography.
Oceans Conference Record (IEEE)
Chen, Chuen S., James H. Miller, G. F. Boudreaux-Bartels, Gopu R. Potty, and Colin J. Lazauski. "Time-frequency representations for wideband acoustic signals in shallow water." Oceans Conference Record (IEEE) 5, (2003). https://digitalcommons.uri.edu/ele_facpubs/119