Acoustic pulse propagation studies in the Gulf of Mexico

To investigate the feasibility of monitoring the movements of the large eddies that dominate circulation in the deep waters of the Gulf, normal-mode acoustic propagation studies are made using historic data for sound-speed profiles representing the distinction among the various water masses inside and outside these eddies. Two working frequency bands of a pulse source (400-600 Hz, 900-1100 Hz) and deep-water source placements (900m) are used in modeling. The temporal structure of the arrived signals has shown the possibility of distinguishing among those water types. Details of the arrival patterns show significant variations for the different waters on scales of 0.02 to 0.1 seconds. A range of transmission losses in the deep-water channel is typically -90 to -120 dB over the 388-km propagation path used in the modeling, which gives an estimate of the requirements for the source-receiving system.