Array positioning, bathymetry, and geoacoustic parameter estimation in a wedge-shaped ocean environment

In 1987 an underwater acoustic propagation experiment was carried out at a site with a nearly uniformly sloping seafloor off the west coast of Vancouver Island. SUS charges were used as sources and the receiver was the 2-km-long COAMS towed array. In an earlier paper the data collected were analyzed and compared with a-way PE model predictions. The comparison showed excellent agreement in terms of mean losses, but the locations of the maxima and minima of the transmission losses were not well predicted. The current work attempts to lay the necessary ground work to improve on the earlier analysis by resolving difficulties that occurred in several areas. The accuracy of the hydrophone positions has been improved using acoustic travel time measurements. Bathymetry estimates have been refined from echo-sounder data and minimization techniques have been investigated for their potential to improve the bathymetry estimates still further. Finally, geoacoustic parameters have been determined from reflection data. The resulting geoacoustic model and other refinements will eventually be used with the PE model to see if a more accurate prediction of transmission loss can be made.<
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