High-frequency source localization in the Strait of Sicily

One of the keys for a successful inversion of acoustic data using the matched-field processing (MFP) technique is the amount of environmental and geometric information available. When this information is missing or erroneous then one is in the presence of model mismatch. To work at higher frequencies provides better discrimination in range and depth but also increases the dependency of the inversion algorithm on mismatch which, in practice, leads to a tradeoff between discrimination and mismatch. The ADVENT'99 sea trial took place in the area of the Adventure Bank in the Strait of Sicily during May 1999, with the objective of testing MFP techniques. A 62-m aperture vertical line array was deployed at 2, 5 and 10 km from an acoustic source. The source was emitting a series of multi-tone signals in the band of 800-1600 Hz. This paper tests a two step MFP algorithm in the higher frequency band for the 2 and 5 km tracks: in the first step the data is pre-focused using genetic search where the environmental and geometric parameters are estimated and in the second step an exhaustive search is performed for source range and depth.