Focalization in environments with stochastic sediment uncertainties

Focalization has recently been generalized to problems involving internal waves [R. N. Baer and M. D. Collins, J. Acoust. Soc. Am. 115, 2550 (2004)]. Although there are basic differences between this stochastic focalization problem and the deterministic focalization problems that were considered previously, the essential concept of a parameter hierarchy applies to both problems. Stochastic focalization is currently being implemented and tested for problems involving uncertainties in the sediment. This source localization problem is of practical importance since there are often significant uncertainties in sediments. Like internal waves, ocean sediments can be highly complex. Although it is often desirable to invert for ocean bottom parameters, this is not always practical when source localization is the main goal. Due to the parameter hierarchy, it is often possible to determine the correct source position without determining the correct sediment parameters. [Work supported by the ONR.]