Wedge assemblage modeling of SAX99 backscatter strengths

Abstract

In SAX99 (Sediment Acoustics Experiment 1999), a number of high quality acoustic and environmental measurements were made in support of an ONR Department Research Initiative on high–frequency sound interaction in ocean sediments [M. D. Richardson et al. and E. I. Thorsos et al., IEEE J. Ocean Eng. 26, 4–53 (2001)]. Supporting environmental measurements include digital stereo photography of the interface roughness which were converted [A. P. Lyons et al., IEEE J. Ocean Eng. 27, 515–524 (2002)] to digital elevation maps. Using these micro-bathymetry data sets, the measured backscatter strengths from SAX99 are modeled via an extension of the wedge assemblage model [R. S. Keiffer and J. C. Novarini, J. Acoust. Soc. Am. 107, 27–39 (2000)] that allows for density-contrast between the water and sediment but assumes no change in the sound speed. In particular, SAX99 data in which changes in the acoustic backscatter can be directly related to the time evolution of the fine-scale interface morphology will be modeled and compared. [Work supported by ONR, Program Element No. 61153N-32 and by the DoD High Performance Computing Shared Resource Center (Stennis). This document has been reviewed and approved for public release.]