FY 1994

Estimation of seafloor microtopographic roughness through modeling of acoustic backscatter data recorded by multibeam sonar systems

Matsumoto, H., R.P. Dziak, and C.G. Fox

J. Acoust. Soc. Am., 94(5), doi: 10.1121/1.407361, 2776–2787 (1993)

A method is described for estimating parameters related to the power-law frequency spectrum of seafloor interface roughness from acoustic backscatter strength measured from hull- mounted multibeam sonar arrays. Scattering parameters for a sediment-free seafloor are inversely derived from backscatter data using a Kirchhoff-based interface scattering model developed by Jackson et al. [J. Acoust. Soc. Am. 79, 1410-1422 (1986)]. A variety of data reduction routines are employed, including slope correction, beam-pattern and pulse-width corrections [de Moustier et al., J. Acoust. Soc. Am. 90, 522-531 (1991)], ping cross correlation, and an indirect method to account for the lack of system calibration. The method is applied to well-studied areas of the Juan de Fuca Ridge and the results compared to geological ground truth. Preliminary results indicate that the method may be valuable as a survey tool for routine mapping of seafloor acoustic properties.