This paper presents the filter correlation method, a technique for extracting consistent and accurate estimates of attenuation parameters from acoustic waveform data. The method minimizes problems associated with short time windows and multipath secondary arrivals. The method comprises two stages: a causal passband filter stage followed by a cross-correlation step. The results of the filter-correlation estimator are compared to those of the spectral difference approach for short time series with and without a secondary multipath arrival. Preliminary analyses of acoustic data collected on cored marine silts and clays show the attenuation properties of these materials cannot be described by a constant Q mechanism. The filter correlation method refines estimates of frequency-dependent velocity, revealing a small but systematic anisotropy between measurements made parallel and transverse to the sediments' bedding plane. The observed velocity anisotropy can be modeled by assuming layered porosity variations in the cored sediments. No systematic anisotropy in attenuation was observed.
Journal of the Acoustical Society of America
Acoustical Society of America
Digital Object Identifier (DOI)
The following article appeared in: R. C. Courtney and L. A. Mayer, ‘Calculation of acoustic parameters by a filter-correlation method’, The Journal of the Acoustical Society of America, vol. 93, no. 2, p. 1145, 1993. and may be found at http://dx.doi.org/10.1121/1.405509.
© 1993 Acoustical Society of America.This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.