Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment

Xiaoqin Zang, Michael G Brown, Neil J. Williams

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

It has been established theoretically and confirmed experimentally that two-point crosscorrelation functions (CFs) of diffuse acoustic noise result in approximations to Green's functions (GFs), which describe deterministic sound propagation between the two measurement points. In this paper we present approximations to GFs in the 20-70 Hz band that were obtained by cross-correlating concurrent records of ambient noise measured on near-bottom instruments at 5 and 10 km range in a 100 m deep coastal ocean environment in the Florida Straits. Interpretation of the measured CFs is challenging inasmuch as neither ray nor modal arrivals are temporally resolved. We employ a modal expansion of the wavefield to perform forward modeling of the CFs. This process requires that differences between CFs and GFs be accounted for. Using several different parameterizations of the seafloor structure, the inverse problem is investigated by performing an exhaustive search over the relevant parameter space to find the set of parameters that minimizes the integrated squared difference between simulated and measured CFs. Results show that simulated CFs yield 96.33% and 70.64% correlation coefficients with measured CFs at 5 and 10 km respectively. Moreover, a best-fitting geoacoustic model is obtained as a secondary result.

Original languageEnglish (US)
Title of host publication22nd International Congress on Sound and Vibration, ICSV 2015
PublisherInternational Institute of Acoustics and Vibrations
ISBN (Electronic)9788888942483
StatePublished - 2015
Event22nd International Congress on Sound and Vibration, ICSV 2015 - Florence, Italy
Duration: Jul 12 2015Jul 16 2015

Other

Other22nd International Congress on Sound and Vibration, ICSV 2015
CountryItaly
CityFlorence
Period7/12/157/16/15

Fingerprint

cross correlation
oceans
waveforms
inversions
Green's functions
straits
sound propagation
approximation
parameterization
correlation coefficients
arrivals
rays
expansion
acoustics

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

Cite this

Zang, X., Brown, M. G., & Williams, N. J. (2015). Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment. In 22nd International Congress on Sound and Vibration, ICSV 2015 International Institute of Acoustics and Vibrations.

Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment. / Zang, Xiaoqin; Brown, Michael G; Williams, Neil J.

22nd International Congress on Sound and Vibration, ICSV 2015. International Institute of Acoustics and Vibrations, 2015.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Zang, X, Brown, MG & Williams, NJ 2015, Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment. in 22nd International Congress on Sound and Vibration, ICSV 2015. International Institute of Acoustics and Vibrations, 22nd International Congress on Sound and Vibration, ICSV 2015, Florence, Italy, 7/12/15.
Zang X, Brown MG, Williams NJ. Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment. In 22nd International Congress on Sound and Vibration, ICSV 2015. International Institute of Acoustics and Vibrations. 2015
Zang, Xiaoqin ; Brown, Michael G ; Williams, Neil J. / Waveform modeling and inversion of ambient noise cross-correlation functions in a coastal ocean environment. 22nd International Congress on Sound and Vibration, ICSV 2015. International Institute of Acoustics and Vibrations, 2015.
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