Arrival-time structure of the time-averaged ambient noise cross-correlation function in an oceanic waveguide

Abstract

Coherent deterministic arrival times can be extracted from the derivative of the time-averaged ambient noise cross-correlation function between two receivers. These coherent arrival times are related to those of the time-domain Green's function between these two receivers and have been observed experimentally in various environments and frequency range of interest (e.g., in ultrasonics, seismology, or underwater acoustics). This nonintuitive result can be demonstrated based on a simple time-domain image formulation of the noise cross-correlation function, for a uniform distribution of noise sources in a Pekeris waveguide. This image formulation determines the influence of the noise-source distribution (in range and depth) as well as the dependence on the receiver bandwidth for the arrival-time structure of the derivative of the cross-correlation function. These results are compared with previously derived formulations of the ambient noise cross-correlation function. Practical implications of these results for sea experiments are also discussed.

Estimation of the effect of nonisotropically distributed energy on the apparent arrival time in correlations

“…Afterwards, different theoretical approaches have formalised the link between correlation of random diffuse fields and Green's function retrieval Lobkis and Weaver, 2001;Derode et al, 2003a,b;van Tiggelen, 2003;Wapenaar, 2004;Snieder, 2004;Roux et al, 2005). The crosscorrelation technique has been used successfully in many applications in helioseismology (Duvall et al, 1993;Gilles et al, 1997), acoustics Lobkis and Weaver, 2001;Larose et al, 2004), oceanography (Roux and Kuperman, 2004;Sabra et al, 2005c), active seismic experiments (Bakulin and Calvert, 2006;Mehta et al, 2007) and seismology with the correlation of seismic coda (Campillo and Paul, 2003) or seismic noise (Shapiro and Campillo, 2004).…”

Application of damage detection methods using passive reconstruction of impulse response functions

“…If the measured field is not perfectly diffuse, then the function will not match as closely. For example, if the noise sources are on only one side of the sensors, then the correlation function will be onesided if there are no other reflections [18]. Additionally, the longer the amount of time used in the correlation the more the coherent signals are recovered.…”

“…Notable research in advancing the use of ambient noise in passive applications of SHM evolved out of leading research work in ocean acoustic and seismology [16][17][18][19]. The advantage to using existing noise sources in the ocean removes the limitations and barriers of active sonar that create concerns for ocean wildlife.…”

Characterization of ambient seismic noise near a deep geothermal reservoir and implications for interferometric methods: a case study in northern Alsace, France

“…For tomography applications, noise sources should be homogeneously distributed (Lobkis and Weaver 2001;Roux et al 2005). Under this assumption, only the sources located in a narrow area along the continuation of the path joining the two stations contribute to the recovered Green's function (Roux et al 2004;Sabra et al 2005c;Larose 2005;Gouédard et al 2008). For applications that monitor time-dependent perturbations of the medium, noise sources may be inhomogeneously distributed, but in this case, they must be repeatable.…”