On the Reliability of Direct Rayleigh-Wave Estimation From Multicomponent Cross-Correlations
Seismic interferometry is routinely used to image and characterize underground geology. The vertical component cross-correlations (CZZ) are often analysed in this process; although one can also use radial component and multicomponent cross-correlations (CRR and CZR, respectively), which have been shown to provide a more accurate Rayleigh-wave Green’s function than CZZ when sources are unevenly distributed. In this letter, we identify the relationship between the multicomponent cross-correlations (CZR and CRR) and the Rayleigh-wave Green’s functions to show why CZR and CRR are less sensitive than CZZ to non-stationary phase source energy. We demonstrate the robustness of CRR with a synthetic seismic noise data example. These results provide a compelling reason as to why CRR should be used to estimate the dispersive characteristics of the direct Rayleigh wave with seismic interferometry when the signal-to-noise ratio is high.
Xu, Zongbo and Mikesell, T. Dylan. (2017). "On the Reliability of Direct Rayleigh-Wave Estimation From Multicomponent Cross-Correlations". Geophysical Journal International, 210(3), 1388-1393. http://dx.doi.org/10.1093/gji/ggx228