Multichannel analysis of passive surface waves based on crosscorrelations

Abstract

Passive seismic methods in highly populated urban areas have gained much attention from geophysics and civil engineering communities because traditional seismic surveys, especially in complex urbanized environments, might be improperly applied. In passive seismic methods, directional noise sources will inevitably bring azimuthal effects and spatial aliasing to dispersion measurements due to the fact that true randomness of ambient noise cannot be achieved in reality. To solve these problems, multichannel analysis of passive surface (MAPS) waves based on long noise sequence crosscorrelations is proposed. We have introduced a hybrid method of seismic interferometry and the roadside passive multichannel analysis of surface waves (MASW) using crosscorrelation to produce common virtual source gathers from 1 h multichannel noise records. Common virtual source gathers are then used to do dispersion analysis with an active scheme based on phase-shift measurement. Synthetic tests demonstrated the advantages of this method with azimuthal adjustment and dispersion imaging for directional noise source distribution. Two field applications were conducted, and results from the roadside passive MASW, MAPS, and spatial autocorrelation method were compared. Our study indicated the superiority of MAPS over the roadside passive MASW on the validity of azimuth detection, feasibility of combining the active MASW and MAPS, and accuracy in determining dispersion energy trends, especially at a relative low-frequency range ([Formula: see text]) in urban areas.

Passive processing of active nodal seismic data: Estimation of V<sub>P</sub> / V<sub>S</sub>-ratios to characterize structure and hydrology of an alpine valley infill

“…Two large 4WD trucks were used for deployment and transporting the source, and their movements along the profile also generate surface wave energy. Many other studies find traffic noise to be a dominant ambient noise source at local scales (Behm et al, 2014;Riahi and Gerstoft, 2015;Chang et al, 2016), and specifically designed surveys are used for traffic noise imaging in urban areas (Cheng et al, 2016). For our data set, active shooting during the day is also regarded as a major contributor to the ambient 20 seismic wave field.…”

Hydropower Dam State and Its Foundation Soil Survey Using Industrial Seismic Oscillations

“…If, for some passive seismic methods that are based on The advancement of seismic equipment and the development of a methodological base have led to the passive seismic methods and ambient vibration testing becoming increasingly important in structural health and safety monitoring [10][11][12][13][14]. If, for some passive seismic methods that are based on the cross-correlation or convolution of ambient noise, a high level of microseisms is necessary [15][16][17]. For other methods that determine the natural frequency of a structure [3,10,18] or are based on spectral analysis of the natural ambient seismic noise [19][20][21], a high level of microseisms is a negative factor that impedes the data processing.…”

Automated Data Selection in the Tau–p Domain: Application to Passive Surface Wave Imaging

“…Considering a laterally homogeneous dissipative medium, we generate the passive seismic wavefield by summing of modal components (Aki and Richards 1980). We closely follow the noise simulation procedure described in Cheng et al (2016). The medium is a two-layer model (Table 1), whose properties are taken from Le Feuvre et al 2015and Cheng et al (2016).…”

“…Interferometry techniques can enhance coherent signals from ambient energy and minimize incoherent phase-shift during dispersion measurements because cross-correlation does not reconstruct for unrelated signals (e.g., O'Connell and Turner 2011; Boschi et al 2013;Le Feuvre et al 2015). Cheng et al (2016) proposed a hybrid method, that combines cross-correlation and MASW method, called multichannel analysis of passive surface waves (MAPS).…”