Systematic Recovery of Instrumental Timing Errors Using Interferometric Surface Waves Retrieved from Large N Seismic Arrays

Abstract

Timing errors are a notorious problem in seismic data acquisition and processing. A technique is presented that allows such timing errors to be recovered in a systematic fashion. The methodology relies on virtual- source responses retrieved through the application of seismic interferometry (SI). In application to recordings of ambient seismic noise, SI involves temporal averaging of time-windowed crosscorrelation measurements. The retrieved interferometric responses are typically dominated by surface waves. Under favorable conditions, these interferometric responses therefore approach the surface-wave part of the medium's Green's function. Additionally, however, its time-reverse is often also retrieved. This implies time-symmetry of the time-averaged receiver-receiver crosscorrelations. In this study, this time-symmetry is exploited: by comparing the arrival time of the direct surface wave at positive time to the arrival time of the direct surface wave at negative time for a large a number of receiver- receiver pairs, relative timing errors can be determined in a weighted least-squared sense. The proposed methodology is validated using synthetic data. The results hold particular promise for large N seismic arrays.