Synchronized seismic signal acquisition method and device

Abstract

Method and device intended for synchronized acquisition of seismic signals by one or more acquisition units suited for seismic signal digitizing, allowing to obtain, for each signal, a series y[n] of samples of these signals readjusted from a reference time on, from a first series x[n] of digitized samples of this seismic signal produced from any initial time prior to the reference time. The method essentially comprises detecting a synchronization signal indicative of this reference time (T,), measuring the effective time difference (D) between the reference time and the initial time, determining coefficients of a digital filter (F) suited to compensate for the fractional part (d) of the measured effective time difference, and applying this compensation digital filter to the first series of samples, which allows to obtain a series of digitized samples readjusted from the reference time. In order to accelerate determination of the filter coefficients depending on the difference D observed, the coefficients of a certain number of intermediate filters corresponding to determined fractions of the sampling interval are preferably precalculated. The method can be applied for seismic prospecting or monitoring, earthquake detection, etc.