Abstract: This invention relates to a method for processing seismic data comprising a collection of seismic traces with different offsets, comprising the steps of: a) breaking up one or several first trace(s) of the collection of seismic traces into a series of trace segment's according to a predetermined segmentation interval; b) defining a series of expansion coefficients, each expansion coefficient being associated with a segment of the first trace or traces; c) applying the associated expansion coefficient to each segment of the first trace or traces; d) comparing the first trace or traces thus expanded with a second trace from the collection of seismic traces to evaluate their similarity; e) repeating steps b), and d) with a new series of expansion coefficients, f) determining an optimum series of expansion coefficients that maximizes the similarity between the first expanded trace and the second trace in order to obtain one or several corrected first trace(s).

Abstract: A method of seismic processing for obtaining information on the geophysics of the subsoil includes acquiring seismic traces at at least one point on the surface of the subsoil or in the subsoil, the seismic traces corresponding on each occasion to two perpendicular components of a shear wave emitted into the subsoil and reflected by different interfaces therein; applying a succession of transformations (?) at least to a temporal portion of the traces for each of these assumptions, determining the value of a parameter representative of the coherence/similarity between the result traces obtained in this way; and election as a function of the values obtained in this way that one of the hypotheses which is considered as being most representative of the subsoil, the two result traces obtained for said hypothesis being compensated traces of the subsoil birefringency.

Abstract: This invention relates to a method for processing seismic data comprising a collection of seismic traces with different offsets, comprising the steps of: a) breaking up one or several first trace(s) of the collection of seismic traces into a series of trace segments according to a predetermined segmentation interval; b) defining a series of expansion coefficients, each expansion coefficient being associated with a segment of the first trace or traces; c) applying the associated expansion coefficient to each segment of the first trace or traces; d) comparing the first trace or traces thus expanded with a second trace from the collection of seismic. traces to evaluate their similarity; e) repeating steps b), c) and d) with a new series of expansion coefficients, f) determining an optimum series of expansion coefficients that maximizes the similarity between the first expanded trace and the second trace in order to obtain one or several corrected first trace(s).

Abstract: The invention relates to a method of seismic processing for obtaining information on the geophysics of the subsoil, the method comprising the following steps: a) acquiring seismic traces at at least one point on the surface of the subsoil or in the subsoil, the seismic traces corresponding on each occasion to two perpendicular components of a shear wave emitted into the subsoil and reflected by different interfaces therein; b) applying a succession of transformations (?) at least to a temporal portion of the traces, which transformations are the inverses of the transformations that it is assumed that the wave has encountered on passing through a succession of layers in the subsoil, this operation being repeated for different assumptions concerning birefringence in the various layers; c) for each of these assumptions, determining the value of a parameter representative of the coherence/similarity between the result traces obtained in this way; and d) selecting as a function of the values obtained in this way t

Abstract: A method of processing seismic traces corresponding to two modes of propagation in the subsoil, the method being characterized by the following steps: determining at least one pair of correlated events from the seismic traces corresponding to the two modes respectively; determining the ratio of the differences between the vertical travel times Ts and Tp in the S domain and in the P domain, corresponding to said correlated pairs of events; and determining the values of Ts and Tp over the time interval defined by the two pairs of correlated events so that throughout said time interval, the ratio rt=Ts/Tp is equal to the ratio Vp/Vs of the speeds in the P domain and in the S domain, and so that the mean value of said ratio r over said time interval corresponds to the ratio of the differences between the vertical travel times corresponding to the pairs of correlated events.

Abstract: Seismic acquisition apparatus comprising a plurality of detectors (s1, s2, etc.) each constituted by one or more seismic sensors, combiner means which generate at least one seismic trace corresponding to a group of detectors by combining the signals output thereby, and memory means for storing the seismic traces generated in this way, the apparatus being characterized in that it includes seismic preprocessor means (&mgr;P1, &mgr;P2, etc.) for re-phasing the signals output by the detectors prior to the signals being combined and/or prior to accidental noise on said signals being eliminated.

Abstract: A method of correcting a seismic signal s(t) provided by a vibration sensor (100) in response to at least one emission signal F(t) produced by a least one seismic vibration generator (200). The real emission signal F(t) differs in phase and amplitude relative to a reference emission signal F(t). The correction method of the invention consists in determining the phase difference .DELTA..phi.(f) and the amplitude ratio A(f) between the real emission signal F(t) and the reference emission signal F(t) as a function of frequency f, and in applying the seismic signal s(t) from the vibration sensor (100) to a filter (304) whose response is defined in phase and amplitude respectively by -.DELTA..phi.(f) and by 1/A(f).

Abstract: In a method and device for the study of surface layers and subjacent layers of interest, the device comprises receivers and at least two transmission sources spaced at a distance such that a set of traces produced by one of the transmission sources does not interfere with a set of traces produced by the other transmission source when the two sets of traces are on the same time-section.