Abstract: A method of attenuating multiples in signals recorded during a marine seismic survey is described using a multi-component data set of the survey and summing selected components of the data set after filtering components with a filter that combines recorded data from more that one receiver location and operates indiscriminately on P- and S-wave data.

Abstract: A method for determining a representation of an anisotropic earth formation is described, wherein the inversion step for generating the representation from recorded seismic data is performed using several values of a pre-defined anisotropy parameter addition to components of the moveout velocity. The anisotropy parameter is preferably introduced into the moveout equation or dispersion relation, which in turn is used in the inversion process.

Abstract: The signature of an energy source is determined from an inverse scattering Born series representing multiple reflected energy. The series comprises a polynomial in the inverse of the signature and has recorded data as the first term. The series is truncated, preferably to the first two terms to permit an analytical determination of the signature to be found. The value of the inverse signature which minimises the energy represented by the sub-series is found and this corresponds to the desired source signature. An iterative scheme may be adopted to improve the match to the actual signature so as to take into account the errors caused by truncating the scattering series.

Abstract: Methods and apparatus are described for reducing the multiple energy in seismic signal acquisitions, in particular for sea bottom acquisition. The method is based on the scattering Born series for free-surface multiples. It is characterized in that only terms of the even sub-series of the scattering Born series are considered for determining the multiple-free data.