Approximate plane-wave decomposition and de-multiple processing of point-source line-profile data by the 1-D Fourier transform

De-multiple, or de-ghosting, of ocean bottom point-source data recorded alo ng a line profile may be performed by wavefield decomposition giving upgoin g waves just above or below the sea floor. This process has also been named dual field summation. In general, this and other related algorithms may be formulated in the frequency wavenumber domain, hence, raising the question of how we should transform two component (2-C) line profile data from a po int-sourer experiment to the wavenumber domain when we cannot assume that t he subsurface is essentially one dimensional. In this paper we investigate the effect of applying the 1-D Fourier transfo rmation in the wavefield decomposition-based multiple attenuation scheme fo r point-source pressure data. Usually, the 1-D Fourier transformation appli es only to 2-D wave equation processing (line source data). We find, howeve r, that for the de-multiple process for 2-C point-source data, the I-D Four ier transformation is sufficient. This approximate plane wave decomposition before de-multiple works satisfactorily except for very steep propagation angles (critically refracted waves). Numerical examples are used to illustr ate and support this conclusion.