Interferometric Interpolation and Extrapolation of Sparse OBS and SSP Data

We present the theory and numerical results for interferometrically interpolating and extrapolating ocean bottom seismic (OBS) and surface seismic profile (SSP) data. For the interpolation of OBS data we use the combination of a natural Green’s function (i.e. OBS shot gather) and a model-based Green’s function for the water-layer model. Results show that the aliased OBS data with 80 meter geophone intervals can be accurately interpolated to 8 meter intervals. A key to accurate interpolation is a matching filter applied after interferometric interpolation. Similarly, OBS and SSP data extrapolation employs a natural Green’s function and a model-based Green’s function. Results show that the OBS and SSP receiver apertures can be more than doubled in width by applying interferometric extrapolation. The results suggest that a sparse OBS or SSP survey can yield much more information about the reflectors if data are interpolated and extrapolated by interferometry. This assumes that the sources are located far outside and inside the recording aperture.