Interferometric Interpolation and Extrapolation of Sparse 2D OBS Data

We present the theory and numerical results for interferometrically interpolating and extrapolating ocean bottom seismic (OBS) 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. Synthetic and field data results show that the aliased OBS data with large receiver intervals can be accurately interpolated to smaller intervals. A key to accurate interpolation is a local image matching filter applied after interferometric interpolation. Similarly, OBS data extrapolation employs a natural Green’s function and a model-based Green’s function. Results show that the OBS receiver apertures can be more than doubled in width by applying interferometric extrapolation. This suggests that a sparse OBS survey can yield much more information about the reflectors if data are interpolated and extrapolated by interferometry. This assumes that the sources are located both far outside and within the recording aperture.