In several domains of applied geophysics, surface, and guided waves are considered as a source of information for characterizing the near surface, which in a marine environment includes the seabed. By contrast, in exploration seismic surveys, these waves have traditionally been regarded as coherent noise that should be filtered out as soon as possible. The authors consider that surface and guided waves are not noise but a signal that can be lifted from the seismic record and exploited for a variety of well-established geophysical solutions. Surface and guided waves constitute a large part of the recorded energy and with proper acquisition, analysis, and inversion they can be used to characterize the near surface with surprisingly high resolution. In this role, they can provide valuable information for tasks such as perturbation correction—adjustment for near-surface traveltime distortions. They can also be used for velocity and geological modeling. In this article, the authors discuss a workflow for the analysis and joint inversion of surface and guided waves in both land and offshore seismic data.

Land seismic data are contaminated by surface waves ͑or ground roll͒. These surface waves are a form of source-generated noise and can be strongly scattered by near-surface heterogeneities. The resulting scattered ground roll can be particularly difficult to separate from the desired reflection data, especially when this scattered ground roll propagates in the crossline direction. We have used seismic interferometry to estimate scattered surface waves, recorded during an exploration seismic survey, between pairs of receiver locations. Where sources and receivers coincide, these interreceiver surface-wave estimates were adaptively subtracted from the data. This predictive-subtraction process can successfully attenuate scattered surface waves while preserving the valuable reflected arrivals, forming a new method of scattered ground-roll attenuation. We refer to this as interferometric ground-roll removal.

While in other domains of applied geophysics the surface‐wave is considered a source of information for near‐surface characterization, in the seismic industry the so‐called ground roll has been traditionally regarded only as coherent noise to be filtered out as soon as possible. This difference of perspective is mainly due to the limitations of conventional land acquisition. The Rayleigh waves, which constitute a large part of the recorded energy, can be acquired properly, analysed and inverted to characterize the near‐surface with a surprisingly high resolution, even in large 3D surveys, with point receiver acquisition. Surface waves can play a new role: they contribute to a better near‐surface characterization for the perturbation correction and can be used for velocity modelling and geological modelling. Their proper identification enables alternative filtering strategies. Surface waves are not coherent noise but a signal that can be lifted from the seismic record and exploited in a variety of well‐established geophysical solutions. In this paper we discuss a workflow for the analysis, inversion and attenuation of surface waves with 3D land data, showing examples from a land 3D survey in Egypt.

Standard procedures for dispersion analysis of surface waves use multichannel wavefield transforms. By using several receivers, such procedures integrate the information along the entire acquisition array. That approach improves data quality and robustness significantly, but its side effects are spatial averaging and loss of lateral resolution. Recently, a new approach was developed to address that issue and maximize lateral resolution. The new method uses multioffset phase analysis to detect and locate sharp lateral variations in velocity. By using the phase analysis approach, the number of usable channels can be maximized, thereby gaining data quality without compromising lateral resolution. In fact, such preliminary data analysis also allows selection of the appropriate traces on which to perform multichannel processing. Such multioffset phase analysis can be enhanced by f-k filtering, which assures the selection of only one wave-propagation mode, and by a statistical analysis that takes advantage of data redundancy of multishot data, usually collected, for example, in land refraction surveys. Moreover, this novel statistical method with f-k filtering can be used to retrieve a dispersion curve, in principle, for each receiver location. The quasi-continuous pseudoimage of shear-wave velocity as a function of offset and frequency allows a characterization of lateral variations in velocity, whether they are sharp or smooth