Wave-equation migration velocity analysis (WEMVA) is a velocity estimation technique designed to invert for velocity information using migrated images. Its capacity for handling multi-pathing makes it appropriate in complex subsurface regions characterized by strong velocity variation. WEMVA operates by establishing a linear relation between a velocity model perturbation and a corresponding mig...

Prestack wave equation migration using the double square root equation produces prestack image volumes free of artifacts, even in the presence of multipathing due to complex structure. In particular image gathers in angle or offset ray parameter are flat at correct velocity, and gathers in offset are concentrated at zero offset. Differential semblance measures the deviation from flatness or con...

Velocity models used for wavefield-based seismic imaging represent approximations of the velocity characterizing the area under investigation. The real subsurface velocity can at best be approximated by the combination of a known background velocity and unknown multi-scale heterogeneities. Here, we model the multi-scale heterogeneity assuming a fractal behavior and compare this type of heteroge...

Echo-reconstruction techniques for non-intrusive imaging have wide application, from subsurface and underwater imaging to medical and industrial diagnostics. The techniques are based on experiments in which a collection of short acoustic or electromagnetic impulses, emitted at the surface, illuminate a certain volume and are backscattered by inhomogeneities of the medium. The inhomogeneities ac...

In order to produce an accurate depth migration of a seismic line, one needs an accurate velocity model. This model should reflect the lithology and lithostatic load that the rocks have experienced through burial and deformation. If we understand the geometry of these rocks, and their behaviour upon deformation, we can produce a more accurate velocity model. Performing palinspastic restoration ...

We apply 2-D wave-equation prestack depth migration to a North Sea basalt dataset. High velocity and impedance contrasts across a basalt layer causes low P-wave reflection signal-to-noise ratio under the basalt. We first migrate the P-wave data with a provided depth velocity model, and then replace sub-basalt P-wave velocity with a simple estimate of shear wave velocity and migrate locally-conv...