Multicomponent acquisitions offer the opportunity to form elastic migration images and to estimate elastic parameters of the subsurface. Compared with better constrained P-wave velocity inversions, it is more difficult to estimate the S-wave velocity due to strong nonlinearities introduced by converted S-waves. We have developed an iterative S-wave velocity inversion method guided by image regi...

Provided the velocity of the medium is known and the the medium does not allow different reflectors to have identical surface seismic measurements that persist under small perturbations of the medium, map migration achieves a one-to-one mapping from surface seismic data to the subsurface seismic image by using the slopes in addition to the location (and time) of the events in the data. In this ...

Cells exhibit a biphasic migration-velocity response to increasing adhesion strength, with fast migration occurring at intermediate extracellular matrix (ECM) concentration and slow migration occurring at low and high ECM concentration. A simple mechanical model has been proposed to explain this observation, in which too little adhesion does not provide sufficient traction whereas too much adhe...

Prestack migration methods based on data binning produce kinematic artifacts, i.e. coherent events not corresponding to actual reflectors, in the prestack image volume, when the medium is strongly refracting. Shot-geophone (“survey sinking”) migration, on the other hand, does not produce such artifacts when events to be migrated arrive in the data along non-turning rays. In contrast to prestack...

Wave-equation migration velocity analysis is based on the linear relation that can be established between a perturbation in the migrated image and the corresponding perturbation in the slowness function. Our method formulates an objective function in the image space, in contrast with other wave-equation tomography techniques which formulate objective functions in the data space. We iteratively ...