Seismic Imaging with and without Velocity

A new type of seismic imaging, based on Feynman path integrals for waveform modeling, is capable of producing accurate subsurface images without precise knowledge of a reference velocity model.<br>Instead of the usual optimization of the semblance objective function, a weighted summation over all representative curves avoids the need of velocity analysis, with its common difficulties of subjective and time consuming manual picking.<br>The path integral imaging can be applied to stacking to zero-offset, time- and depth migration.<br>In all these cases, a properly defined weighting function plays a vital role, to emphasize contributions from traveltime curves close to the optimal one and suppress contributions from unrealistic curves.<br>The path integral method is an authentic model-independent technique, in the sense that there is strictly no parameter optimization or estimation involved.<br>Synthetic and real data examples shows that it has the potential of becoming a fully automatic imaging technique.<br>