Kinematic redatuming using common emergence rays

Abstract

Redatuming is the process of generating seismograms corresponding to sources and receivers located on an imaginary datum using data from sources and receivers located at different datum. The most rudimentary version of this process is very common in seismic processing in the form of static corrections. On the other side of the complexity spectrum lie redatuming methods relying on numerical backpropagation of the recorded data to the new datum using the wave equation. Herein I propose a method slotted in between these two extrema. The method redatumes each sample in the data by assigning it new traveltime as well as new lateral locations of the redatumed source and receiver to a new datum below the original acquisition surface. The method relies on identifying samples in the data that share the same emergence rays based on horizontal slownesses (local slopes). One can view the method as a generalisation of static corrections to account for non-vertical rays.