oa Keynote Presentation - Coordinate-Independent Extended Images for Wave-Equation Migration Velocity Analysis

Coordinate-independent extended images for wave-equation migration velocity analysis Paul Sava, Center for Wave Phenomena, Colorado School of Mines Wavefield-based migration velocity analysis using the semblance principle requires computation of images in an extended space in which we can evaluate the imaging consistency function of overlapping experiments. Usual industry practice is to assemble those seismic images in common-image-gathers (CIG) which represent reflectivity function of space, e.g. depth, and extensions, e.g. offset, cross-correlation lags in space and time, or the reflection angles. Depending on the type of extension, the CIGs represent correct imaging if the seismic events are either flat or focused, indicating correct wavefield reconstruction from the sources and receivers.