Diffraction Imaging by Prestack Reverse-time Migration in the Dip-angle Domain

dip-angle is derived by local Radon transform in depth and midpoint coordinates, followed by an averaging over space-shifts. We propose to incorporate space-shift extended reverse-time migration (RTM) and dip-angle decomposition for imaging small-scale structural elements, considered as seismic diffractors. A suitable dip-angle construction of a specularity filter rejects the dominant reflectors and enhances diffractors and other non-specular image content. The filter exploits a clear discrimination in dip between specular reflections and diffractions. We demonstrate the dip-angle filter with 2D synthetic examples, and show its robustness against migration velocity errors. Our method for diffraction imaging delivers space-shift and angle-domain image-gathers, simultaneously, and obviously enrich the processed material on the interpreter’s desk.