Angle-domain reverse time migration with full illumination compensation

Abstract

Reverse time migration (RTM) can effectively image complex subsurface structures but often distorts amplitudes in stacked migrated images and angle-domain common-image gathers (ADCIGs) due to uneven illumination effects. An angle-domain RTM method compensates for these distortions using an optimal angle-dependent illumination matrix derived from the point spread function. This approach uses full-wave Green's functions and efficiently computes point spread functions based on excitation amplitude and time of downgoing wavefields. Although additional finite-difference solvers are required at receiver positions that do not coincide with source positions, the method efficiently produces relatively amplitude-preserving ADCIGs. Synthetic and field tests significantly improve stacked image amplitudes and ADCIGs, particularly in complex overburden scenarios.