An improved reverse time migration for subsurface imaging in layered media

An improved reverse time migration (RTM) method is proposed for borehole radar imaging in the subsurface scenarios with layered media. The time gating function is designed and applied to the incident wave field and scattering wave field for each imaging point, which strengthens the correlation between the wave fields in time domain. A normalized zero-offset cross-correlation with gated samples is conducted and used to weight the result of RTM. The improved approach is compared with the conventional RTM, back projection method, and Stolt migration algorithm with synthetic data. The results demonstrate the developed approach is superior to the conventional methods in locating targets and robust in complex subsurface environments.