Deabsorption prestack time migration from rugged topography

Abstract

Abstract We developed a modified topography prestack time migration (PSTM) scheme that can improve the imaging resolution by applying effective Q to topography migration. The computation of the traveltime at each imaging location in the migration is based on the floating datum smoothed by rugged topography. Unlike the common quality factor Q, the effective Q only determines the frequency-dependent amplitude and the traveltime at a single imaging location, which enables us to establish a Q model in an inhomogeneous medium. Hence, we can acquire the effective Q using a scanning technology according to the width of the frequency band and signal-to-noise ratio of the imaging gathers. The proposed migration method can be integrated into the conventional topography migration workflow. Synthetic and three-dimensional (3D) field datasets indicate that the proposed deabsorption PSTM from rugged topography is effective.