Lifting Scheme of Plane-Wave Decomposition for Separating Diffraction

Separating diffraction patterns helps in providing detailed information on geological structures. However, the amplitude of weak diffraction is difficult to preserve and often destroyed during the separation process, particularly when the diffraction is tangential to the reflection. Estimating an accurate local slope can effectively predict the reflection for separating diffraction. Conventional plane-wave decomposition (PWD) method directly calculates the slope of the stack section. This leads to aliasing between reflection and diffraction slopes, resulting in the loss of diffraction information. Therefore, we propose a PWD lifting scheme that mainly focuses on the slope-mapping operator between stack and migration sections. We first calculated the slope in the migration section by the conventional PWD method and then transferred it from the migration to the stack section using the mapping operator, which was derived by the migration principle. Because the diffraction waves converge in the migration section, their slopes were not estimated and aliased with the reflection slope. This method can accurately estimate the slope and effectively distinguish between diffraction and reflection. Synthetic and field data applications demonstrate that the proposed method is effective in separating diffraction and can preserve the diffraction amplitude, even when the diffraction is tangential to the reflection.