DECOMPOSITION OF THE LAPLACIAN FILTER OPERATOR FOR REVERSE TIME MIGRATION

Reverse time migration is considered as an effective approach to obtain the images of layers, but it usually produces some artifacts in the images. Applying a Laplacian filter is a conventional and effective approach to improve these images. In this work, the Laplacian operator is decomposed mathematically. Based on this decomposition, the reason why the Laplacian filter can improve images is investigated thoroughly, and the work part is identified. Then we discard the useless part and employ the work part to form a new imaging condition. At first, shown in a one-shot numerical experiment, the proposed imaging condition can simultaneously remove the low-and high-frequency artifacts effectively. Then, the Sigsbee2A velocity model is employed as a synthetic example to verify the proposed imaging condition. The numerical results show that the proposed imaging condition can effectively govern the principal energy in wave fields and damp artifacts in angle domain.