Target-oriented Data-Domain Least-Squares Reverse Time Migration

Least-squares reverse time migration (LSRTM) is a migration method for retrieving subsurface reflectivity using linear inversion theory. Compared to traditional imaging methods, LSRTM offers higher resolution and amplitude preservation. However, the computational cost of LSRTM in the data-domain is high and inevitably leads to the creation of imaging artifacts due to internal multiples. In this study, we propose a target-oriented data-domain LSRTM based on the first-order velocity-stress equation and the Marchenko equation. By two steps of source redatuming and receiver redatuming, this method extrapolates the wavefield from the acquisition surface to beneath the complex overburden, eliminating the impact of multiple scattering within the overburden and achieving target-oriented imaging. Numerical result shows that this method effectively mitigates imaging artifacts caused by internal multiples within the overburden, thus enhancing imaging quality.