PS-wave prestack time migration using scattered-wave interference stacking

Three-component vibroseis acquisition has been widely used in desert regions due to its operational convenience; however, the resulting records suffer from weak effective signal energy, low signal-to-noise ratio (SNR), and pronounced “black triangle” artifacts, which severely hinder the imaging and inversion of PS waves. To address this issue, an interferometric stacking prestack time migration method specifically designed for low-SNR PS-wave data is proposed. Based on the time–distance relationship among the source, receiver, and imaging point, a mapping relationship is established between amplitude samples in the input seismic traces and those in the target PS-wave common-image gathers. Incorporating PS scattered-wave traveltime, an interferometrically stacked seismic trace is constructed to enhance phase-consistent energy while suppressing noise. Furthermore, the influence of the initial velocity model on the interferometric PS-wave gathers is analyzed theoretically. Tests on synthetic and field data demonstrate that the proposed method has low dependence on the initial velocity model, delivers high-quality PS-wave common-image gathers under low-SNR conditions, and significantly improves PS-wave migration accuracy, thereby providing effective support for elastic wave exploration in desert regions.