Full-azimuth angle gather extraction based on optimized optical flow

In seismic imaging and hydrocarbon exploration, full-azimuth common-imaging-point angle gathers are important, as they effectively characterize and reveal the propagation behavior and reflection signatures of seismic waves in subsurface media. Residual curvature analysis of angle gathers allows high-precision tomographic inversion and further improves imaging accuracy. The traditional Horn–Schunck (HS) optical flow method is prone to noise interference from various directions when calculating wavefield directions, and its computational accuracy and noise resistance need improvement. To address these limitations, this study investigates an optimized method to extract full-azimuth common-imaging-point angle gathers by developing a modified HS optical flow approach based on a fractional-order objective function. This method assigns direction-specific weights to both the data term and the regularization term, thereby further constraining the wavefield direction and enhancing computational accuracy and noise resistance. Tests on complex models and field data demonstrate that the proposed method extracts higher-quality full-azimuth common-imaging-point angle gathers in the presence of complex structures and low signal-to-noise ratio field data. The method significantly improves wavefield direction estimation and noise resistance, thereby validating its effectiveness.