MSFM-Based Seismic Traveltime Calculation Using Coarse-Grid Interpolation

Computing seismic traveltime constitutes an essential task for seismic imaging and inversion processes. Accurate traveltime computation provides essential parameters for simulating seismic wave propagation, locating seismic sources, establishing velocity models, and seismic imaging. Therefore, a method for calculating seismic traveltime that is accurate, efficient, and stable holds significant research and practical value. The Multi-Stencils Fast Marching (MSFM) method improves upon the Fast Marching Method by employing multiple stencils to enhance accuracy, addressing the issue of significant errors in diagonal directions. However, its computational complexity increases exponentially with the number of stencils, leading to efficiency bottlenecks in large-scale models. This study proposes an enhanced MSFM method incorporating coarse-grid interpolation to compute seismic traveltime in complex velocity models. The technique extends the conventional MSFM framework by refining its narrowband expansion mechanism, utilizing coarse-grid technology to interpolate values from coarse-grid nodes to fine-grid nodes, thereby improving computational efficiency and reducing memory usage. The improved MSFM algorithm is validated using multiple models, demonstrating that it significantly enhances computational efficiency while maintaining good accuracy.