Traveltime calculation has wide applications in seismology and seismic exploration.The fast marching method is a technique used for rapidly calculating seismic traveltimes.However,Traditional methods can introduce significant errors due to the large curvature of the wavefront near the source.To solve this issue,we propose an effective-slowness-based fast marching method to calculate seismic traveltimes.This method adopts the idea of"straight-line-for-curved-line",defining the effective slowness as the quotient of traveltime and the straight-line distance from the point to the source.This approach effectively transfers the complexity of the traveltime or curvature partially to the distance term that has an analytical solution,resulting in smaller curvature and smoother distribution of equivalent slowness.We discretize the effective slowness using the differential operator,and then transform it into the traveltime to achieve higher accuracy.Finally,the effectiveness of this algorithm is validated through precision and efficiency analysis using numerical examples.
维普
万方数据