3-D traveltime computation using interpolation of traveltime perturbations

Abstract

Summary Many methods of accurately computing traveltimes of seismic waves in complex models are based on linear traveltime interpolation, assuming that the traveltime is linear along each boundary of cells. Actually, traveltime of waves along a boundary of cells may not be linear. The assumption of linear traveltime may result in large errors in the computed traveltime. We may regard the traveltime at a point as a reference traveltime propagating in an equivalent homogeneous medium plus its perturbation, the difference of the reference traveltime and the true one. Base on the assumption that the traveltime perturbation, instead of the traveltime, is linear along each boundary of cells, we propose a new method for traveltime computation in 3-D complex models and combine it with the group marching algorithm. The numerical experiment shows that the new method is able to achieve higher accuracy than that based on linear traveltime interpolation.