Time-to-depth conversion and seismic velocity estimation using time-migration velocity |

where is the right-hand side. In numerical examples, we tried and . This method allows larger time steps than the finite difference, and has the adjustable parameter .

For step 2, we use a Dijkstra-like solver introduced in Cameron et al. (2007). It is an efficient time-to-depth conversion algorithm motivated by the Fast Marching Method (Sethian, 1996). The input for this algorithm is and the outputs are the seismic velocity and the transition matrices from time-domain to depth-domain coordinates and . We solve the eikonal equation with an unknown right-hand side coupled with the orthogonality relation

The orthogonality relation means that the image rays are orthogonal to the wavefronts. Such time-to-depth conversion is very fast and produces the outputs directly on the depth-domain grid.

Time-to-depth conversion and seismic velocity estimation using time-migration velocity |

2013-03-02