An Improved Method of Linear Travel-Time Interpolation Ray Tracing Algorithm

The linear travel-time interpolation algorithm is improved by the method of ray tracing based on finite difference scheme of eikonal equation. It can simulate the more complex medium. Using the algorithm to calculate travel-time and paths of tracing rays, it is more rapid and accurate than the other conventional methods. The linear travel-time interpolation ray tracing algorithm has a drawback: rays cannot go round the low velocity area if the launching point, the receiving point and the low velocity area distribute on the same column (row). Aiming at the drawback, an improved algorithm is proposed on the basis of researching reconstruction theories. The given algorithm adopts a cross-scanning strategy to carry out forward processing and uses discrete points as the secondary sources to simplify backward processing. The numerical simulation experiments show that the rays can go round the low velocity areas located in the same column (row) of the launching points and the receiving points. Rays scan over the global region only once.