An improved bilinear interpolation travel-time ray-tracing method

Linear travel-time interpolation ray-tracing (LTI) is a kind of ray-tracing technology which has a global searching ability and a relatively high computational efficiency. However, for near offsets LTI's linear hypothesis usually causes poor computational accuracy and the unreasonable ray-tracing path. In order to overcome these issues, we propose an improved bilinear travel-time interpolation algorithm. This algorithm optimizes the scanning method to determine the wave-front and propagation direction of seismic waves, traces the shortest ray-path, and uses the dynamic variable density mesh mode to improve the travel-time accuracy effectively especially in near offsets. At the same time, the rapid determinant conditions and the simplified formulas effectively reduce the computational complexity and improve the computational efficiency. Theoretical model tests show the effectiveness of the method.