The Forward Simulation Of Iteration Segment By Segment Ray-Tracing In 3D Seismic Gather

Seismic ray-tracing problem and inversion of wave equation is an important research topic in the geophysics and geophysical prospecting, The ray-tracing problem is not only an efficient method of studying seismic propagation in the random velocity distribution media, but also it plays an important role in the seismic tomography and pre-stack depth offset. The precision and speed of ray-tracing will influence of the results of tomography and pre-stack depth offset.The ray-tracing method is based on a geological model, to the geological model tradition description, generally used mesh or layered structure described. For the simple geological model, classic description of the layered structure has its unique advantages. Model Description convenient, ray-tracing is fast, when to complex model description can encounter the difficulty, but these questions all may find the corresponding solution.Based on Snell law and Fermat principle, the two-point ray-tracing method for two dimensional and three dimensional arbitrary interface is studied in this paper. First, by use of one order Taylor incomplete expansion, a positive definite formula, which is suitable to calculate reflection or refraction point in two-dimensional and three-dimensional constructs, is obtained. Then, starting from an arbitrary given initial ray path, ray-tracing is iteratively calculated segment by segment. The procedure is kept on until the sum of adjustment quantity in the whole path is in the range of precision and the last iterative result is regarded as final two dimensional or three dimensional ray path. Now, the iterative ray-tracing segment by segment in two dimensional or three dimensional construct is finished.Numerical tests show that this algorithm is fast and its calculating precision can reach any requirements needed. Iterative ray-tracing method segment by segment for 2-D and 3-D media and its application problems, and provided solving-method. The improvement of algorithm improve the efficiency of ray-tracing greatly, so make the iterative ray-tracing segment by segment do its best, and make the method improve its application value.