摘要
As an important step in P-S seismic data processing,the calculation of converted-point position can be obtained by three methods,including strict analytical method,approximate method based on Taylor series expanding and iterative method based on ray tracing.Taking VTI medium with single horizontal interface as example,the steps and formula for calculating converted-point position by secant iterative method were given.Based on isotropic and VTI medium,we compared the computation accuracy of three methods and discussed the influence of anisotropic parameters on calculating converted-point position and travel time.Furthermore limitations of secant iterative method were discussed on strong anisotropic medium.The results is accurate and satisfied with the given computation accuracy since the secant iterative method has no approximation However,when long offset and strong anisotropy are both existing,the cusps phenomenon for reflected SV wave will appear and the method is failed.