二维横向各向同性介质的伪谱法正演模拟

Pseudo-spectral forward modeling in 2-D transversally isotropic medium

本文用伪谱法进行二维横向各向同性介质的正演模拟。文中给出了计算的稳定性条件并作了证明，对边界条件也进行了有效的处理。吸收边界条件采用Takashi提出的反周期扩展法或是与衰减型吸收边界条件相结合的方法。数值模拟的共炮点记录表明，该方法具有精度高、波形特征清晰、边界吸收明显的优点，完全可以推广到其它各向异性模型的波场正演模拟中。它为各向异性波形反演、偏移成像提供了一种有效的正演方法。

Forward modeling in 2-D transversally isotropic medium is achieved by usingpseudo spectrum method. Stable computation condition is given and demonstrated,and boundary condition is processed effectively. Absorbing boundary condition issolved by taking the anti-periodic extension method (Takashi) or its combinationwith attenuate absorbing boundary condition. Numerical-modeled common-shotseismograms show that this method brings some advantages such as desirable accuracy, clear waveform and obvious boundary absorption, thus also favouring wavefield forward computation using other anisotropic model. It is an effective forwardmethod for waveform inversion, data migration and image in anisotropic media.