横向各向同性介质中的相移法偏移

Phase shift migration in transversely isotropic medium

本文在非垂直对称轴横向各向同性（TI）介质情况下，引用描述平面声波传播的克里斯托弗尔（Christoffel）方程，推导出TI介质中SH波、qP波和qSV波的频散关系式；然后根据单程标量波动方程相移法偏移的原理，讨论了这三种波偏移向下延拓算子的解析表达式以及在TI介质中相移法偏移的实现方法。理论脉冲响应的计算证明了该方法的正确性。

In the case of transversely isotropic medium without vertical axial symmetry,the frequency dispersion formulae of SH,qP,and qSV waves in transversely isotrop-ic medium are derived from Christoffel equation,which describes the propagation of plane acoustic wave. According to principle of phase shift migration using single-way scalar equation,we then discuss both analytic expressions of d0wn-ward con-tinuation operators in these wave migrations and the method for achieving phaseshift migrati0n in transversely isotropic medium. Computation result of theoreticalpulse responses proves the method right.