【摘要】 傅里叶有限差分(FFD)法兼有相位屏法和隐式有限差分法二者的优势,能够处理复杂地质构造中的波传播问题,但在三维情形下,算子的双向分裂会引起明显的方位各向异性误差.本文用Fourier变换计算双向分裂过程中的高阶交叉项,消除了方位各向异性误差.该方法充分利用了FFD法在双域实现的算法结构,明显减少了由于引入误差校正所带来的计算量.将该方法应用于修改后的三维French模型的地震正演问题,并将得到的叠后记录、单炮记录同全波有限差分法的模拟结果进行对比,结果证实了该方法对一次反射波具有较高的模拟精度,在内存需求和计算效率方面则具有更大的优势.更多还原

【Abstract】 Fourier finite-difference(FFD) operator has both of the advantages of Fourier and finite-difference methods,it can handle the wave propagations in complex media with large velocity contrasts and wide propagation angles.In 3-D case,however,two-way splitting may cause artificial azimuthal anisotropy.In this paper,we handle the remnants of the conventional two-way splitting technique by Fourier transforms,and the azimuthal anisotropy is removed.Based on the dual-domain scheme of the FFD method,the proposed algorithm significantly reduces computational cost caused by error correction.Compared with the finite-difference method by the zero-offset records and shot profiles based on 3-D modified French model,the proposed method can properly model the primary reflected waves and is much more attractive in both computational cost and storage demand.更多还原