Using orthogonal-octahedron finite-difference (FD) stencils, even-order accuracy for temporal and spatial derivatives can be reached for 3D acoustic wave equation modelling. However, the required length of FD operator is still long for high accuracy modelling. To tackle this issue, we have developed an optimization method using a combination of Taylor-series expansion plus Remez exchange methods. The Taylor-series expansion for the octahedron-shaped operator ensures high temporal accuracy and the Remez exchange for axial operator further improves the spatial accuracy. The comparison between our method, exisiting 3D temporal high order method and space domain least-square opimization method validates the efficiency and accuracy superiority of the new method.

使用正交八面体有限差分（FD）模具，可以实现3D声波方程建模的时间和空间导数的偶数精度。但是，FD运算符所需的长度对于高精度建模仍然很长。为了解决这个问题，我们开发了一种优化方法，该方法结合了泰勒级数展开式和Remez交换方法。八面体形算子的泰勒级数展开可确保较高的时间精度，而轴向算子的Remez交换可进一步提高空间精度。通过将现有3D时态高阶方法与空间域最小二乘优化方法进行比较，验证了该方法的效率和准确性。