矩形旋转交错网格PML边界条件的研究与实现

摘要

现有的频率域波全形反演多是默认基于正方形旋转交错网格,而基于矩形旋转交错网格的全波形反演有更大的灵活性,能更好地适应实际地下介质结构,有更好的内存使用率和计算效率.为了解决原始的基于正方形网格的PML(完全匹配层)吸收边界形式不再适用的问题,文中将通过声波方程完全匹配层吸收边界的经典方法,构建并推导出PML吸收边界条件在矩形旋转交错网格中的具体形式,通过Marmousi模型正演和反演实验,得出本文所构建的PML边界获得良好的吸收效果,对反演结果有很好的改善.%The present Frequency-domain full waveform inversion (FWI) is mostly default to a rotated square-grid,but the FWI based on rotated rectangular-grid is more flexible,and can better adapt to the actual structure of underground media,and have greater adventage in memory utilization and computational efficiency.To overcome the problem that the original square-grid PML (Perfectly Latched Layer) absorbing boundary conditions no longer apply,the paper give the new form of PML absorbing boundary conditions based on rotated rectangular-grid through the classic building strategy .Using the forward modeling and inversion experiment with Marmousi model ,we show that the proposed PML boundary in this article can obtain satisfactory absorbing effect ,and improve the inversion result.