基于变形玻恩迭代法的多重网格反演方法

将多重网格技术与变形玻恩迭代法相结合,对轴对称二维非均匀介质分布进行了反演。在反演过程中首先利用变形玻恩迭代方法近似地反演出目标函数的平均值,然后逐级细分目标区域的离散网格。通过计算实例表明,该方法具有稳定性好的特点,不但可以极大地降低反演过程的计算量,而且能更精确地反演高对比度的散射目标。

Multi-Grid Inversion Method Based on Distorted Born Iterative Method

The profile of a two-dimensional axi-symmetric inhomogeneous medium is reconstructed by using the distorted Born iterative method and multi-grid technique. In the previous inversion procedure, we consider the whole objective area as one grid, and the mean value of the objective function is obtained approximately by the distorted Born iterative method; then the size of the discretization grid inside object gradually is reduced, the results reconstructed in the last level grid is used as new background medium and the profile reconstruction of the objects is solved continuously by the distorted Born iterative method. The numerical examples show that the new method has the robust feature, the computational time of the inversion procedure is reduced vastly and more accurate inversion results of the higher-contrast scattering objects can be obtained.