Three Dimensional Acoustic Contrast Source Inversion Method

In this paper, we extend the improved acoustic multiplicative regularized contrast source inversion (MR-CSI) method to three dimensions. There are mainly three problems that need to be solved. Firstly, due to the increase in unknowns, the ill-posedness of the problem is more severe, and it would be more complicated in reconstructing object of interest. Secondly, the field distribution changes from two dimensions to three dimensions, that is, the field would also propagate along vertical direction, so the problem is more nonlinear. Besides, the investigated domain also expands from two to three dimensions, so the computational cost and storage increases greatly. For the first two problems, our solution is to choose a stronger regularization to reduce the uncertainty of the solution. And we also use FFT acceleration to reduce the computational time and storage space. Numerical results show that the three-dimensional improved acoustic MR-CSI method can well reconstruct acoustic parameters of the target.