半无限大空间中无耗二维电磁目标的微波成像新方法

本文提出利用模拟得到的时域散射信息对埋于半无限大空间中的无耗二维电磁目标进行微波成像的新方法时域变分迭代法(time-domain variational iterative method,TVIM)。这是一种基于电磁体等效原理、变分原理和傅立叶变换的迭代方法,每次迭代各计算正问题和逆问题一次,正问题采用时域有限差分(finite-difference time-domain)方法处理。列举了一些典型的数值反演实例,并与有关文献结果作了比较,考察了TVIM的收敛性能、反演复杂目标能力、抗随机噪声等反演性能,并从理论上简要分析了形成TVIM良好反演性能的原因。

A NOVEL METHOD FOR MICROWAVE IMAGING OF TWO-DIMENSIONAL LOSSLESS ELECTROMAGNETIC TARGET IN HALF SPACE

A novel method, time-domain variational iterative method(TVIM), for microwave imaging of two-dimensional lossless electromagnetic target buried in half space using time-domain scattering data is presented in this paper. It is an iterative method derived using volume equivalence principle, variation principle and Fourier transform. The direct problem is solved by finite-difference time-domain(FDTD) method and the inverse problem is solved iteratively. Some typical results are given to show its performance, such as converging property, ability to invert arbitrary targets, tolerance of random noise, etc. Comparision with the former methods is also done. Those factors which make TVIM performs better are also investigated.