二维有耗介质目标重建的迭代－共轭梯度方法

An Iterative Conjugate Gradient Method for Reconstruction of 2-D Lossy Dielectric Object

本文提出了一种由已知的散射场数据重建二维非均匀有耗目标的复介电常数的迭代算法。连续采用多个方向的ＴＭ平面波照射目标，并分别采集目标区域外的散射场数据。本文利用矩量法．（ＭＯＭ）将积分方程变成矩阵方程，我们以Ｂｏｒｎ近似为初始值，通过多次迭代，实现目标特性的重建。通常，逆问题多是不适定的。为了克服解的不适定性，我们采用共轭梯度法（ＣＧＭ）求解逆问题。最后，通过计算机模拟，给出了一些数值重建结果。

An iterative algorithm is proposed in this paper. To reconstruct the complex pernuttivity of a 2-D inhomogeneous lossy dielectric object from the measured scattered fields ,the object is illuminated successively by TM plane waves of different angles of incidence,and the scattered fileds are measured,for example,at a measurement line.By using the method of moment ,the integral equation can be discretized into matrix form.Starting from Born approximation,the coupled matrix equations are solved iteratively.In general ,inverse scattering problems are mostly illconditioned. In order to overcome the ill-conditioness ,we apply the conjugate gradient method.The computer simulations show the feasibility of the proposed reconstruction scheme.