有耗媒质中目标的无相位衍射层析成像方法

Diffraction Tomography in Lossy Background with Phaseless Data

提出一种新的应用于有耗媒质的无相位衍射层析成像方法:只需测量总场的幅度,不需相位信息,实现损耗媒质中二维弱散射目标重建.该方法首先基于测量到的场幅值确定出目标函数在复二维空间中的"伪Fourier谱",将"伪Fourier谱"构造关于目标函数的Fourier级数展开系数的方程组,对此病态方程组作正则化处理求解目标函数的Fourier级数展开系数,即可反演出目标.论文的仿真结果表明,该无相位成像方法能够很好地重建损耗背景中目标的位置、尺寸及电特性参数,证明了无相位衍射层析成像方法在有耗媒质中应用的可行性和有效性.

A novel method related to diffraction tomography is presented for imaging two-dimensional weak-scattering objects embedded in a lossy background with phaseless data.The proposed method requires only intensity measurements.Based on the information of the total field magnitudes the pseudo Fourier transformation of the object function can be determined,which is distributed along a fixed arc in the complex space.After expanding the object function by Fourier series the pseudo Fourier spectrum can be represented by the Fourier coefficients,which can be written in a form of system of equations.By means of regularization the ill-posed matrix can be solved and the object function is reconstructed.Numerical simulation results presented have proven the validity of the proposed method.Since this reconstruction algorithm needs only intensity information to rebuild the geometric and electromagnetic properties of objects embedded in a lossy background,it circumvents the difficulty of direct phase measurement.