基于时域有限元的近场单站导体柱微波成像

Near-field monostatic microwave imaging of conductor cylinder based on time-domain finite element

介绍了一种在自由空间中对导体柱近场单站电磁成像的时域数值方法。提出以不均匀分布的点——离散点描述法,来代替通常采用的有限项三角级数逼近的形状函数来描述散射体。在正过程中采用时域有限元法获得其近区散射场,逆过程则通过遗传算法来寻找最优解。以不均匀分布于导体表面点的矢径的模作为优化变量。以在整个迭代过程中,目标散射场和计算散射场的误差总和与目标散射场场值绝对值之和的比值作为目标函数,使目标函数达到最小值来获得导体柱在自由空间中的电磁成像。

A time-domain numerical method to achieve reconstruction of conductor cylinders was considered in this paper. The obstacle is characterized by the uneven distribution points instead of the usual shape function. The electric field is solved by Time-Domain Finite Element Method （TD-FEM）, and Genetic Algorithm （GA） is adopted as the optimization method. Norm of the uneven distribution pointrs radius vector is set as the independent variables for the fitness function. The objective function is the ratio of the total error between the scattering electric field of the obstacle and computed scattering electric field to the sum of norm of the scattering electric field of the obstacle. Imaging results is achieved by minimize the objective function through the genetic algorithm.