THz频段粗糙导体圆锥的极化成像特性

太赫兹频段下粗糙导体表面会对电磁散射回波的幅度、相位、极化状态产生影响，为分析这一影响，以导体圆锥为例，研究了不同粗糙参数表面电磁散射在雷达图像中的表现规律。基于谱方法和坐标变换对粗糙圆锥面进行建模，利用高频电磁计算方法获得不同粗糙度导体圆锥样本多角度、多频点、全极化的单站散射场，基于转台模型，利用二重积分法获得目标二维像。从仿真结果可以看出，粗糙与理想光滑导体的圆锥图像存在明显差异，粗糙圆锥图像中能量分布偏离理想光滑情况下的强散射区域；随着粗糙度的增加，图像能量分布愈加均匀；相比于同极化图像，交叉极化图像更具反映目标轮廓信息的潜力。

Characteristics of polarized imaging of a conducting cone with surface roughness at terahertz frequencies

The rough surface of targets can cause complex impact on the amplitude, phase, polarization of the scattered fields at THz frequencies. For weighting and describing surface roughness effects, a Perfect Electric Conductor(PEC) cone is taken as an example to illustrate the characteristics of the scattered fields of rough surface in radar imaging. The model of rough cone surface is obtained based on the spectral method. Multi-angle, multi-frequency, full polarized monostatic scattered fields are obtained by utilizing the high frequency methods of computational electromagnetics. Then the targets images are obtained by using the duplicate integral method according to the rotation model. Obvious differences between rough and ideal smooth cone can be found from the reconstruction images. The simulation results show that as the roughness degree increases, the energy distribution of rough cone images departs from those highlighting regions in smooth cone images; and the cross-polarized images have better potential of describing the target profile comparing to the like-polarized images.