基于后向散射场数据的舰船目标高分辨雷达成像技术

Abstract

为使高分辨雷达图像更精确反映舰船目标的结构、形状特点，研究了基于后向散射场数据的舰船目标高分辨雷达成像技术。建立了舰船目标三维模型，采用三角面元对模型进行剖分，利用物理光学法计算面元的镜面反射，应用等效电流法计算模型棱边部分绕射，依据机载雷达聚束式合成孔径(SAR)成像原理，得到舰船目标在不同姿态角和频率采样点的后向散射场。通过数据变换得到目标的一维距离像以及SAR图像，在此基础上研究了入射频率、方位角和极化方式对舰船目标探测的影响。仿真结果表明，该技术应用后向散射场数据得到的雷达SAR图像能反应出舰船的基本特征，可应用于舰船目标自动识别。 In order to reflect the characteristics of ship’s structure and shape by using radar High Resolution Range Profile (HRRP), the radar imaging technology based on back scattering data is researched in this paper. The three dimensional model of the vessel is established and parted based on triangular elements. The specular reflection and edges’ diffraction of ship model are calculated by using the Physic Optic method (PO) and The Method of Equivalent Currents (MEC) respectively. According to the principle of spotlight imaging, the back scattering on different angles and frequency are calculated. The one-dimensional range profile and synthetic aperture radar imaging are obtained by data transformation. The influence of frequency, angle and polarization on detection of ship target is analyzed. The result shows that the SAR based on back scattering data can reflect the basic characteristics of the ship which is useful for ship recognition.