摘要: |
本文推导了椭圆极化雷达散射矩阵与线极化散射矩阵之间的变换公式,分析计算了目标圆极化散射特性随目标定向角和轴比变化曲线。分析了三面角、二面角、偶极子(线状体)、圆柱体等目标的圆极化雷达散射特性,确认圆极化散射矩阵中各极化分量散射幅值(绝对值)均不随目标定向角变化,偶极子(线状体)目标圆极化散射矩阵各极化分量具有均衡的散射特性;三面角与二面角反射器圆极化散射能量呈现互补关系,三面角交叉极化强,二面角同极化强;圆柱体圆极化雷达散射交叉极化散射能量较大。对公路斜拉桥、舰船、圆柱铁桶等目标圆极化SAR图像进行分析判读,各目标圆极化SAR成像结果与圆极化雷达散射特性分析结果一致,揭示了圆极化SAR固有的目标成像特性。 |
关键词: 圆极化SAR 圆极化散射矩阵 圆极化轴比 目标定向角 |
DOI:DOI:10.3969/j.issn.1672-2337.2020.04.002 |
分类号:TN959.1 |
基金项目: |
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Study on Circularly Polarized SAR Imaging Characteristics of Man-Made Targets |
GE Jialong
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The 38th Research Institute of China Electronics Technology Group Corporation, Hefei 230088, China
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Abstract: |
In this paper the radar scattering matrix transformation between elliptical polarization and linear polarization is derived, and the relationships of circularly polarized scattering characteristics with target’s orientation angle and axial ratio are calculated. The circularly polarized radar scattering characteristics of triangle surface, dihedral surface, dipole and cylinder are analyzed, which confirms that the scattering amplitudes of all polarized components in the circularly polarized scattering matrix are not changed with the target’s orientation angle. All polarized components in the circularly polarized radar scattering matrix of dipole target have uniform scattering characteristics. The circularly polarized scattering energies of triangle and dihedral surface reflectors exhibit complementary relationship, with higher cross-polarization of triangle surface and higher co-polarization of dihedral surface. The cross-polarization scattering energy of circular polarization of cylinder is relatively larger. With the analysis of circularly polarized SAR images of cable-stayed bridge of highway, naval ship, cylindrical barrel and so on, the imaging results agree well with the circularly polarized radar scattering characteristics, and it reveals the residual imaging characteristics of circularly polarized SAR. |
Key words: circularly polarized SAR circularly polarized scattering matrix axial ratio orientation angle |