极化波

Polarimetric Synthetic Aperture Radar measures the frequency, magnitude, absolute and relative phase of targets' backscattering signals in imaging scene for any possible combination of transmit and receive antennas. The polarization synthesis technique on one hand has greatly increased the acquired polarization information, on the other hand increased the difficulty of system design and signal processing.

中文摘要极化合成孔径雷达的回波信号可以提供不同收发极化状态组合下成像场景内目标散射波的幅度、绝对和相对相位、频率等信息，极化合成技术的出现使获取的信息量成倍增加，信息量增加的同时系统设计和信号处理的复杂度增加，因此极化合成孔径雷达相关技术的研究成为微波遥感领域的热点。

Second, proceeding with the fact thatthe constructing vector wave functions of conventional circular cylindrical and sphericalvector wave functions are linear independent solutions to the electromagnetic field waveequations in biisotropic medium,spectral impedance boundary conditions are proposed forinfinitely long perfectly conducting circular cylinder and sphere coated with biisotropic media,respectively,which generalize the applicable range of planar structures and are suitable toanalyze the electromagnetic problems involving their counterpart structures.

所用的方法是在Fourier变换谱域中的一阶线性微分方程组理论和矩阵技术，提出了适用于Chiral媒质半空间辐射问题的耦合镜像原理(即镜像电流的振幅和相位是由Chiral媒质中的本征左、右旋圆极化波相互耦合来确定的)和适用于研究平面分层Chiral媒质电磁问题的一般性更高的分析方法。

The new antenna has the advantages of sim ple structure, easy feeding and a wide frequency range, and circular polarized wave. The characteristics are m uch better than a bifilarbackfire helicalantenna, a shortbackfire antenna and a backfire...

它具有结构简单、馈电方便、遮挡小、频带宽、增益高且易于产生圆极化波等优点，性能远优于带相同接地板的螺旋天线、普通短背射天线以及单线背射螺旋作馈源的短背射天线。

In this dissertation, based on the extraction of meaningful polarization information, the polarimetric speckle reduction, polarimetric contrast enhancement, polarimetric classification and ship detection in polarimetric SAR images are systemically studied. During the study, some new concepts and methods are introduced, which are supported by the application to measured Pol-SAR data. The innovations of this dissertation are as follows: 1 A simplified schem is proposed to reduce the complexity of scattering-model-based speckle filtering. 2 Extend the expression of polarimetric correlation coefficient to help distinguishing targets. In addition, introduce the quantized parameters of polarimetric signature so as to show the differentiae in quantity in co-polar power, cross-polar power and shapes of polarization signatures among targets. 3 Define a new parameter of difference degree between targets, which can be used for express the difference between both coherent and distributed scatters.

论文在较系统的研究目标特征量提取方法和特征量所包含的物理意义的基础上，对极化SAR图像降斑、极化对比增强、极化SAR图像分类以及极化SAR图像中海上舰船目标检测等方面进行了研究，并提出了一些新的概念和方法，对实测数据的处理结果表明，这些新的概念和方法对于极化SAR信息处理是有效的，本文的主要创新成果包括以下方面： 1）针对基于预分类的MMSE极化降斑方法实现过程非常复杂的问题，提出了简化方案，并验证了方案的有效性； 2）扩展了极化相关系数的表示方法，这种扩展增强了极化相关系数对目标的区分效果；另外还提出了极化特征图量化参数，可以从量上表征不同目标间相同极化和交叉极化的回波功率差异和极化特征图形状差异； 3）定义了目标间的差异度参数，它不仅可以用于描述相干目标，还可以用于描述分布目标的差别程度。

Five signatures were defined based on polarization synthesis technique, then target optimum polarization could be obtained to partially polarized wave by searching on the signature space.

该方法特别适用于部分极化波的情况，并且它避免了异常繁琐和复杂的数学推导，具有计算简单、操作方便等特点。

All above laid a foundation for the research of polarimetric information processing and application. Then, target optimum polarization and polarimetric synthesis technique were studied. By constraining polarimetric states of transmitting and receiving antennas, co-polarized and cross-polarized signatures were obtained. Because the received wave was partially polarized, completely polarized, completely unpolarized, and total available power signatures were defined based on the power of the return wave.

接着，论文深入研究了目标最佳极化和极化合成技术，通过约束收发天线的极化状态可以得到共极化特征图和交叉极化特征图，由于雷达接收的电磁波通常是部分极化的，根据接收波的平均功率密度可以得到未极化特征图、完全极化特征图和匹配极化特征图，在极化特征图空间中搜索可以很容易地获得目标的最佳极化，这些目标最佳极化可以作为极化目标识别和分类的极化特征。

In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.

这章具体研究了基于三种极化散射特性描述的相应的目标识别方法：①基于极化参数平面描述的目标识别方法，将目标回波极化状态投影到以极化椭圆参数，即椭圆率角ε和倾角τ表征的极化状态平面上，参数随观测频率的变化就形成了图，根据图的变化特点构造了目标的多维极化特征空间，并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构；②基于Poincare极化球面描述的目标识别方法，采用Stokes矢量表征目标回波的极化状态，并将其投影到描述极化状态的Poincare极化球面上，定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息，提取了准方位不变性的目标极化特征，最后设计了目标的识别器结构；③基于频率敏感性描述的目标识别方法，通过在Poincare极化球面上所定义的极化状态距离的概念，研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题，获得了在极化状态距离下的频率分布特性曲线，采用最小二乘估计曲线拟合方法，它既用于极化特征的降维，同时又直接将拟合参数作为目标的分类特征。

Experiment on transmission properties of TE polarized plane wave incidented on frequency selective surfaces.

FSS对TE极化波传输特性的实验研究

We found, for the first time, the negative resistance phenomenon, and interpreted it through the application of the theory of surface plasmon polariton and polarized wave.

报道了对用射频磁控溅射法制备的钛酸锶铅薄膜隧道结进行的 I V特性的测量，发现有负阻现象，并首次用表面等离激元和极化波理论对此作了解

Using a RF antenna,around outside a glass or a quartz tube,which is resonant with the right hand polarized wave propagating in a magnetized plasma,very high density plasma may be produced by Landau damping mechanism.

利用一种环绕于玻璃管或石英管外壁的射频天线与磁化等离子体中的右旋极化波的共振，可以非常有效地通过朗道吸收加热电子，产生高密度等离子体。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。