杂波情况下雷达天线的最优极化

本文建立了求相对最优极化的一种新的数学模型，并提出了两种解法．一种是根据奇异值分解理论和求极值的方法，书问题转化成解一个二元高次方程组；另一种方法是：利用接收功率的一种表达式，书问题转化成一个双线性问题，再用一种交替迭代的数值方法予以求解．计算结果表明：这两种方法求得的最优极化是完全相同的     

涂覆型圆柱的散射矩阵及极化分析

利用物理光学法及平面板块元法,对涂覆型圆柱的顶面和侧面的散射矩阵进行了推导和计算;利用一致性几何绕射理论分析了曲棱的一阶绕射场的散射矩阵;指出文献中的错误,然后通过散射矩阵分析目标散射场的极化特性参数和最优极化,给出了具体算例。     

雷达极化理论中常见极化散射矩阵特性分析

介绍了雷达极化理论中常见的辛克菜散射矩阵，米勒散射矩阵，格雷伍斯功率散射矩阵等极化散射矩阵，并对其特性进行了较详尽的分析。导出了上述各种极化散射矩阵间的相互变换关系式，从而为其在雷达目标检测和识别领域中的应用提供了相应的理论依据。     

有限长圆柱后向散射场的极化特性

应用物理光学和一致性几何绕射理论给出了有限长导体圆柱在完全平面极化电磁波照射下后向散射场的极化散射矩阵表示式，分析了圆柱体后向散射场的极化特性。     

有限导电圆柱散射极化特性分析

利用极化理论和高频方法对有限长理想导电圆柱后向散射场的极化特性进行分析和计算，给出了目标极化散射矩阵，不同方向角，不同极化射波的雷达散射截面及其数值结果，理论分析和数值结果对雷达目标极化检测与识别、隐身与反隐身等信息传输技术有参考价值。     

斜投影三维极化滤波

为解决传统三维极化滤波造成的高频地波雷达目标信号极化损失和相位失真,提出一种基于斜投影的三维极化滤波方法,利用目标和干扰的矢量信号分别构建信号和干扰矢量子空间,使用斜投影算子作为滤波矢量进行三维极化滤波.与传统的三维极化滤波相比,基于斜投影的三维极化滤波方法在完全滤除干扰信号的同时对目标信号的幅度和相位不产生影响,有效提高了滤波器输出信号和干扰噪声功率之比(SINR)及信号相参性.仿真结果证实了该算法可以有效抑制高频地波雷达中的干扰信号.     

基于极化矢量相似系数的极化Lee滤波改进算法

在相干斑抑制过程中,极化Lee滤波器的纹理保持性受到同性介质选取准确性的较大影响。通过引入极化矢量相似系数作为全极化SAR复图像数据的同性介质选择准则,给出了一种改进的极化SAR相干斑Lee滤波算法。实测数据的仿真实验表明,与极化Lee滤波器相比,改进算法具有较好的相干斑抑制效果,提高了滤波结果的纹理保持能力。     

交替极化敏感阵列投影滤波性能分析

针对基于极化敏感阵列的传统投影滤波中阵列结构设备量大、对极化参数要求高以及无法确定滤波损失量等问题,以交替极化敏感阵列为信号接收模型,在设备量减半的情况下也可有效滤波,解决了极化敏感阵列结构性价比较低的问题.同时对传统投影滤波算法做了改进,新的斜投影滤波在期望信号极化参数未知的情况下推导出斜投影滤波算子,再利用该算子提取干扰信号,然后利用对消原理获取纯净的期望信号,有效地解决了传统斜投影滤波对极化参数要求较高的问题;而新的正交投影滤波通过构造正交投影滤波算子,可以确定滤波损失量的变化情况.分析结果表明:改进的斜投影滤波,可以有效地滤除干扰信号,极大地拓展斜投影滤波的限制条件;改进的正交投影滤波可以获得滤波损失量,具有重大的理论意义.     

杂波环境下基于粒子滤波的雷达微弱目标TBD算法

针对杂波环境下的雷达微弱目标检测前跟踪问题,提出了 Weibull杂波分布下PF-TBD算法。该算法采用 Weibull杂波分布的量测模型,并基于粒子滤波算法,推导出似然函数和粒子权重。仿真结果表明,Weibull 杂波环境下 PF-TBD算法稳定性良好。     

极化滤波技术的有效性研究

极化滤波技术在高频雷达抗天波干扰等领域有着广泛的应用，结合实际雷达测得的目标回波和干扰回波矢量数据，对极化滤波误差产生的原因、减小误差的方法以及利用极化滤波方法提高信干比的有效性进行了详细分析，结果表明，极化滤波的效果取决于目标、干扰信号的极化状态，在实际应用中为提高极化滤波器的滤波效果，增强对干扰信号的抑制能力，要选择最佳极化状态，同时尽可能减小对干扰极化状态的估计误差。     

Target polarization recognition under rain and snow cluster

This paper derives the polarization scattering matrix of both the warship target and the interferential chaff conditioned on the exit of rain and snow cluster, and furthermore, proposes a method to recognize the chaff and warship by analyzing their corresponding polarization information. This method mainly aims to the radar, which can receive both the left and right circularly polarized wave to catch the full polarization information of echoes, and then acquires more accurate polarization characteristics of the target and chaff after getting rid of the impacts of rain and snow cluster from the polarization scattering power matrix of echoes. In order to further improve the recognition probability, the non-linear polarization transformation is introduced to make the separation of target and chaff more realizable. It indicates that the resulting performance is incredible for the traditional recognition in time and frequency domain.     

矢量天线空频极化域联合滤波新方法

研究了单矢量天线的滤波问题，为了充分利用信号和干扰的空域、频域和极化域信息，提出了LCMV准则下的空频极化域联合滤波新方法，当信号和干扰在任何一个域中有差别时，该滤波方法都能更好地抑制干扰，提高输出信干噪比，通过比较可知空频极化域联合滤波方法比空域极化域联合滤波方法的性能要好。     

Floating small target detection in the sea clutter via block-whitened clutter suppression

It is always a difficult task for the marine surface surveillance radar to detect the floating small target embedded in the sea clutter. Considering the non-uniform and non-stationary nature of sea clutter, the block-whitening strategy is used to suppress the clutter. By analyzing the differences between the energy distributions of the clutter-only returns and those of the returns with the target in the time-frequency (TF) plane, a TF feature is extracted via the TF-ridge-aided Hough transform. A detector using the TF feature is proposed. Experimental results for the IPIX radar datasets show that the proposed detector attains a better detection performance than the fractal-based detector in a relatively short observation time.     

Practical calibration method for instantaneous polarization radar systems utilizing a metal sphere

A practical calibration method is proposed for instantaneous polarization radar systems.The method only needs one measurement by using a metal sphere.The distortions of system and the actual polarization scattering matrix（PSM）of target can be obtained.First,an instantaneous polarization radar system is presented.The system can obtain PSM by a single pulse echo.The dual-polarization antenna can transmit and receive two orthogonal polarization waves.The multilayer micro-strip patch antenna is adopted for this kind of radar system.Second,based on the multi-port network theory,the operation and system errors of instantaneous polarization radar system are analyzed.By making assumption on the cross-talk factors of antenna,distortion matrices of R and Tare derived.Finally,the calibration method based on instantaneous polarization measurement is introduced.Simulation results show the performance of this calibration method.The values of calibrated PSM are in agreement with the actual ones after calibration.     

奇异值方法在极化滤波中的应用

多波多分量技术不断发展,对波场分离的精度要求也日益提高,极化滤波是分离波场的有效手段。本文通过奇异值方法对原有特征值构建的极化滤波器进行了改进,得到了效果更好的极化滤波器。     

Super-resolution imaging method for the SAR target in a strong clutter scene

This paper proposes a super-resolution imaging method to solve the problem of extracting targets and enhancing resolution under a strong clutter in the SAR image. Based on singal correlation, an adaptive clutter threshold is proposed to extract strong scatterers of targets. Then weak scatterers of targets are extracted by the gradient descent method. Finally, target resolution is enhanced to realize super-resolution imaging by the simplified regularization method. Real-measured data of reflectors and the stationary vehicle validate the effectiveness of the proposed method.     

浅层埋地介质目标散射特性及介质探雷器的研究

本文对于浅层掩埋或半埋半露的介质目标的散射特性作了理论上的分析。用平衡振子天线系统用为探雷器的探头，对于探测高度和掩埋深度都很小的情况下，近区场模型进行数值计算，探讨当探雷器在目标上方扫描时所引起的场的扰动而得到信号输出的检测原理。计算的结果与实便的结果有相当好的一致性。