宽带全极化雷达试验系统设计

发布时间：2018-06-12 23:35

本文选题：宽带全极化 + 极化散射矩阵　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：日益复杂的电磁环境要求雷达系统在具备较远的探测距离与较高的探测精度的基础上,还需要具有较强的智能化信息处理能力,同时希望从回波信息中提取出更多目标物理特性信息,以实现对雷达目标更为精确的检测与识别。全极化测量与高分辨成像技术均为现代雷达技术极为重要的研究方向,它们分别从不同角度描述了目标特性,二者相结合具有极为广阔的应用前景。利用回波信号中的极化信息可以获得目标的结构、表面粗糙度与材质等物理特性,即目标的形状及特性与其极化信息有着密切的联系,故极化信息能全面的描述目标的物理特性;另一方面,宽带高分辨成像技术精细地描述了目标的细微特征,极大地提高了其极化模型的准确性。本文首先介绍了宽带全极化雷达基本理论,主要包括极化散射矩阵、极化测量体制及基于步进频率信号的一维高分辨成像算法,通过仿真实验给出了全极化四通道一维高分辨距离像仿真结果,直观形象地说明了极化散射矩阵和一维高分辨距离像之间的关系。其次详细阐述了宽带全极化雷达试验系统的结构设计和参数设计,具体包括雷达接收机与雷达发射机的结构设计,雷达系统参数如发射功率、接收机噪声系数、接收机灵敏度、动态范围和增益等的确定,并给出了收发系统指标分配方案。经过多次对设计方案的修改和调整,理论计算结果满足了所要求的雷达系统总体指标,为后续的雷达系统的仿真与验证工作提供理论基础。在此基础上利用Matlab/Simulink对宽带全极化雷达试验系统进行仿真验证,首先进行了雷达系统单模块的设计,主要包括发射波形设计、目标回波设计、混频器设计、放大器设计等;其次利用已设计的模块搭建出双通道雷达接收仿真系统,通过两个脉冲重复周期仿真获得全极化回波数据,并在关键模块后利用示波器观测其波形,以验证输出结果的正确性。最后介绍了数据处理子系统的相关算法,如利用P_ESPRIT算法进行目标极化散射矩阵估计以及利用Pauli基分解完成极化校准,并分别通过Simulink理论仿真数据和宽带全极化实测数据对相关算法进行了验证和分析,实验结果表明了本试验系统所采用的数据处理算法的有效性。
[Abstract]:The increasingly complex electromagnetic environment requires the radar system to have a relatively long detection range and high detection accuracy, but also to have a strong intelligent information processing ability. At the same time, we hope to extract more target physical characteristic information from echo information, so as to achieve more accurate detection and recognition of radar target. Full polarization measurement and high resolution imaging are the most important research directions of modern radar technology. They describe the target characteristics from different angles, and the combination of them has a very broad application prospect. The structure of the target can be obtained by using the polarization information in the echo signal, and the physical properties such as the surface roughness and the material, that is, the shape and characteristics of the target are closely related to the polarization information of the target. Therefore, polarization information can describe the physical characteristics of the target comprehensively. On the other hand, wideband high-resolution imaging technology describes the fine characteristics of the target, which greatly improves the accuracy of the polarization model. In this paper, the basic theory of wideband fully polarized radar is introduced, including polarization scattering matrix, polarization measurement system and one dimensional high resolution imaging algorithm based on step frequency signal. The simulation results of one-dimensional high-resolution range profile with four-channel polarization are given, and the relationship between polarization scattering matrix and one-dimensional high-resolution range profile is illustrated intuitively. Secondly, the structure design and parameter design of wide-band fully polarized radar test system are described in detail, including the structure design of radar receiver and radar transmitter, the radar system parameters such as transmitting power, receiver noise coefficient, receiver sensitivity, etc. The dynamic range and gain are determined, and the index allocation scheme of the transceiver system is given. After several modifications and adjustments to the design scheme, the theoretical calculation results meet the requirements of the overall radar system index, and provide a theoretical basis for the subsequent simulation and verification of the radar system. On this basis, we use Matlab / Simulink to simulate the wide-band full-polarization radar test system. First, we design the single module of radar system, including the design of transmitting waveform, the design of target echo, the design of mixer, the design of amplifier and so on. Secondly, a two-channel radar receiving simulation system is built by using the designed module. The full polarization echo data are obtained by the simulation of two pulse repetition periods. After the key module, the waveforms are observed by oscilloscope to verify the correctness of the output results. Finally, the algorithms of data processing subsystem are introduced, such as the estimation of polarimetric scattering matrix using Pesprit algorithm and the polarimetric calibration by Pauli basis decomposition. The simulation data of Simulink theory and the measured data of wide-band full polarization are used to verify and analyze the algorithm. The experimental results show the validity of the data processing algorithm used in the experimental system.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN95

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