雷达旁瓣相消和杂波抑制的研究与实现

发布时间：2018-05-15 00:27

本文选题：旁瓣相消 + 动目标显示　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：雷达接收到的回波信息中通常包含目标、杂波、干扰和接收机噪声,而且杂波和干扰信号通常要比目标信号强很多,这会严重影响雷达的正常工作。雷达信号处理的重要内容就是要从复杂的回波信号中提取出感兴趣的目标信号。旁瓣相消是雷达抗旁瓣有源干扰既经济又有效的技术。开环自适应旁瓣相消是基于最小均方误差准则计算最优权系数,之后将权系数应用于旁瓣相消系统中,它可以根据输入信号的变化自动地修正权系数。理论分析中,自适应旁瓣相消技术可以很好地抗有源旁瓣干扰,但是实际中往往出现相消效果不理想的情况。本文对影响自适应旁瓣相消性能的因素进行了较为详细地分析说明,这也是在工程实践中需要注意的问题。动目标显示技术和动目标检测技术是雷达进行杂波抑制的主要技术,它们是基于杂波信号与目标回波信号在频谱上的差异,利用滤波器将杂波消除掉,进而提取出目标信息。常规动目标显示滤波器频率特性是周期性的,往往会使得盲速目标也被消除,可以利用参差重复频率技术将第一盲速推到较远的多普勒频率处,以满足工程实践的要求。对于气象、箔条等动杂波采用自适应动目标显示实现对动杂波的抑制。自适应动目标显示的重要内容是对动杂波谱中心的估计,本文采用了质心法较为准确地估计动杂波谱中心并将其应有于工程实践中,实践效果验证了该方法的正确性。动目标显示技术的核心内容是杂波抑制滤波器的优化设计,本文给出了优化设计滤波器的常用方法。工程实现部分,本文阐述了基于数据流驱动的雷达信号处理系统运行的基本原理。将数据流思想应用于雷达信号处理系统中,整个雷达系统的工作完全靠数据流驱动而不再有统一的时序控制,这也是雷达信号处理系统发展的一个方向。对旁瓣相消和杂波抑制的硬件平台进行了描述,对旁瓣相消和杂波抑制的数字信号处理器(Digital Signal Processor,DSP)实现进行了详细流程说明。旁瓣相消部分,详细说明DSP计算旁瓣相消权系数的流程并给出实测数据分析的结果。杂波抑制部分,对杂波抑制DSP程序中的主要功能模块加以说明,详细说明了自适应动目标显示技术的工程实现并给出了雷达终端显示的实测效果图。对工程中遇到的主要问题及其解决技巧进行详细阐述,包括自适应延时控制和连续方位选大问题。
[Abstract]:Radar echo information usually contains target clutter interference and receiver noise and the clutter and jamming signal is usually much stronger than the target signal which will seriously affect the normal operation of radar. The important content of radar signal processing is to extract the target signal of interest from the complex echo signal. Sidelobe cancellation is an economical and effective technique for radar to resist sidelobe active jamming. The open-loop adaptive sidelobe cancellation is based on the least mean square error criterion to calculate the optimal weight coefficient. Then the weight coefficient is applied to the sidelobe cancellation system. It can automatically correct the weight coefficient according to the change of input signal. In theoretical analysis, adaptive sidelobe cancellation technology can resist the active sidelobe interference well, but in practice, the cancellation effect is often not satisfactory. In this paper, the factors affecting the performance of adaptive sidelobe cancellation are analyzed in detail, which is also a problem needing attention in engineering practice. Moving target display technology and moving target detection technology are the main technologies of radar clutter suppression. They are based on the difference between clutter signal and target echo signal in the spectrum. The clutter is eliminated by filter and then the target information is extracted. Conventional moving targets show that the frequency characteristics of the filter are periodic, which often eliminates the blind velocity target. The staggered repetition rate technique can be used to push the first blind velocity to the far Doppler frequency to meet the requirements of engineering practice. For weather, chaff iso-dynamic clutter is suppressed by adaptive moving target display. The important content of adaptive moving target display is to estimate the center of moving clutter spectrum. In this paper, the centroid method is used to estimate the center of moving clutter spectrum accurately and it should be applied in engineering practice. The practical results show that the method is correct. The key content of moving target display technology is the optimal design of clutter suppression filter. In the part of engineering realization, the basic principle of radar signal processing system based on data stream driving is described in this paper. The idea of data flow is applied to the radar signal processing system. The work of the whole radar system is driven by the data flow and there is no unified time series control, which is also a developing direction of the radar signal processing system. The hardware platform of sidelobe cancellation and clutter suppression is described, and the implementation of digital signal processor digital Signal processor for sidelobe cancellation and clutter suppression is described in detail. In the part of sidelobe cancellation, the flow of calculating sidelobe cancellation coefficient by DSP is explained in detail, and the analysis results of measured data are given. In the clutter suppression part, the main function modules in the clutter suppression DSP program are explained, the engineering realization of the adaptive moving target display technology is described in detail, and the actual effect diagram of the radar terminal display is given. The main problems encountered in engineering and their solving techniques are described in detail, including adaptive delay control and continuous azimuth selection.
【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】：2014
【分类号】：TN957.5

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