【作者】 闫冯军；

【导师】 夏传浩；

【作者基本信息】 合肥工业大学 ， 信号与信息处理， 2006， 硕士

【摘要】 宽带雷达具有高的距离分辨率(High Range Resolution),目标被其照射时呈现多散射点模型,其回波是雷达发射信号和目标冲击响应的卷积,它在信号形式上和发射信号差别很大。和传统的低分辨雷达相比,宽带高分辨雷达表现出许多新的特点和优越性,常规低分辨雷达回波的检测方法已经不再适合于高分辨雷达。由于信号带宽的增加,一个目标占据了更多的信号处理单元,如何合理利用目标占据多信号单元的这一特点来提高检测性能是当前雷达信号处理所关心的问题。同时,高分辨情况下目标的运动会造成多周期回波包络的跨单元走动,目标距离走动带来了整个检测性能的下降。当目标的先验参数未知时,如何进行多周期包络补偿是宽带雷达信号检测需要解决的主要问题之一。本文以线性调频(LFM)信号为例,合理地建立了宽带雷达体制下的目标多散射点模型和高分辨回波模型,对宽带雷达回波的多周期包络补偿相参积累方法进行了研究,最后提出了一种基于横向距离单元合成处理的包络补偿相参积累新方法,理论和仿真实验验证了该方法的可行性和有效性。该方法较好地克服了运动目标的包络走动的影响,它提高了信噪比、改善了检测性能,具有很大的实际意义。更多还原

【Abstract】 Wide-band radar has high range resolution, and target takes on multi-scattering model when illuminated by it. Its echo is the convolution of radar transmitting signal and target impulse response,and echo waveform is very different from transmitting signal waveform.Comparing with traditional low range resolution radar, wide-band radar represents much new characteristic and advantage, so methods of traditional LRR radar detection are not suitable for HRR radar. Because of band’s increasement, one target may takes up more signal cells, and how to utilize this characteristic to enhance detection performance has become an important problem in radar signal processing field. In HRR conditions, target’s migration can cause envelop migration of echo within multicycle accumulation time and bring the drop of entire detection performance. When transcendental parameters are unknown, how to compensate envelop migration is one of primary problems on wide-band radar detection. Based on linear frequency modulation signal, this paper rationally establishes HRR target multi-scattering model and echo model, and studies some phase-coherent accumulation methods for multicycle echo envelop compensation, finally brings forward a new phase-coherent accumulation method for envelop compensation based on transverse range cells’ compound processing. Both theory and simulation experiment validate its feasibility and validity. This arithmetic preferably overcomes the influence brought by envelop migration of moving targets, enhances signal noise ratio, improves the detection performance and has better practical meaning.更多还原