【作者】 刘宝平；

【导师】 赵彬；

【作者基本信息】 哈尔滨工业大学 ， 信息与通信工程， 2009， 硕士

【摘要】 大带宽步进频率雷达是一种高距离分辨率雷达,由于具有测距精度高、抗杂波能力强、可识别真假目标和反隐身等优点,在精确制导武器中有着广阔的应用前景。而一维距离像可以得到目标散射点个数、长度、径向分布等特征,是提取目标高分辨单元上距离信息的关键。本文主要对步进频率信号体制下一维距离成像方法进行的研究,并将一维距离像成像算法在DSP硬件上实现。首先,介绍步进频率信号波形的定义,并利用模糊函数,详细阐述步进频率波形固有的距离-多普勒耦合特性,为步进频率信号速度补偿提供理论依据。介绍步进频率雷达系统的脉冲综合的原理,并分析和设计了步进频率雷达的性能参数。其次,研究了两类高分辨距离信息提取的方法。一种是基于IFFT目标距离信息提取算法,并进行了仿真和实测数据的验证。另一种是基于小波功率谱分析的距离信息提取算法,从理论上分析了利用小波功率谱进行步进频率雷达回波信号一维成像原理,提出距离匹配去冗余算法,可以在成像过程中直接去冗余,避免了IFFT算法固有的冗余。在此基础上,建立了基于距离匹配小波变换的分布算法,通过两次不同分辨率的功率谱合成实现高距离分辨成像。之后通过仿真实验和实测数据验证,证明本文提出的两种小波方法成像的有效性。然后,分析目标速度对步进频率信号高分辨一维距离像的影响,研究了速度补偿的基本原理,此基础上介绍了多种速度补偿方法,并给出了各种估计算法的估计精度、误差和适用范围。最后,将第三章的距离信息提取的方法在Visual DSP ++的TS101平台下实现。对两种距离估计算法进一步分析和验证两种方法的可行性。经分析、比较选择基于IFFT目标距离信息提取算法完成实际系统距离信息的提取。更多还原

【Abstract】 Stepped frequency signal (SFS) with large bandwidth has great potential applications in accurate control and guide weapons, which has advantages of high range measuring accuracy, anti-clutter-ability, and identification ability of true and false targets. One dimensional range profile include targeted scatter’s number、length、radial distributing, which is very important to extract high resolution range information. In this dissertation, we will focus on processing one dimensional range profile of stepped frequency.Firstly, basic theory of the stepped frequency radar system is summarized and waveformof the stepped frequency radar are analyzed in detail. In the same time, according to the definition of radar waveform’s ambiguity, the characteristics of stepped frequency radar waveform are analyzed which build a foundation for theoretical and experimental studies. Besides, theory of high range resolution profile based on IFFT has been proposed.Secondly, two range profiles method has been studied. one is target extract algorithm based on IFFT. Another is wavelet power spectrum analysis,analyzing theory of SFS echo profile with wavelet power spectrum. a novel technique is proposed. This technique can remove redundancy directly avoiding IFFT immanent redundancy. On this basis, a improved approach for high resolution imaging based on range matched wavelet transform has proposed. The simulation result confirms the effect of the above new technology.Later, for coupling of range and Doppler frequency in stepped frequency signal, it is quite necessary to compensate target motion. According to the relative phase relationship in different pulse period, we research the principle of motion complement and introduce kinds of motion complement method. Then we verify those methods by simulation.Finally, paper implement and verify the method proposed in chapter 3 under TS101 session of Visual DSP ++ environment. By comparison, thesis choose target extract algorithm based on IFFT for real system.更多还原