脉冲多普勒气象雷达信号处理系统研究

【作者】 张华；

【导师】 朱晓华；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2003， 硕士

【摘要】 本论文研究的是采用数字中频接收技术的脉冲多普勒气象雷达信号处理系统，重点研究了中频采样及数字解调技术在脉冲多普勒气象雷达信号处理系统中的应用、正交双通道幅相不平衡对气象回波谱估计的影响、地杂波滤波算法，以及脉冲多普勒气象雷达信号处理系统的具体工程实现。 首先简要介绍了气象雷达的雷达方程、气象雷达探测气象目标的基本原理、气象目标回波的时域频域特性和气象回波信号的模拟方法。并在此基础上介绍了气象雷达信号处理系统的基本构成与各部分的主要功能，主要包括气象回波中频接收、杂波抑制、距离订正、平滑处理、解模糊和谱矩估计等。 其次，本文研究了中频采样及数字解调技术在气象雷达中的应用。首先对回波正交双通道幅相不平衡对气象回波谱估计的影响进行了详细的理论推导和计算机仿真。理论分析与仿真结果均表明了正交双通道幅相不平衡对气象回波谱矩估计具有明显的影响。由于采用中频采样和数字解调技术能有效地提高正交解调两路的幅相一致性，本文将中频采样及数字解调技术应用到脉冲多普勒气象雷达信号处理系统中，并结合气象信号的特点选择了适合工程实现的中频采样及数字解调算法。 本文还结合气象雷达地杂波的特点详细研究了各种滤除地杂波滤波算法，在对各种滤波算法进行分析和折中考虑之后，选择地杂波频域滤波算法应用于本信号处理系统。 最后，本文提出了脉冲多普勒气象雷达信号处理系统的一种具体软硬件实现方案。更多还原

【Abstract】 This thesis discusses the Pulse Doppler (PD) weather radar signal processing system including digital intermediate frequency (IF) receiver, especially on the application of IF sampling and digital demodulation technique in PD weather radar signal processing system, the influence of amplitude and phase unbalances of in-phase and quadrature channels on weather radar echo spectrum estimation,ground clutters elimination algorithms and a typical engineering realization scheme of PD weather radar signal processing system.Firstly, we introduce the Radar equation of weather radar, the basic principles of detection weather targets, the time and frequency domain properties of weather radar echo and its simulation methods. Then, we introduce the basic structure of PD weather radar signal processing system and their function of each subsystem, mainly including intermediate frequency receiver, clutter elimination, range correcting and smoothness, ambiguity resolution and spectrum estimation.Secondly, we discuss the application of IF sampling and digital demodulation technique in PD weather radar signal processing system. First of all, the mathematical development and extensive computer simulation are used to analyze the influence of amplitude and phase unbalances of in-phase and quadrature channels on weather radar echo spectrum estimation. The theoretic analysis and computer simulation results reveal that this influence can’t be ignored. Because the IF sampling and digital demodulation technique can improve amplitude and phase unbalances of in-phase and quadrature channels, we apply it in the PD weather radar signal processing system and select several digital demodulation algorithms, which are easier to implement, for this system.Thirdly, we study several ground clutters elimination algorithms combining the properties of ground clutters and we get the conclusion that the frequency domain algorithm has better performance through extensive analysis and comparison.Finally we proposed a typical PD weather radar digital signal processing system realization project including the software and hardware implementation.更多还原