双偏振天气雷达时域和频域回波信号仿真方法对比研究

Comparison between Frequency Domain Echo Simulation Method and Time Domain Echo Simulation Method of Dual Polarization Weather Radar

相比雷达实验,通过仿真产生双偏振天气雷达回波信号,分析雷达系统性能提高、扫描策略优化、处理算法改进等对雷达观测数据的影响,是一种成本低、见效快、分析全面的有效方法。介绍时域和频域两种不同的双偏振天气雷达回波仿真方法,其中频域仿真方法是以高斯型功率谱为基础,构建天气雷达回波频谱特征,然后通过引入双通道幅度、相位差异及相关性构建水平和垂直两个通道的偏振回波信号。时域仿真方法则是以脉冲信号之间自相关函数为基础,构建回波信号自相关矩阵,然后通过Cholesky分解得到水平通道I/Q回波信号,并采用类似频域建模方法中的双通道幅度、相位差异及相关系数生成垂直通道的回波信号。仿真结果表明,两种方法都能实现双偏振天气雷达回波的仿真。

Compared with radar test,it is an effective method with low cost,quick effect,and comprehensive analysis to generate dual-polarization weather radar echo signal through simulation and analyze the influence of radar system per-formance improvement,scanning strategy optimization,and processing algorithm improvement on radar observation data.In this paper,two different simulation methods of dual-polarization weather radar echo in the time domain and frequency domain are introduced.The frequency domain simulation method is based on the Gaussian power spectrum to construct the spectrum characteristics of weather radar echoes,and then the horizontal and vertical polarization echo signals are constructed by introducing dual channel amplitude,phase difference,and correlation.The time domain simulation meth-od is based on the autocorrelation function between pulse signals and builds the echo signal autocorrelation matrix.Then,the horizontal channel I/Q echo signal is obtained by Cholesky decomposition,and the vertical channel echo sig-nal is generated by using the double-channel amplitude,phase difference and correlation coefficient similar to the fre-quency domain modeling method.The simulation results show that both methods can realize the simulation of dual-polar-ization weather radar echoes.