基于两种方法的天气雷达谱宽估算质量比较与改进  

Quality Comparison and Improvement of Weather Radar Spectrum Width Estimation Based on Two Methods

作　　者：何田勇 胡明宝[1,2] 张振仟 艾未华[1] 孟鑫[1] 

机构地区：[1]解放军理工大学气象海洋学院,江苏南京211101 [2]南京气象雷达开放实验室,江苏南京210008

出　　处：《气象与减灾研究》2016年第3期216-223,共8页Meteorology and Disaster Reduction Research

基　　金：国家自然科学基金项目(编号:41475019)

摘　　要：采用FFT算法和PPP算法,对南京S波段双线偏振全相参脉冲多普勒天气雷达一次实测回波时域I/Q信号进行谱宽估计,并对谱宽估计值及其偏差与信噪比的关系进行了分析。结果发现:1)相对高信噪比数据,低信噪比回波的谱宽估计偏差更大,且随信噪比降低偏差呈指数增长。相对FFT算法,PPP算法的谱宽估计偏差更大,且随信噪比降低偏差增长速度更快。2)为提高谱宽估计精度必须要尽量消除噪声(主要是低信噪比回波信号)造成的影响,分别对FFT算法和PPP算法提出了改进方案,两种算法的谱宽估计质量都有了较大提升,尤其是低信噪比回波数据。修正后FFT算法处理得到的谱宽数据与RVP8偏差更小,而修正后PPP算法处理得到的谱宽数据偏差较大且比较离散,这表明FFT算法的估计精度更高,但实际处理过程中PPP算法的处理速度更快,两种谱矩估计算法各有优劣。Using the algorithm of FFT and the PPP to estimate the spectrum width of a practical echo time domain I/Q signal from S-band dual-polarization all form Doppler weather radar placed in Nanjing Lishui area,the spectrum width estimation and relationship between its deviation and the SNR are analyzed.The results show that:1)compared with high SNR data,the spectrum width estimation deviation of PPP algorithm is greater,and with the SNR decreasing,the deviation grows exponentially.Compared with algorithm of FFT,spectrum width estimation deviation of PPP algorithm is greater,and with the SNR decreasing,the deviation grows faster.2)To increase the spectrum width estimation precision,the effects of noise(mainly low SNR echo signal)must be eliminated.The solution of the FFT algorithm and the PPP algorithm are improved respectively,and the two kinds of algorithm of spectrum width estimation quality have greatly promoted,especially in low SNR echo data.The spectrum width deviation of revised FFT algorithm is smaller compared with RVP8,while spectrum width deviation of revised PPP algorithm is larger and discrete.The results show that the estimation precision of FFT algorithm is higher,while the PPP algorithm processing speed is faster.The two kinds of spectrum width estimation algorithm have their own advantages and disadvantages.

关 键 词：天气雷达 谱宽 信号处理 数据质量 

分 类 号：P415.2[天文地球—大气科学及气象学]