电离层测高仪回波中窄带干扰消除算法与分析  

Radio frequency interference mitigation algorithm in ionosonde

作　　者：陈锟[1] 朱正平[1] 宁百齐[2] 蓝加平[1] 孙奉娄[1] 

机构地区：[1]中南民族大学电信学院,湖北武汉430074 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《电波科学学报》2013年第2期391-396,共6页Chinese Journal of Radio Science

基　　金：国家自然科学基金仪器专项(41127003);湖北省自然科学基金重点项目(2010CDA062);国家科技基础性专项重点项目(2008FY120100)

摘　　要：针对Rife双谱线频率估计方法精度不高的问题,提出了改进的三谱线窄带干扰消除算法.利用快速傅里叶变换(Fast Fourier Transform,FFT)频谱中干扰主峰附近的3根谱线估算出窄带干扰频率,在干扰频点处做离散傅里叶变换(Discrete Fourier Transform,DFT)运算得到干扰幅度和相位.噪声背景下随机干扰估计结果表明:相比双谱线算法,三谱线算法的频率估计误差下降了约50%.应用于电离层测高仪回波干扰消除,对窄带强干扰的抑制达20～60dB,干扰抑制能力相比双谱线方法提高了1～6dB,消除干扰后的频高图描迹信息增多,可提高频高图反演电离层特征参数的准确性.The purpose of this work is to present further improved three-spectrumline method to reduce frequency estimation error in interference mitigation algorithm presently used in ionosondes. New method uses the three spectrum lines near the primary interference peak in fast Fourier transform（FFT）spectrum to calculate the frequency of interference. Then,the amplitude and phase of the interference are computed with discrete Fourier transform（DFT）method at known frequency. Computer simulation of random sinusoid estimation error in white noise background reveals that the frequency error of three-spectrum-line method is reduced by about 50 percent versus the double-spectrum line method that has been applied to ionosondes. Observational results of applying the new method to interferences mitigation of ionosondes echoes show that the strong narrow-band interferences of the echoes could be restrained by 20-60 dB and the interferences restraint capacity of three-spectrum-line method improved by 1-6 dB compared with double-spectrumline method. It is observed that the traces of ionograms where interferences are removed contained more sounding information and it is advantageous for inverting ionospheric characteristic parameters accurately.

关 键 词：电离层测高仪 脉冲雷达 干扰消除 频率估计 快速傅里叶变换(FFT) 

分 类 号：P352[天文地球—空间物理学]