高频地波雷达中电离层杂波的时频特征  

Time-frequency characteristics of the ionospheric clutters in high-frequency surface wave radars

作　　者：周浩[1] 文必洋[1] 吴世才[1] 

机构地区：[1]武汉大学电子信息学院,湖北武汉430079

出　　处：《电波科学学报》2009年第3期394-398,共5页Chinese Journal of Radio Science

基　　金：国家高科技发展计划项目(No.2007AA09Z101)

摘　　要：高频地波雷达中的电离层杂波通常可分为聚集区和扩展区,聚集区杂波对应于经电离层直接反射的回波,距离扩展较小,表现为单(或多)分量调幅-调频(AM-FM)信号;扩展区对应于复杂混合路径的回波,具有较大的距离域和时频域扩展。电离层聚集区杂波在距离上的相关性明显高于正常海洋回波,而扩展区杂波的距离相关性则相对较弱。利用雷达杂波的时频特征,可以对电离层聚集区回波进行时频面掩模处理抑制强杂波,或利用相邻距离元上的回波信号进行杂波对消。雷达实测数据处理结果表明上述分析和杂波抑制方法是有效的。Ionospheric clutter in high frequency surface wave radar can usually be separated into the concentrated region and the spread region, Clutter in the concentrated region results from the directly reflected echoes from the ionosphere, having a small range extension and monople or multiple component amplitude-modulated and frequency-modulated （AM-FM） components. Clutter in the spread region resuits from echoes propagated through mixed ionosphere-sea paths, having a large range extension and a spread time-frequency distribution. The concentrated clutter has a higher range-domain correlation than the sea echoes, while the spread clutter has a relatively smaller correlation. Utilizing the characteristics, clutter in the concentrated region can be suppressed by masking the strong ridges on the time-frequency plane or be cancelled across neighboring range bins. Real data processing results show the validness of the above analysis and clutter suppression methods.

关 键 词：高频地波雷达 电离层杂波 时频分析 对消 

分 类 号：TN911.72[电子电信—通信与信息系统]