一种天波超视距雷达电离层相位污染联合校正方法  

A Joint Method to Correct Ionospheric Phase Perturbation in Over-the-horizon Radar

作　　者：罗欢[1] 陈建文[2] 鲍拯[2] 

机构地区：[1]空军预警学院研究生管理大队,武汉430019 [2]空军预警学院三系,武汉430019

出　　处：《电子与信息学报》2013年第12期2829-2835,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61072132)资助课题

摘　　要：天波超视距雷达(OTHR)利用电离层的反射实现远距离探测。由于受到电离层时变因素的影响,在长相干积累时间条件下,回波谱会发生展宽,严重影响OTHR对舰船等低速目标的检测能力。针对OTHR回波受到电离层相位污染后正负Bragg展宽峰发生交叠的情况,该文提出了一种联合短时MUSIC变换(STMT)和改进相位梯度(PGA)法的校正方法(即ST_IPGA法)。该方法首先利用STMT变换得到相位污染的粗估计,对污染回波进行初步补偿;然后采用自适应滑窗滤波器提取纯净且完整的海杂波标校信号;最后利用改进的PGA法估计出剩余相位污染,对污染回波进行精确校正。理论分析和仿真结果表明该方法对于校正严重电离层相位污染导致的正负Bragg展宽峰发生交叠的情况具有明显的效果。Skywave Over-The-Horizon Radar （OTHR） can achieve long range detection via the ionosphere reflection. However, time-varying ionosphere and multipath effect will lead to serious clutter spectrum spread in long Coherent Integration Time （CIT）. It increases difficulty degree of the detection of slow-speed targets. To deal with contaminated echo in the case of the two spreading Bragg peaks overlapping, an ionospheric contamination correction scheme based on Short Time MUSIC Transform （STMT） and improved Phase Gradient Autofocus （PGA） method is proposed. In the scheme, coarse estimation of ionospheric phase contamination can be obtained and compensated by using STMT transform, then an adaptive sliding window filter is utilized to extract the first order clutter （calibration signal）. After that, the remanent ionospheric phase contamination can be estimated and compensated accurately by using improved PGA method. Theoretical analysis and simulation results show that the scheme has a good performance on correcting the situation of two spreading Bragg peaks overlapping.

关 键 词：天波超视距雷达(OTHR) 电离层相位污染 短时MUSIC变换 相位梯度(PGA)法 

分 类 号：TN958[电子电信—信号与信息处理]