基于异常单元删除的改进CFAR检测器  

Improved CFAR Detector Based on Anomalous Cell Deletion

作　　者：刘恒燕 熊伟 宋杰 周凯 梁晓军 李启超 LIU Hengyan;XIONG Wei;SONG Jie;ZHOU Kai;LIANG Xiaojun;LI Qichao(Naval Aviation University,Yantai 264001,China;Unit 91917 of PLA,Beijing 102100,China;Unit 91951 of PLA,Weihai 264200,China)

机构地区：[1]海军航空大学,山东烟台264001 [2]中国人民解放军91917部队,北京102100 [3]中国人民解放军91951部队,山东威海264200

出　　处：《雷达科学与技术》2019年第4期409-414,共6页Radar Science and Technology

基　　金：国家自然科学基金(No.61790554,61471380,61471381)

摘　　要：雷达在大入射余角海杂波下进行检测时易受到功率突然增大的杂波异常单元影响,虚警率及误检率较高。为解决此问题,提出具有杂波抑制模块与恒虚警模块的二级检测器。杂波抑制模块通过参考单元的协方差矩阵构造正定矩阵,求解其矩阵范数用以估计杂波功率水平,根据功率水平设置一个动态门限,剔除异常单元后的杂波作为待检测信号输入恒虚警模块,恒虚警模块使用基于有序数据可变性的自动删除平均(ACCA-ODV-)CFAR检测器来改进传统变化指数恒虚警(VI-CFAR)检测器。仿真结果表明,新检测器在均匀杂波环境中检测性能与单元平均恒虚警(CA-CFAR)检测器几乎相同,在多目标环境中检测性能远远优于最大选择恒虚警(GO-CFAR)检测器、最小选择恒虚警(SO-CFAR)检测器、CA-CFAR检测器及VI-CFAR检测器,在杂波边缘环境中虚警控制能力仅次于VI-CFAR检测器与GO-CFAR检测器。综合考虑实测数据中各个检测器的检测结果,改进后的检测器在高分辨率大入射余角情况下具有最优的检测性能。When detecting under the high-grazing-angle sea-clutter circumstances,radar is susceptible to the abnormal clutter cell whose power suddenly increases,which results in high false alarm rate and false detection rate.In order to solve this problem,a secondary detector with a clutter suppression module and a constant false alarm module is proposed.The clutter suppression module constructs a positive definite matrix with the reference-cell covariance matrix and solves its matrix norm to estimate the clutter power level.A dynamic threshold is set according to the power level to remove the abnormal clutter cell,and the rest of the signal in reference window is the input signal of the CFAR module as the signal to be detected.In CFAR module,we use an automatic censored averaging(ACCA-ODV-)CFAR detector based on ordered data variability to improve the traditional variability index constant false alarm(VI-CFAR)detector.The simulation results show that the detection performance of the new detector in the homogenous clutter environment is almost the same as that of the cell averaging constant false alarm(CA-CFAR)detector.The detection performance in the multi-target environment is far superior to the greatest of(GO-)CFAR detector,the smallest of(SO-)CFAR detector,CA-CFAR detector,and VI-CFAR detector.Only its false alarm control capability in the clutter edge environment is worse than VI-CFAR detector and GO-CFAR detector.Considering the detection results of each detector in the measured data,the improved detector has the best detection performance under the condition of high resolution and large grazing angle.

关 键 词：正定矩阵 大入射余角 高分辨率 改进CFAR检测器 

分 类 号：TN911.4[电子电信—通信与信息系统] TN957.5[电子电信—信息与通信工程]