基于快速迭代插值多普勒频率估计的单脉冲前视成像技术  

Monopulse Forward-looking Imaging Based on Doppler Estimation Using Fast Iterative Interpolated Beamforming Algorithm

作　　者：刘可 李悦丽 戴永鹏 金添 LIU Ke;LI Yueli;DAI Yongpeng;JIN Tian(College of Electronic Science and Technology,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学电子科学学院,长沙410073

出　　处：《雷达学报（中英文）》2023年第6期1138-1154,共17页Journal of Radars

基　　金：国家部委基金(50913030103)。

摘　　要：在单脉冲前视成像技术中,同分辨单元内多目标的辨识一直是单脉冲雷达的研究热点。尽管多普勒处理可以提高对前斜视多目标的分辨能力,但在真实目标数量未知、强点目标能量泄露的情况下,多普勒频率的精确估计面临巨大挑战。针对以上问题,该文在单脉冲前视成像中引入具有目标个数估计和单快拍处理能力的快速迭代插值波束形成(FIIB)算法,结合信息论准则估计目标个数,实现对多普勒频率的无偏估计。点目标仿真数值分析结果显示,FIIB对于同分辨单元内的目标数估计和参数估计性能优于调频Z变换(CZT)算法,能实现对±5°外点目标的准确估计。场景仿真和实测数据成像结果表明基于FIIB的单脉冲前视成像算法聚焦能力强,图像对比度更高,并能有效抑制背景杂波。Distinguishing multiple targets in the same resolution cell is an important and challenging task in the forward-looking imaging process of monopulse radar.Although Doppler processing can improve the recognition performance for multiple targets at high squint angles,the precise estimation of Doppler frequency remains challenging under conditions with unknown target numbers and energy leakage from strong point targets.To address these issues,this paper proposes a Fast Iterative Interpolated Beamforming(FIIB)algorithm with model order estimation and single snapshot processing for monopulse forward-looking imaging,which combines information theory to unbiasedly estimate the number of targets and Doppler frequencies.The simulation results show the superiority of the proposed FIIB algorithm over the Chirp-Z Transform(CZT)algorithm for estimating target numbers and Doppler frequencies within the same resolution cell in the presence of multiple point targets.In addition,the proposed FIIB algorithm can accurately estimate point targets beyond a±5°azimuth angle in monopulse angle measurement tasks.Real-data experiments also reveal that FIIB-based monopulse forward-looking imaging has high focusing capability and imaging contrast and can effectively suppress background clutter.

关 键 词：单脉冲雷达 前视成像 多普勒频率估计 快速迭代插值波束形成算法 

分 类 号：TN958.4[电子电信—信号与信息处理]