摘要
针对前视合成孔径雷达(synthetic aperture radar,SAR)方位分辨受限以及左右多普勒模糊问题,提出一种基于波达方向估计的前视多通道合成孔径雷达(forward-looking multi-channel SAR,FLMC-SAR)成像方法。算法综合利用系统空时资源,采用空时级联的处理流程。首先通过合成孔径对前视区域进行初步成像,在二维图像域实现逐个成像单元目标信号的分离。然后利用目标空域导向的差异,建立分离信号的空时模型,通过阵列多通道对每个成像单元内的信号进行波达方向估计,实现目标信号重定位,增强前视成像分辨率。同时,空时模型考虑了模糊目标具备不同的导向矢量,可在分辨增强的同时实现左右多普勒解模糊。最后通过仿真以及实测的FLMC-SAR数据验证了所提算法的有效性。
Aiming at the limited azimuth resolution and left-right Doppler ambiguity of forward-looking synthetic aperture radar(SAR),this paper proposes a direction of arrival(DOA)estimation based imaging algorithm for forward-looking multi-channel SAR(FLMC-SAR).The proposed algorithm comprehensively utilizes the system space-time resources and adopts the processing flow of space-time cascade.Firstly,the forward-looking area is preliminarily imaged through SAR,therefore the target signal of each imaging unit is separated in the two-dimensional image domain.Secondly,the space-time model of the separated signal is established by using the different spatial steering vector.The DOA estimation is performed on the signals in each imaging unit through the array multi-channel to realize the target signal relocation and enhance the forward-looking imaging resolution.Meanwhile,the space-time model takes into account the different steering vectors of the ambiguous target,which can realize the left-right Doppler ambiguity resolving and resolution enhancement.Finally,the simulation and real-data demonstrate the effectiveness of the proposed algorithm.
作者
王宁
贺鹏超
卢景月
刘曦
WANG Ning;HE Pengchao;LU Jingyue;LIU Xi(Xi’an Microelectronics Technology Institute,Xi’an 710065,China;School of Computer Science and Technology,Xidian University,Xi’an 710071,China)
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2023年第8期2471-2478,共8页
Systems Engineering and Electronics
关键词
合成孔径雷达
前视成像
左右多普勒模糊
分辨增强
波达方向估计
synthetic aperture radar(SAR)
forward-looking imaging
left-right Doppler ambiguity
resolution enhancement
direction of arrival(DOA)estimation
