联合最小方差与最大似然谱估计的前视成像方法

Forward-looking imaging method by integrating minimum variance and maximum likelihood spectrum estimation

前视成像技术可用于高速运动平台相控阵雷达对正前方目标的检测和跟踪。为了解决波束内的目标分辨问题,提出一种联合最小方差与最大似然谱估计的前视成像方法。首先,进行波束扫描,采用最小方差谱估计获得初始的距离—方位二维图像;然后,对幅度峰值过门限的区域进行搜索,完成二次估计。仿真结果表明,所提方法可在相关信号和低信噪比等条件下有效改善目标分辨能力。

Forward-looking imaging technique can be used on phased array radar to detect and track the targets in front of the high speed motion platform.To solve the problem of discriminating the targets in the beamwidth,a forward-looking imaging method by integrating minimum variance and maximum likelihood spectrum estimation is proposed.Firstly,the approach of scanning the beam is used.The initial two-dimensional range-azimuth image is created with minimum variance spectrum estimation.Secondly,the regions in which the amplitude peaks exceed the threshold are searched to implement the second estimation.Simulation results have demonstrated the effectiveness of the approach to improve the targets’resolution capability in the applications involving correlated signals and low signal-to-noise ratios.