基于高分辨信源估计的机载前视阵列雷达三维成像方法  

A Three-Dimensional Imaging Method Based on High Resolution Signal Source Estimation for Airborne Forward-Looking Array Radar

作　　者：刘向阳[1] 曾操[2] 毛志杰[1] 王静[3] 康连瑞[1] 

机构地区：[1]西安通信学院,陕西西安710106 [2]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071 [3]长安大学信息工程学院,陕西西安710064

出　　处：《电子学报》2013年第6期1048-1055,共8页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61101243;No.61101238;No.61102160);陕西省自然科学基金(No.2011JQ8036);中国博士后科学基金(No.20110491638;No.2012T50789);中央高校基本科研业务费(No.CHD2012ZD005)

摘　　要：结合阵列信号的信源数和波达方向估计技术,本文提出了一种适用于机载前视阵列雷达的三维成像方法.在前视阵列二维成像基础上,该方法首先对多个连续观测图像进行预处理,将脉冲阵列信号近似表示为多个正弦信号的和,然后利用阵列信号高分辨技术估计正弦信号的个数和频率,进而最后确定对应散射体的位置和幅度以实现三维成像.与传统三维匹配滤波成像方法不同,该方法利用宽带信号的匹配滤波实现沿航向的高分辨,利用多个连续观测图像构成的阵列信号实现高度向的高分辨;而且,由于仅需要几十个脉冲回波,该方法对载机飞行轨迹限制相对较少,载机可以实施相对灵活的机动飞行.与干涉测高三维成像方法相比,即使有多个散射体投影到同一个像素中,该方法也可以检测并分别恢复出每个散射体.另外,该方法利用待检测像素的数据直接估计杂波相关矩阵,在杂波严重非平稳情况下也能有效地实现三维成像.A three-dimensional imaging method for airborne forward-looking array radar is presented in this paper,in which the technique for the estimation of signal source number and direction of arrival（DOA）,usually used in array signal processing,is applied.On the basis of two-dimensional imaging,the vector constructed from the images among multiple continuous pulses could be presented as the summation of multiple sine signals from different scatters after the preprocessing of these images,and thus high resolution processing techniques could be used to estimate the number and the frequency of the sine signals,which can be applied to determine the three-dimensional image of the scene.Compared to the traditional imaging method with three-dimensional matched filtering, the method in this paper makes use of the matched filtering of the broadband signal to realize the high resolution over the along -track orientation,as well as the successive pulse signal to realize the high resolution over the altitude orientation.Moreover,the method can reduce the restriction to the flight trajectory because only dozens of pulses are used,and the aircraft can carry out flying more flexible.Compared to the interferometric three-dimensional imaging method,this method could detect and recover every scatter even if multiple scatters are projected to the same pixel,which is usually called for layover.Meanwhile,the method directly use the data in the same pixel for detection to estimate the image correlation matrix,and therefore can realize the there-dimensional imaging effectively even in the situation of seriously inhomogeneous images.

关 键 词：三维成像 前视阵列雷达 信源数估计 波达方向估计 空间平滑 

分 类 号：TN959.3[电子电信—信号与信息处理]