基于FOCUSS的水中目标回波亮点高分辨提取方法

水中目标回波亮点空间分布是估计目标尺度、确定目标要害部位、目标识别分类的主要目标特性依据。分析了水中目标回波亮点提取的主要方法及其优缺点,针对提高水中目标回波亮点方位估计分辨率的问题,采用欠定系统局域解法(Focal Undetermined System Solver,FOCUSS)压缩感知信号处理方法估计目标回波亮点的方位分布,并与时域常规波束形成(Conventional Beamforming,CBF)方法、子阵最小方差无失真响应(Minimum Variance Distortionless Response,MVDR)波束形成方法进行了比较。试验数据处理结果表明,FOCUSS压缩感知方法的回波亮点方位输出主瓣是"针形"的且无明显旁瓣,分辨率高于子阵MVDR、CBF波束形成处理结果。另一方面,FOCUSS压缩感知方法对信噪比的要求高,适用于良好信噪比条件下的回波亮点提取。

A high resolution method of echo highlight extraction based on FOCUSS algorithm

The spatial distribution of echo highlights is the main characteristics of underwater target for target length estimation, vital parts location, target recognition and classification in active sonar application. The ad-vantages and disadvantages of various methods for echo highlight extraction are discussed in this paper. In order to improve the resolution of highlights in the aspect domain, the compressive sensing algorithm of FOCal Undetermined System Solver (FOCUSS) is applied to aspect angle estimation in echo highlights extraction processing. Meanwhile the proposed method is compared with Conventional Beamformer (CBF) and sub-array Minimum Variance Distortionless Response (MVDR) algorithm. Through measured data processing, the results show that the output of the FOCUSS algorithm has a needle shaped main-lobe with unobvious side-lobes and its resolution is higher than that of CBF and sub-array MVDR processing. On the other hand, a higher signal-to-noise ratio is demanded in the FOCUSS algorithm for highlight extraction application.