广义逆高斯纹理海杂波下微弱目标检测前跟踪算法

    Track-Before-Detect Algorithm for Weak Target in Sea Clutter with Generalized Inverse Gaussian Texture

    • 摘要: 在微弱目标探测领域,检测前跟踪(TBD)算法是当前的研究热点。它区别于传统的先检测后跟踪算法,不首先对量测数据进行门限检测,而是联合处理多帧数据。当复杂海况下类目标异常值出现频率较高时,目标往往被淹没在杂波中,传统的跟踪方法不再适用。现有的杂波环境下的TBD算法大多用K分布建模杂波,然而,K分布相比广义逆高斯纹理的复合高斯(CG-GIG)分布对杂波建模不够精细,目前CG-GIG分布在TBD中的研究还存在理论空白。本文首先推导了CG-GIG分布海杂波下的DP-TBD算法(GIG-TBD),海杂波建模为CG-GIG分布,目标建模为Swerling 3模型,采用对数似然比作为值函数;其次,针对对数似然比表达式没有闭式解的问题,提出了高效准确的近似方法;最后,通过矩估计得到海杂波参数。仿真对比了GIG-TBD、基于K分布推导的DP-TBD算法(K-TBD)和以幅度作为值函数的DP-TBD算法(A-TBD),仿真表明,在复杂海况下,GIG-TBD比K-TBD和A-TBD分别有2.5dB和6dB的检测性能增益,目标跟踪精度分别有50%和75%左右的提升;在一般海况下,GIG-TBD与K-TBD性能相近。

       

      Abstract: In weak target detection, Track-Before-Detect (TBD) algorithms have become a major research focus. Unlike traditional “detect-before-track” methods, TBD algorithms avoid threshold detection on individual measurements and instead jointly process multiple frames of data. Under complex sea conditions, where target-like outliers occur frequently, weak targets are often submerged in clutter and conventional tracking methods fail. Existing TBD algorithms for cluttered environments commonly model sea clutter using the K-distribution; however, the K-distribution provides a less refined characterization of clutter compared to the compound Gaussian model with generalized inverse Gaussian (CG-GIG) texture. To date, the application of the CG-GIG model in TBD remains largely unexplored.This paper derives a Dynamic Programming-based TBD (DP-TBD) algorithm under CG-GIG clutter, termed GIG-TBD. In this model, sea clutter is characterized by the CG-GIG distribution, targets are modeled following the Swerling 3 model, and the log-likelihood ratio (LLR) is employed as the merit function. To address the absence of a closed-form LLR expression, an efficient and accurate approximation method is proposed. Moreover, sea clutter parameters are estimated using the method of moments. Simulation results compare the proposed GIG-TBD with the K-distribution-based DP-TBD (K-TBD) and the amplitude-based DP-TBD (A-TBD). Under complex sea conditions, GIG-TBD achieves detection performance gains of approximately 3 dB and 6 dB over K-TBD and A-TBD, respectively, with corresponding track accuracy improvements of about 50% and 75%. Under moderate conditions, GIG-TBD and K-TBD exhibit comparable performance.

       

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