Gamma分布在海面目标检测中的应用

本文通过对大量实测数据的处理与定量分析，证明Gamma分布可用于X波段雷达海杂波幅度分布的建模，并介绍了两种适用于Gamma分布杂波背景的恒虚警（CFAR）检测器：基于最大似然估计的MLG-CFAR和基于加权幅度循环迭代的WAI-CFAR。理论分析证明，MLG-CFAR检测器对Gamma分布的杂波平均功率估计值是渐进有效的，且在形状参数已知的前提下，该检测器对尺度参数具有恒虚警特性，在均匀、非均匀杂波背景中的检测性能仿真结果验证了该检测器在Gamma杂波中的最优性；WAI-CFAR检测器综合了均值类和有序统计量类CFAR算法的优点，在均匀杂波背景中具有较好的性能，在非均匀杂波背景中可通过灵活设定加权系数，获得较强的目标检测能力和鲁棒的虚警控制能力。

Applications of Gamma Distribution in Sea Clutter Modelling and Maritime Target Detection

The Gamma distribution is demonstrated to be promising to model the amplitude distribution of sea clutter based on experimental results. Furthermore, two CFAR detectors, namely the MLG-CFAR based on maximum likelihood estimation and the WAI-CFAR based on weighted amplitude iteration, are provided for Gamma-distributed background. Theoretical analysis shows that the derived estimator of the MLG-CFAR is an asymptotically efficient estimator of the mean power of the Gamma clutter. With a known shape parameter, the MLG-CFAR is demonstrated to maintain CFAR property with respect to the scale parameter of the Gamma distribution. Simulation results validate the superiority and generality of the MLG-CFAR in homogenous Gamma-distributed background. The WAI-CFAR is proposed by combining the advantages of cell averaging class CFAR detectors and ordered statistic class CFAR detectors. The superiority of the WAI-CFAR, which is applicable to different clutter scenarios with corresponding weighting factors, is investigated and verified by simulations.