基于Rao检测器的舰船轴频电场滑动门限检测方法

为实现非高斯背景噪声和低信噪比情况下的舰船轴频电场检测，提出一种基于Rao检测器的滑动门限检测方法。基于信号源特征建立信号模型，在对水面浮动平台测量背景下环境噪声非高斯特性分析基础上，采用混合高斯模型对噪声进行建模；在检测过程中，实时估计混合高斯噪声模型参数和Rao检测统计量，并将前一段时间的平均Rao检测统计量作为门限，实现滑动门限检测。为验证所提方法的有效性，采用仿真计算的方式，证明Rao检测方法相比于能量检测方法的优势；根据实测数据，对比滑动门限Rao检测方法与滑动功率谱检测方法的性能差异。结果表明，滑动门限Rao检测方法能够有效抑制环境非高斯噪声影响，相比滑动功率谱检测方法具有更好的检测效果。

Ship Shaft-rate Electric Field Sliding Threshold Detection Method Based on Rao Detector

A sliding threshold detection method based on Rao detector is proposed to detect the ship's shaft-rate electric field at a low SNR in non-Gaussian noise environment. A signal model is established based on the characteristics of signal source, and a noise model is established based on Gaussian mixture model (GMM) after analyzing its non-Gaussian characteristics measured by a floating platform. In the detection process, the parameters of GMM and the Rao detection value are computed in real time; the mean value of previous Rao detection values is regarded as the sliding threshold. The simulation method is first used to verify the proposed method. The results show that the detection performance of Rao detector is better than that of energy detector. Then the measured ship data is used to compare the Rao sliding threshold method and the sliding power spectrum method. The results show that the proposed method is better in decreasing the non-Gaussian environment noise and has a better detection performance than the sliding power spectrum method.