基于四阶累量对角切片谱的线谱估计方法

研究了一种基于信号四阶累量对角切片谱的时频分布图的水中目标辐射噪声的线谱估计方法。分析了四阶累量对角切片谱具有的性质,即抑制高斯噪声和对称分布噪声;与功率谱具有相似的谱结构。介绍了Lofar处理的特点和Lofar谱图的计算步骤。结合Lo-far谱图和四阶累量对角切片谱的各自特点,提出了四阶累量对角切片谱图的处理方法。再利用图形学中的Radon变换,将谱图中的直线转换成Radon域中的峰值。得到峰值坐标后,可以计算谱图中的线谱频率等参数。仿真实例表明,该方法效果明显。

A Line Spectrum Estimation Method Based on the Fourth-order Cumulant Slice Spectrum

A line-spectrum estimation method of underwater target radiated noise is studied,and the method is based on Fouth-order cumulant slice spectrum.The characteristic of fourth-order cumulant slice spectrum is analyzed.Using fourth-order cumulant slice spectrum,the gauss-white noise and symmetry distribution noise can be reduced,and the spectrum structure is similar with power spectrum.The characteristic and calculating process of Lofargram is introduced.The calculating method of fourth-order cumulant slice spectrum diagram is introduced with analyzing the characteristic of Lofargram and fourth-order cumulant slice spectrum diagram.The line in the fourth-order cumulant slice spectrum diagram can be transformed into peak value in the Radon-domain using Radon transform.After the peak value is gained,the frequency and frequency modulation can be calculated.At last,simulation results show that this algorithm is effective.