低频线谱检测ALE算法应用

 舰船辐射噪声在低频段具有稳定的特征信息丰富的线谱成分,此线谱成分的检测对水下目标的定位和识别具有重要意义.为了有效地将舰船辐射噪声特征线谱从宽带背景噪声中分离出来,应用ALE算法理论对舰船噪声信号进行研究.ALE算法作为自适应FIRDF算法的一种变形,是自适应噪声抵消器的典型应用.低频线谱检测中采用ALE算法无需参考信号,自适应地将线谱成分信号进行匹配,可以从宽带噪声中将线谱成分分离出来,且线谱成分明显增强.理论分析仿真结合实际海试数据对LOFAR谱图进行研究,结果表明,ALE算法在低频线谱信号检测中能够达到期望的效果.与常规方法相比,检测性能得到有效提高,有利于辐射噪声线谱的提取.

Applications of Adaptive Line-spectrum Enhancement Algorithm to the Detection of Low Frequency Line-spectrum Signal

The ship-radiated noise possesses a stable part of the line-spectrum at low frequency range, containing rich information, and it is meaningful for positioning and distinguishing underwater targets. In order to separate the ship-radiated noise line-spectra from the broadband background noise effectively, the method for analyzing the ship-radiated noise signals by using Adaptive Line-spectrum Enhancement (ALE) algorithm is put forward. As a variant of adaptive Finite Impulse Response (FIR) Digital Filter (DF), ALE is a typical application of adaptive noise canceller. The algorithm is able to find and match the line-spectrum signals and separate them from wide band addictive noise without reference signals. Then, the line-spectrum signals could be enhanced. By theoretical analysis simulation and actual ocean-trial, the research on the Low Frequency Acquisition and Ranging (LOFAR) spectrum shows that ALE algorithm is able to meet the expectation competently. Comparing with conventional methods, the detection performance enhances observably, and radiated noise line-spectra are able to be effectively extracted.