舰船辐射噪声特征线谱提取方法研究

The Method Research of Extracting the Characteristic Line Spectrum from the Ship-radiated Noise

线谱是船舶辐射噪声中重要的特征信息,为舰船的检测识别和方位跟踪提供了依据。采用Welch算法和CZT变换联合处理舰船的辐射噪声信号能够有效的提取线谱。Welch法在估计功率谱时可以有效减小方差和偏差,这有利于从宽带噪声谱中提取主要的窄带谱;CZT变换可以对窄带谱进行精确分析,提高频率的分辨力,因此这两者的结合有利于从舰船噪声中提取线谱。根据对仿真信号和某实船的辐射噪声信号的分析结果,表明该方法原理简单,能够精确地提取特征线谱,另外利用所提取的船只的特征线谱,还可以对船的航迹进行跟踪。

The characteristic line spectrum is the important imformation of the ship-radiated noise,and it provides a basis for the ship detection and azimuth tracking. Welch algorithm and CZT transform are combined to extract the line spectrum. The Welch algorithm can reduce the variance and bias effectively in estimating the power, spectrum, which is beneficial to extract the main narrow band spectrum from the broad band spectrum. The CZT transform can analyze the narrow band spectrum accurately and improve frequency resolution. Therefore, the combination of these two methods is beneficial for the extraction the line spectrum of ship noise of line spectrum from the ship-radiated noise. Both the simulation signal and the ship-radiated noise are analyzed. The result shows that the method proposed is simple in principle and able to extract line spectrum accurately. In addition, the ship-path can be tracked using the characteristic line spectrum of the ship.