通过对水下航行器辐射噪声的多普勒特征分析,可以定位线谱噪声源在航行器上的辐射位置,从而有针对性地采取治理措施。传统的多普勒分析方法大多在时频域中进行,难以有效处理同频声源的定位问题。该文提出一种基于Chirp-Fourier变换特征的多普勒分析方法,将多普勒信号分解为线性调频(LFM)子分量的集合,并转换到频率一调频因子构成的2维平面。利用该平面内的多普勒信号分布特征,可以有效抑制同频声源之间的相互干扰,进而完成多噪声源的定位。仿真和海上实验验证了该方法的有效性。
The radiated noise sources of underwater vehicle can be localized by analysis of Doppler information. Then effective suppression of noise can be taken. However, traditional time-frequency methods can hardly distinguish the Doppler shift of noise sources with a single frequency. In this paper, a method of multi-Doppler signals analysis based on Chirp-Fourier transform is presented. The Doppler signal is decomposed into a sum of Linear Frequency Modulate (LFM) components, and transformed into two-dimensional frequency-modulate factor domain. Then the location of multiple noise sources can be estimated by the extracted Doppler information and the interference caused by single frequency sources can be suppressed. Computer simulation and experimental result at sea demonstrate the validity of the proposed method.