噪声谱分析是水下目标辐射噪声特征提取的重要手段。为了提高辐射噪声时频表征的准确度，本文引入同步特征提取（SET）算法，它使用瞬时频率处的时频系数作为同步提取算子，以获取瞬时频率的准确估计。然后，采用短时傅里叶变换（STFT）算法及SET算法对2组舰船仿真信号及1组实测信号进行时频分析，并引入Renyi熵值作为量化指标。结果表明，相较于STFT算法，SET算法能够有效提高辐射噪声信号时频谱的能量集中度和时频分辨率，有助于精确提取关键线谱信息，进而分析获取水下目标的轴频、桨叶数、主机辅机振动频率等重要特性。
Noise spectrum analysis is a common method of characterizing radiated noise from underwater targets. In order to improve the time-frequency characterization of radiated noise, we introduce the synchroextracting transform (SET) algorithm. SET could obtain the accurate estimation of the instantaneous frequency with the time-frequency coefficients at the instantaneous frequency as the synchronous extraction operator. The short-time Fourier transform (STFT) algorithm and SET algorithm were employed to analyze the ship simulation signals and measured signals. What’s more, the Renyi entropy was introduced as the quantitative index. The results showed that, compared with the STFT, SET effectively enhanced the energy concentration and time-frequency resolution of the time-frequency spectrum of the radiated noise signals, which could be critical for extracting the key line spectral information. Furthermore, the characteristics of the underwater target such as the shaft frequency, number of paddles, and vibration frequency of the main engine and auxiliary engines could be obtained based on the result.
2025,47(10): 138-143 收稿日期：2024-7-25
DOI：10.3404/j.issn.1672-7649.2025.10.023
分类号：U666.73
作者简介：刘倩雯（1997-），女，硕士，助理工程师，研究方向为水声信号处理
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