摘要
螺旋桨轴频是被动声纳极其重要的目标识别特征之一。为了能在低信噪比下正确估计出螺旋桨的轴频,本文模拟人类专家通过分析DEMON图确定螺旋桨轴频的过程,给出了一个自动估计螺旋桨轴频方法。该方法包含两个阶段:第一阶段利用双门限线谱检测方法提高螺旋桨轴频及其谐波对应的线谱的检测性能;第二阶段利用处理后的线谱之间的间隔估计轴频。试验结果表明,本文提出的方法在低信噪比下能够正确估计螺旋桨轴频,明显取得了较好的分析结果。
The propeller shaft frequency is one of the important target recognition features for passive sonar. In order to estimate propeller shaft frequency correctly at low signal to noise ratio, we imitate the processes that human experts determine the propeller shaft rate by analyzing the waterfall representation of the DEMON spectrum (DEMONgrams), and give an automatic method of estimating propeller shaft frequency in this paper. The proposed method has two stages: In the first stage, we make use of double thresholds line-spectrum detection method to improve the detection performance of line-spectra associated with the propeller shaft frequency and harmonic frequency; At second stage, the spaces of each processed line-spectrum is used to estimate propeller shaft frequency. The analysis shows that this method can estimate propeller shaft frequency correctly, and give better results compared to the methods which only make use of one frame demon spectra to estimate propeller shaft frequency at very low SNR.
出处
《信号处理》
CSCD
2004年第5期461-464,440,共5页
Journal of Signal Processing
