为了提高对船舶水下轴频电场的远程探测能力,在充分分析实验室轴频电场信号的基础上,提出了一种基于小波空域相关的船舶轴频电场检测方法.首先使用小波空域相关对噪声和信号进行分离,并给出一种针对轴频电场的噪声阈值估计方法;然后,提取信号特征频率范围内的能量作为特征值,对信号进行滑动功率谱检测.对比分析结果表明,该算法在低信噪比情况下具有更高的稳定性和更好的检测效果.
The ship shaft-rate(SR) electric signal,as an important kind of target characteristic,plays an important part in signal detection.In order to improve the remote-detecting capability of ship shaft-rate electric field,a novel detection algorithm based on spatially selective noise filtration in the wavelet domain was proposed.First,the signal and noise was separated by the spatially selective noise filtration in the wavelet domain.Then the arithmetic of estimating noise energy threshold of SR electric signal was proposed.Finally,the signal energy in the feature spectrum was extracted to detect the target by the sliding power spectrum algorithm.The effectiveness of the algorithm was verified by the data measured both in the laboratory and seawater.The verified result shows that the algorithm can detect the weak shaft-rate electric signal more effectively at lower SNR situations.