水下声场激光相干探测的特征提取与分析

Feature Extraction and Analysis of Underwater Acoustic Source with Laser Interferometry

激光相干探测法从水表面获取水下声场的信息,通过水表面反射光与参考光的干涉,从干涉信号中提取水下振动的频率。采用频谱分析与傅里叶滤波变换的特征提取方法,可有效地增强信号里水下声场的振动特征。振源在水下35 cm处,分别以1 000 Hz、2 000 Hz和3 200 Hz振动,激光相干探测从水面实时获取信息。通过对实验数据的分析表明,激光相干探测可以有效地获取水下声场振动的信息,傅里叶变换滤波方法能有效地增强目标的特征。

The information of the underwater acoustic field is obtained from the water surface by the laser co-herent detection method. The frequency of the underwater vibration is extracted from the interference signal by theinterference between the reflected light and the reference light on the water surface. The vibration features of the un-derwater acoustic field in the signal can be effectively enhanced by the method of spectrum analysis and fast Fouriertransform（FFT） filter feature extraction method. Laser coherent detection gets the information from the water surfacein real time under the condition that the vibration source is located underwater 35 cm, respectively with 1 000 Hz, 2000 Hz and 3 200 Hz vibration. Through experimental data analysis, the results show that the laser coherent detec-tion can effectively obtain the vibration information of underwater acoustic field, and FFT filter method can effective-ly enhance the features of the target.