Performance Improvement of Dual-Pulse Heterodyne Distributed Acoustic Sensor for Sound Detection

Sensors

Min Zhang¹  Fei Liu¹  Hailong Lu²  Xiangge He²  Lijuan Gu²  Shangran Xie³ 

[1] Beijing International Center for Gas Hydrate, Peking University, Beijing 100871, China;College of Engineering, Peking University, Beijing 100871, China;Max Planck Institute for the Science of Light, Staudtstr. 2, 91058 Erlangen, Germany;

关键词: distributed acoustic sensor;    rayleigh backscattering;    phase fading;    sound detection;   

DOI  :  10.3390/s20040999

来源: DOAJ

【 摘 要 】

Phase fading is fatal to the performance of distributed acoustic sensors (DASs) influencing its capability of distributed measurement as well as its noise level. Here, we report the experimental observation of a strong negative correlation between the relative power spectrum density (PSD) at the heterodyne frequency and the noise floor of the detected phase for the heterodyne demodulated distributed acoustic sensor (HD-DAS) system. We further propose a weighted-channel stack algorithm (WCSA) to alleviate the phase fading noise via an enhancement of the relative PSD at the heterodyne frequency. Experimental results show that the phase noise of the demodulated signal can be suppressed by 13.7 dB under optimal condition. As a potential application, we exploited the improved HD-DAS system to retrieve a piece of music lasted for 205 s, demonstrating the reliability of detecting wideband sound signal without distortion.

【 授权许可】

Unknown