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

ABSTRACT: 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 r

SUBMITTER: He X 

PROVIDER: S-EPMC7070860 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature