High-Spatial-Resolution Distributed Acoustic Sensor Utilizing a Positive- and Negative-Swept Pulse

• DOI: 10.1109/jlt.2023.3344936
• Publication Date: 2023-12-20T19:35:10Z
• Authors: Xunzhou Xiao; Jun He; Bin Du; Baijie Xu; Guanfeng Chen; Xizhen Xu; George Yuhui Chen; Yiping Wang
• Keywords: Reflectometry; Pulse compression; Distributed Acoustic Sensing; Heterodyne detection

A distributed acoustic sensor (DAS) with a one- centimeter spatial resolution is proposed and demonstrated using pulse-compression phase-sensitive optical time-domain reflectometry (Φ-OTDR). positive- negative- swept pulse was used to expand the frequency modulation range of heterodyne DAS system achieve high resolution. Rayleigh-enhanced single-mode fiber (eSMF) magnify backscattering signal suppress fading noise. The combination compression eSMF allows fully quantify perturbations 1.2 cm strain 1.46 nϵ/√Hz. In addition, detection positioning multiple emission (AE) sources at frequencies 120∼130 kHz also demonstrated. Hence, high-spatial-resolution in this work could potentially be for structural health monitoring large equipment, such as spacecrafts, hypersonic vehicles, deep-sea submersibles.