Ultra-low sampling resolution technique for heterodyne phase-OTDR based distributed acoustic sensing
Feihong Yu, Shuaiqi Liu, Liyang Shao, Weijie Xu, Dongrui Xiao, Fang Zhao, Jie Hu, Weihao Lin, Guoqing Wang, Weizhi Wang, Feng Wang, Huanhuan Liu, Perry Ping Shum
Abstract
Phase-sensitive optical time-domain reflectometry (Φ-OTDR) based on heterodyne detection is widely used for its simple structure and high signal-to-noise ratio (SNR). However, the large amount of raw data of Φ-OTDR places a heavy burden on the storage device and also limits the transferability of the data. In this Letter, we propose an ultra-low sampling resolution technique to solve the data storage problem in heterodyne Φ-OTDR. Experimental results show that the optical phase variations induced by external vibrations can be successfully demodulated from the 1-bit-resolution raw data, and a vibration SNR of 58.03 dB is achieved. In addition, this work also reveals that a data acquisition device with extremely low sampling resolution is sufficient for heterodyne Φ-OTDR, signifying that the cost of the system can be further decreased.