Simultaneous Distributed Acoustic and Temperature Sensing System Using a Single Mode Fiber

We have simulated and experimentally validated a multi-parameter fiber optic sensing system using Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) with a single-mode fiber (SMF). The hybrid sensing system was achieved by measuring the phase of the Rayleigh backscattered radiation for DAS, as well as the intensity of the Raman Stokes and anti-Stokes for DTS. In the simulation and proof-of-concept experiments, signal to noise ratio (SNR) of 26.4 dB and 21.6 dB were achieved for an acoustic event with a frequency of 10 Hz located at 19.1 km. Concurrently, temperature measurements from 30°C to 100°C were obtained in both simulation and experiment, with uncertainty of 2.1 °C and 3 °C respectively at 6.1 km. The spatial resolution of the multi-parameter sensing system is 10 m for our experiments.