Abstract

ϕ-OTDR/DAS enables dense, long-range (1 - 200 km), array recordings of strain fields with exceptional sensitivity ( < 1 × 10^-9 strain) wherever optical fiber exists. The measurement is conventionally based on interferometrically extracting dynamic phase information of the Rayleigh backscattered light from one end of a single-mode fiber. Recently, ϕ-OTDR/DAS has expanded into telecommunications networking, seismology and geophysics, water infrastructure monitoring, and civil engineering.

© 2023 The Author(s)