High sensitivity and large measurable range distributed acoustic sensing with Rayleigh-enhanced fiber

In this Letter, high sensitivity and large measurable range distributed acoustic sensing (DAS) based on sub-chirped-pulse extraction algorithm (SPEA) in time domain and dechirp operation is proposed; moreover, Rayleigh-enhanced fiber is used to further improve the quality of Rayleigh scattering (RS) signal. In the proof-of-concept experiment, the RS pattern with 60 µɛ strain range is generated during a single-shot measurement, while $80.7 \; {\rm p}\varepsilon /\sqrt {\rm Hz}$ strain sensitivity and 28.4 cm spatial resolution are achieved on 920 m fiber.