The invention discloses a
wavelength division
multiplexing phi-OTDR and BOTDR fusion
demodulation method,
system and device and a storage medium, and relates to the technical field of distributed
optical fiber sensing, and the method comprises the steps: employing a double independent narrow linewidth
laser to output continuous
laser, enabling each path to be divided into two beams through a coupler, enabling one beam to be subjected to pulse modulation, and enabling the other beam to be used as local oscillation light;
pulse light is modulated into frequency-shift
pulse light through an acousto-optic modulator, and the frequency-shift
pulse light is injected into a sensing
optical fiber after being combined by an optical combiner. And the backscattered light is separated by the optical wave separator according to the
wavelength. Rayleigh signals are subjected to coherent receiving and orthogonal
demodulation to obtain
light intensity; brillouin
signal amplification,
frequency mixing and the like are performed to extract
frequency shift. In combination with
light intensity and
frequency shift, temperature strain is decoupled, and vibration information is demodulated; according to the invention, the
measurement precision is improved, and the line
potential risk can be found in time; efficient
signal isolation and transmission and temperature strain decoupling measurement are achieved, and pipeline safety is guaranteed; the structure is simple and easy to expand, and long-distance, low-cost and high-precision monitoring and timely disaster early warning can be realized.