The invention belongs to the field of temperature
demodulation in a distributed
optical fiber sensing system, and discloses a double-path high-precision temperature
demodulation method based on a distributed
optical fiber Raman
sensing system. The method comprises the following steps: S1, carrying out device connection; S2, a calibration and measurement stage: respectively collecting
light intensity ratios of anti-Stokes light and Stokes light of each point in a reference
optical fiber ring and any position L of a sensing optical
fiber; S3, a calibration measurement stage: respectively collecting
light intensity ratios of backward anti-Stokes light and Stokes light of the sensing optical
fiber when a calibration optical
fiber ring is located at different positions, and carrying out calculation and
linear fitting to obtain all function values of a
temperature sensitive factor of the sensing optical fiber along with the distance; S4, a measurement stage: collecting the
light intensity ratio of the anti-Stokes light and the Stokes light of each point in the reference optical
fiber ring and each position in the sensing optical fiber; and S6, calculating to obtain all temperature information along the sensing optical fiber. According to the invention, the problem of low
temperature measurement precision in the prior art is effectively solved, and the method can be widely applied tothe distributed
optical fiber sensing system.