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US 2026/0251508 A1Published application
Phase otdr
AssigneeNTT, Inc.
InventorsYoshifumi WAKISAKA, Hiroshi TAKAHASHI, Daisuke IIDA, Yukihiro GOTO, Yusuke KOSHIKIYA
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AssigneeNTT, Inc.
InventorsYoshifumi WAKISAKA, Hiroshi TAKAHASHI, Daisuke IIDA, Yukihiro GOTO, Yusuke KOSHIKIYA
Estimating the term…
An object of the present disclosure is to provide a phase OTDR, a signal processing device, and a signal processing method capable of reducing an influence of a phase connection error and improving visibility of a signal indicating a vibration change or a temperature change. According to the present disclosure, there is provided a signal processing device 14, which is included in a phase OTDR 301 and is configured to: measure a phase of backscattered light; express a temporal change of an amount of expansion/contraction occurred in an arbitrary section of an optical fiber as a difference between the phases at both ends of the section; perform unwrapping processing on the difference between the phases in a time axis direction and generate a waveform 40 of a phase Δθc after the unwrapping processing; generate a moving average waveform 43 by calculating a moving average of the waveform 40 by moving a window 41 having a window length W, corresponding to a predetermined time, in a time axis direction 42; and generate a corrected waveform 44 of a corrected phase difference Δθc2 by subtracting the moving average waveform 43 from the waveform 40.
A phase OTDR comprising:
A signal processing device that performs calculation on an electrical signal that is generated by a phase OTDR, which includes a light source which inputs a light pulse to a measurement target optical fiber and a light receiving unit that receives backscattered light of the light pulse and outputs the electrical signal, the signal processing device being configured to:
A signal processing method that performs calculation on an electrical signal that is generated by a phase OTDR, which includes a light source which inputs a light pulse to a measurement target optical fiber and a light receiving unit that receives backscattered light of the light pulse and outputs the electrical signal, the signal processing method comprising:
Dependencies are inferred from the claim text.