Patent ID: 11867555
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 2:
3. A signal processing device comprising:
an input unit to which an in-phase component and an orthogonal component of scattered light generated at a wavelength-multiplexed light pulse incident on a measurement target optical fiber are input, the in-phase component and the orthogonal component being measured by a measuring device;
a vector acquisition circuit which acquires, for each wavelength multiplexed in the light pulse, a two-dimensional vector constituted by the in-phase component and the orthogonal component of the scattered light at an arbitrary time and an arbitrary position in the measurement target optical fiber;
a vector rotation circuit which rotates the two-dimensional vector of each wavelength at a reference time by a reference rotational amount for the wavelength so that the two-dimensional vector points in a reference direction and the two-dimensional vector of each wavelength at another time which is different from the reference time by the reference rotational amount for the wavelength; and
a calculation circuit calculates a synthesis reference vector as an arithmetic average of the two-dimensional vector of each wavelength at the reference time, a synthesis vector as an arithmetic average of the two-dimensional vector for each wavelength at the other time and a phase change amount of the scattered light based on an angle between the synthesis reference vector and the synthesis vector.