PHASE READING Russian patent published in 2015 - IPC G01H9/00 

FIELD: measurement equipment.

SUBSTANCE: invention relates to metrology, in particular to phase meters for determination of acoustic or vibration disturbances. The method of distributed acoustic reading provides the measurement of derivative or rate of change of the signal scattered in the opposite direction in fiber. The method is implemented by sending of an input signal into a section of optical fiber, reception of the returned signal scattered in the opposite direction from the named optical fiber in response to the named input signal, comparison of the first returned signal scattered in the opposite direction from the section of the named fiber at the first moment of time, and the second returned signal scattered in the opposite direction from the same part of the named fiber in the second another moment of time. The first returned signal is modulated by the first frequency shift, and the named returned second signal is modulated by the second frequency shift. Then the rate of change of the phase in time for the named signal scattered in the opposite direction is calculated. The device contains an optical fiber, the receiver of the signal scattered in the opposite direction, the output interferometer containing the frequency modulator, the phase detector.

EFFECT: improvement of quality of phase component reading.

17 cl, 4 dwg