Noise Analysis of φ-OTDR Vibration Sensing System

Abstract

The interference principle of backscattering light in the optical fiber is analyzed theoretically and the sensing mechanism of φ-OTDR vibration sensor system is introduced briefly in this paper. The trace of backward Rayleigh scattering is obtained by MATLAB simulation, and it is compared to the scattering curve by experiment. The result shows that noise is inevitable in the experiment, and the desired signal is difficult to be detected for the high noise amplitude. For obtaining high SNR in the experiment, the compositions and causes of the noise is introduced and the effective suppression method are put forward.