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1. (WO2018035833) DISTRIBUTED FIBRE SENSING SYSTEM AND VIBRATION DETECTION AND POSITIONING METHOD THEREFOR

Pub. No.:    WO/2018/035833    International Application No.:    PCT/CN2016/096807
Publication Date: Fri Mar 02 00:59:59 CET 2018 International Filing Date: Sat Aug 27 01:59:59 CEST 2016
IPC: G01H 9/00
Applicants: SHANGHAI JIAOTONG UNIVERSITY
上海交通大学
Inventors: HE, Zuyuan
何祖源
LIU, Qingwen
刘庆文
CHEN, Dian
陈典
FAN, Xinyu
樊昕昱
Title: DISTRIBUTED FIBRE SENSING SYSTEM AND VIBRATION DETECTION AND POSITIONING METHOD THEREFOR
Abstract:
A distributed fibre sensing system and a vibration detection and positioning method therefor. The system comprises: a signal generating module, a light source module, an optical frequency comb generating module, a frequency sweeping string cutting module, an optical circulator, a sensing fibre, a beat frequency module, a photoelectric conversion module and a detection positioning module. The method comprises: a positioning unit in a detection positioning module generating a plurality of digital band-pass filters with different frequency bands without any overlapping, and performing digital filtering on original data segments from a plurality of swept-frequency detection optical pulses to obtain a plurality of reflectivity curves of a sensing fibre; performing fading elimination processing on the reflectivity curves to obtain a plurality of integrated reflectivity curves of non-interference fading and polarization fading; performing phase processing on the integrated reflectivity curves to obtain phase variance curves; and according to variances in the phase variance curves, determining a vibration point, and finally obtaining the position and a vibration waveform of the vibration point. According to the present invention, the positioning precision is high, the vibration frequency response range is large, and a signal-to-noise ratio of a vibration waveform is high.