Optical fiber sensing dynamic signal demodulation method based on spectral fitting and difference algorithm

Abstract

The invention discloses an optical fiber sensing dynamic signal demodulation method based on spectral fitting and a difference algorithm. The method comprises the following steps: performing scanning to obtain spectral ripples; fitting the spectral ripples to obtain a static spectrum; performing difference processing on the spectral ripples and the static spectrum to obtain difference signals; fitting extreme points of the spectral ripples to obtain upper and lower edge envelope curves; performing difference processing on the upper and lower edge envelope curves to obtain a spectral change function, performing normalization processing on the difference signals and the spectral change function to obtain envelope-removed difference signals, converting wavelength into time according to scanning speed and initial wavelength to obtain envelope-removed time-domain dynamic signals. According to the method, the dynamic signals are obtained by performing difference processing on the spectral ripples and a fitting curve of the spectral ripples, environmental interference such as temperature, humidity and the like can be eliminated, and the recovered dynamic signals hardly have dc component; meanwhile, broadband light is taken as input of an optical fiber sensor, and the complexity of an optical fiber sensing device is reduced.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a method for demodulating dynamic signals of optical fiber sensing based on spectrum fitting and differential algorithms. Background technique [0002] In recent years, due to the continuous occurrence of natural disasters and safety accidents such as earthquakes, mine accidents, and oil pipeline leakage, acoustic wave and vibration signal sensing has attracted more and more attention. Compared with traditional electrical or mechanical sensors, dynamic signal sensors based on optical fiber technology have the advantages of small size, light weight, anti-electromagnetic interference, corrosion resistance, and easy networking and multiplexing. In order to realize the accurate measurement of the dynamic signal, the demodulation method of the optical fiber sensing dynamic signal has also been extensively studied by scholars at home and abroad. Accurate meas...

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Problems solved by technology

[0004] Aiming at the above defects and improvement needs of the prior art, the present invention provides a dynamic signal demodulation method of optical fiber sensing based on spectrum fitting and difference algorithm, aiming to solve the problem of demodulation caused by the influence of environmental interference on the existing demodulation method. Technical issues with inaccurate signals

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