Authors:
Javier Preciado
1
;
David Sanahuja
2
;
Carlos Heras
2
;
Jesús Subías
3
;
Lucía Hidalgo
2
;
Iñigo Salinas
2
;
Pascual Sevillano
4
;
Juan José Martínez
4
and
Asier Villafranca
4
Affiliations:
1
Departamento de Ingeniería Electrónica y Comunicaciones, EINA, Universidad de Zaragoza, C/María de Luna 1, 50018 Zaragoza, Spain, Aragón Photonics Labs (APL), Prado 5, 50009 Zaragoza and Spain
;
2
Departamento de Ingeniería Electrónica y Comunicaciones, EINA, Universidad de Zaragoza, C/María de Luna 1, 50018 Zaragoza and Spain
;
3
Departamento de Física Aplicada, Ciencias, Universidad de Zaragoza, C/María de Luna 1, 50018 Zaragoza and Spain
;
4
Aragón Photonics Labs (APL), Prado 5, 50009 Zaragoza and Spain
Keyword(s):
Distributed Acoustic Sensor, Distributed Fiber Sensing, Accelerometer Sensor, Calibration.
Related
Ontology
Subjects/Areas/Topics:
Photodetectors, Sensors and Imaging
;
Photonics
;
Photonics, Optics and Laser Technology
Abstract:
Distributed acoustic sensors (DAS) based in coherent optical time-domain reflectometry (C-OTDR) provide a cost-effective solution for intrusion monitoring of large civil infrastructures like pipelines, railways or motorways. Although detection of events is well demonstrated, an estimation of the amplitude of these events is difficult to achieve. We propose a new method to recover the amplitude of the vibration from the conventional C-OTDR backscattered power traces. It is based on the FFT analysis of the DAS signals. Using a discrete accelerometer as a reference, we have calibrated the response of an optical fiber DAS using known stimuli. A correlation between the amplitude of the vibration and the ratios of the amplitudes of harmonics to the fundamental of the DAS signals is demonstrated. This analysis overcomes the main issues of the amplitude measurement, related to the interaction between the stimulus and the interference pattern.