Cancellation of reference update-induced 1/f noise in a chirped-pulse DAS

Autor: Pedro J. Vidal-Moreno, Etienne Rochat, Pablo Fermoso, María R. Fernández-Ruiz, Hugo Martins, Sonia Martin-Lopez, Manuel Ocaña, Miguel Gonzalez-Herraez
Přispěvatelé: European Commission, Ministerio de Ciencia e Innovación (España), Comunidad de Madrid, Universidad de Alcalá
Rok vydání: 2022
Předmět:
Zdroj: Optics letters. 47(14)
ISSN: 1539-4794
2021-0078
Popis: 4 pags., 4 figs.
Distributed acoustic sensors (DAS) perform distributed and dynamic strain or temperature change measurements by comparing a measured time-domain trace with a previous fiber reference state. Large strain or temperature fluctuations or laser frequency noise impose the need to update such a reference, making it necessary to integrate the short-term variation measurements if absolute strain or temperature variations are to be obtained. This has the drawback of introducing a 1/f noise component, as noise is integrated with each cumulative variation measurement, which is detrimental to the determination of very slow processes (i.e., in the mHz frequency range or below). This work analyzes the long-term stability of chirped-pulse phasesensitive optical time-domain reflectometry (CP-φOTDR) with multi-frequency database demodulation (MFDD) to carry out "calibrated"measurements in a DAS along an unmodified SMF. It is shown that, under the conditions studied in this work, a "calibrated"chirped-pulse DAS (CP-DAS) with a completely suppressed reference update-induced 1/f noise component is achieved capable of making measurements over periods of more than 2 months with the same set of references, even when switching off the interrogator during the measurement.
European Commission (PSI ref. PLEC2021-007875); Gobierno de España (RTI2018–097957-B-C31, RTI2018–097957-BC33); Ministerio de Ciencia e Innovación (IJC2018–035684-I, MCIN/AEI/10.13039/501100011033); Comunidad de Madrid (SINFOTON2-CM:S2018/NMT-4326); Universidad de Alcalá (FPI-Program, 2020/00198/001 - UAH INFR. A 2020-007)
Databáze: OpenAIRE
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