Abstract
Optical backscatter reflectometry (OBR) is an interferometric technique that can be used to measure local changes in temperature and mechanical strain based on spectral analyses of backscattered light from a singlemode optical fiber. The technique uses Fourier analyses to resolve spectra resulting from reflections occurring over a discrete region along the fiber. These spectra are cross-correlated with reference spectra to calculate the relative spectral shifts between measurements. The maximum of the cross-correlated spectra—termed quality—is a metric that quantifies the degree of correlation between the two measurements. Recently, this quality metric was incorporated into an adaptive algorithm to (1) selectively vary the reference measurement until the quality exceeds a predefined threshold and (2) calculate incremental spectral shifts that can be summed to determine the spectral shift relative to the initial reference. Using a graphical (network) framework, this effort demonstrated the optimal reconstruction of distributed OBR measurements for all sensing locations using a maximum spanning tree (MST). By allowing the reference to vary as a function of both time and sensing location, the MST and other adaptive algorithms could resolve spectral shifts at some locations, even if others can no longer be resolved.
| Original language | English |
|---|---|
| Article number | 6154 |
| Journal | Sensors (Switzerland) |
| Volume | 21 |
| Issue number | 18 |
| DOIs | |
| State | Published - Sep 2021 |
Funding
Funding: Development of the adaptive reference algorithms presented in this work was sponsored by the Transformational Challenge Reactor (TCR) Program (https://tcr.ornl.gov/) of the US Department of Energy Office of Nuclear Energy (DOE-NE). The experimental data were obtained using funding provided by the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory. Development of the adaptive reference algorithms presented in this work was sponsored by the Transformational Challenge Reactor (TCR) Program (https://tcr.ornl.gov/) of the US Department of Energy Office of Nuclear Energy (DOE-NE). The experimental data were obtained using funding provided by the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory. Acknowledgments: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Keywords
- Adaptive methods
- Distributed sensing
- Graph signal processing
- Optical backscatter reflectometry
- Optical fibers
- Optical frequency domain reflectometry