DAS (Distributed Acoustic Sensor) is a system that can measure the position and frequency of a vibration source applied from the outside of the optical fiber.
DAS based on Phase OTDR is a system for measuring interfering signals caused by Rayleigh back scattered light generated when pulse light with narrow line width travels through optical fiber.
DAS can be applied to large-scale facilities, military iron wire, etc. depending on the detectable length & spatial resolution
Figure A. Schematic of DAS principle based on Rayleigh Scattering
Figure B. Schematic of DAS system
Figure C. External frequency and intensity measured by fiber length
Figure A. Schematic of DAS principle based on Rayleigh Scattering
Figure B. Schematic of DAS system
Figure C. External frequency and intensity measured by fiber length
Figure D. Application of DAS
