High-frequency high-resolution distributed acoustic sensing by optical frequency domain reflectometry.

Area of Science:

• Optics and Photonics
• Signal Processing
• Sensor Technology

Background:

• Distributed Acoustic Sensing (DAS) using Optical Frequency Domain Reflectometry (OFDR) is crucial for various monitoring applications.
• Existing OFDR-DAS systems face limitations in achieving both high acoustic bandwidth and high spatial resolution simultaneously.
• Non-idealities and phase noise in optical measurements can degrade the performance of DAS.

Purpose of the Study:

• To propose a novel data analysis algorithm for OFDR-based DAS.
• To achieve high acoustic bandwidths (tens of kHz) and high spatial resolutions (centimeters).
• To analyze and compensate for non-idealities and phase noise in the OFDR-DAS system.

Main Methods:

• Development of a specialized data analysis algorithm tailored for OFDR-DAS.
• Analysis of system non-idealities, including phase noise effects on measurements.
• Experimental demonstration of a compensation method for identified non-idealities.
• Extensive experimental testing to evaluate sensor performance.

Main Results:

• The proposed algorithm enables high acoustic bandwidths reaching tens of kilohertz.
• Sharp spatial resolutions on the order of centimeters were achieved.
• A method for compensating non-idealities and phase noise was successfully demonstrated experimentally.
• Experimental validation confirmed the viability of the technique.

Conclusions:

• The developed data analysis algorithm significantly advances OFDR-based DAS capabilities.
• The technique successfully overcomes limitations in achieving high frequency and high spatial resolution simultaneously.
• The demonstrated compensation method enhances the robustness and accuracy of OFDR-DAS systems.