Distributed Fibre Optic Sensor Adaptive Spatial Resolution
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Solution Overview
Problem
Conventional distributed fibre optic sensors have fixed spatial resolution, limiting their flexibility and utility in applications requiring varying levels of sensitivity and noise management.
Innovation Solution
A distributed fibre optic sensor system that adjusts spatial resolution by varying the duration or separation of optical pulses, allowing for multiple spatial resolutions to be achieved simultaneously or in response to detected events, using techniques such as temporal variation and wavelength multiplexing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed spatial resolution is used in distributed fibre optic sensors, then the sensor structure is simple and easy to implement, but the flexibility and adaptability to different applications are limited
Solution Approach 1:
The patent implements dynamic spatial resolution by varying the pulse duration and/or separation time in the optical interrogation signal. This allows the sensing portions to be dynamically adjusted between different spatial resolutions (e.g., first and second spatial resolutions) without changing the physical sensor structure, thereby resolving the contradiction between adaptability and structural complexity
Solution Approach 2:
The patent changes the temporal parameters (pulse duration, pulse separation) of the optical interrogation signal to achieve different spatial resolutions. By modifying these parameters, the system can adapt to different application requirements while maintaining the same physical fibre optic sensor infrastructure
2Measurement precision
If higher spatial resolution is achieved by using shorter pulse durations, then the spatial resolution improves, but the signal-to-noise ratio deteriorates and sensitivity decreases
Solution Approach 1:
The system dynamically switches between different pulse durations based on the detection requirements. When high spatial resolution is needed, shorter pulses are used; when high sensitivity is needed, longer pulses are used. This dynamic adjustment allows the system to optimize the trade-off between spatial resolution and signal-to-noise ratio for different operational conditions
Solution Approach 2:
The patent employs periodic interrogation of the optical fibre with pulses of varying durations. By periodically switching between different pulse parameters, the system can accumulate sufficient signal energy for high sensitivity measurements while achieving high spatial resolution when required, thus resolving the contradiction between these two performance aspects
3Adaptability or versatility
If multiple spatial resolutions are provided simultaneously, then the versatility and adaptability improve, but the processing complexity and computational load increase
Solution Approach 1:
The patent segments the optical fibre into different sensing portions based on the pulse duration used. By using different pulse durations for different segments or for the same fibre at different times, the system provides multiple spatial resolutions. The processing is segmented accordingly, analyzing different portions of the backscatter signal for different resolutions, which manages the computational complexity
Solution Approach 2:
The system provides multiple spatial resolutions but processes them selectively based on detection needs. Not all resolutions are processed simultaneously for the entire fibre length; instead, the system processes only the necessary resolutions for specific sensing portions or event detection, reducing overall processing complexity while maintaining the capability for multiple resolutions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables flexible and adaptive monitoring with improved sensitivity and noise management, allowing for accurate detection and classification of acoustic disturbances over long fibre lengths with reduced processing overhead.
Implementation Method 1
an optical source configured to interrogate an optical fibre with optical radiation
Implementation Method 2
Any light which is Rayleigh backscattered within the optical fibre is detected and analysed
Data Source
AI summary
The invention relates to a distributed fiber optic sensor (104, 106) having a first spatial resolution (301, 303) and a second, different, spatial resolution (302, 304). The sensor, which may be a distributed acoustic sensor, has an optical source (112) configured to interrogate an optical fiber (104) with optical radiation and a detector (116) configured to detected optical radiation back-scattered from within the fiber. A processor (108) is configured to process the detected back-scatter radiation to provide a plurality of longitudinal sensing portions of fiber. The optical source and processor are adapted to provide the first and second spatial resolutions, for instance by changing the duration and/or separation of the optical pulses and analysis bins. The first and second spatial resolutions may be provided sequentially or simultaneously and the spatial resolution used may be varied as part of a default pattern or in response to a detection event.