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Enhancing the performance of BOTDR based on the combination of FFT technique and complementary coding
Optics Express
|March 1, 2017
Summary
This study introduces a novel BOTDR sensor using complementary coding and FFT for faster, more accurate distributed sensing. It achieves high resolution over 10 km, significantly reducing measurement time.
Area of Science:
- Optoelectronics
- Fiber Optic Sensing
- Signal Processing
Background:
- Distributed sensing systems are crucial for monitoring infrastructure.
- Traditional BOTDR systems face limitations in speed and accuracy.
- Optical amplifier noise can distort probe pulses, affecting measurement quality.
Purpose of the Study:
- To develop a high-performance BOTDR sensor with enhanced accuracy and reduced measurement time.
- To investigate the effectiveness of complementary coding and FFT in BOTDR.
- To suppress probe pulse distortion in BOTDR systems.
Main Methods:
- Implementation of a BOTDR sensor combining complementary coding and Fast Fourier Transform (FFT).
- Utilizing a pre-depletion two-wavelength probe pulse to mitigate EDFA-induced distortion.
- Experimental validation over 10 km of single-mode fiber.
Main Results:
- Achieved 2 m spatial resolution.
- Demonstrated a frequency uncertainty of 0.37 MHz, enabling precise temperature and strain measurements (∼0.37 °C / ∼7.4 με).
- Significantly reduced measurement time compared to classical frequency sweeping techniques.
Conclusions:
- The proposed BOTDR scheme offers a substantial improvement in performance for distributed sensing applications.
- Complementary coding and FFT integration enhance signal-to-noise ratio and measurement speed.
- The two-wavelength probe pulse effectively suppresses distortion, ensuring measurement accuracy.
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