Improvement of the measurement accuracy of distributed Brillouin sensing via radio frequency filtering

This paper presents and experimentally demonstrates a new approach for the noise reduction and measurement accuracy enhancement in Brillouin optical time domain analyzers (BOTDA) by applying low pass filtering to the detected radio frequency (RF) signal. The simulation and experimental results indicate that the noise level of the BOTDA traces is reduced by using RF filtering. The corresponding measurement accuracy improvement depends on the cut-off frequency of the employed low pass filter. RF filtering is more efficient than other post-processing methods since it overcomes the long processing time. However, the results also imply that RF filters with too low bandwidths distort the trace signals and lead to detection errors.

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