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Brillouin optical time domain analysis (BOTDA) sensor systems play a pivotal role in distributed sensing, which enable precise measurements of strain and temperature across extensive fiber lengths. Nonetheless, challenges emerge as distances grow due to signal attenuation and noise interference resulting in measurement errors. This research offers a comprehensive strategy to extend the sensing range of BOTDA systems beyond tens of kilometers while maintaining high spatial resolutions. Such enhanced sensing is realized through hybrid system that employs the integration of distributed Raman amplification, and inline amplification using erbium-doped fiber amplifiers (EDFA), as well as advanced noise reduction techniques. By optimizing power levels for the Brillouin pump and probe signals, as well as for Raman pump, hybrid BOTDA system ensures the robustness of Brillouin scattering signals, effectively countering attenuation-induced losses. Distributed amplification not only conquers attenuation but also suppresses nonlinear effects that could undermine measurement accuracy. Additionally, enhancing weak Brillouin signals by strategically placing EDFAs at optimal fiber locations keeps sensor sensitivity high. Leveraging inherent redundancy in measured data as a function of frequency and fiber distance, the non-local means (NLM) filter removes noise while preserving essential physical information. This approach proves particularly advantageous in BOTDA systems, where accurate measurement of Brillouin scattering signals is paramount for long-range sensing with high spatial resolutions. In summary, this research has shown a holistic exploration of extending BOTDA’s distance sensing capabilities up to 150km with spatial resolutions of 8 meters, and Brillouin frequency shift error of 1MHz.
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