A distributed pressure sensor is proposed and designed for dynamic pressure measurement by using frequency-agile fast Brillouin optical time-domain analysis (BOTDA). A double coated single-mode fiber (SMF) is used as the sensing fiber because of its 1500- $\mu \text{m}$ thickness outer coating that can significantly improve the dependence of the Brillouin frequency shift on pressure. Then, the frequency-agile technique is used to generate frequency-agile pump pulse in BOTDA system so that a fast Brillouin gain spectrum distribution measurement can be achieved. An injection locked scheme is used as both optical filter and optical amplifier to improve the measurement accuracy. As a result, the static pressure sensitivity of the double coated fiber is −3.46 MHz/MPa with the pressure ranging from 0 to 30 MPa. Subsequently, a large dynamic range pressure measurement is performed with a sampling rate of 33.3 kHz and maximum sensing distance of 25 m. Furthermore, it is proved that the uncertainty of dynamic pressure measurement system is 0.03 MPa.

中文翻译：

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使用频率捷变快速 BOTDA 的动态分布式压力测量

利用频率捷变快速布里渊光学时域分析（BOTDA），提出并设计了一种分布式压力传感器，用于动态压力测量。使用双涂层单模光纤 (SMF) 作为传感光纤，因为它具有 1500- $\mu \text{m}$ 厚度的外涂层，可以显着改善布里渊频移对压力的依赖性。然后，利用频率捷变技术在BOTDA系统中产生频率捷变泵浦脉冲，从而实现快速布里渊增益谱分布测量。注入锁定方案用作光学滤波器和光学放大器以提高测量精度。结果，双涂层光纤的静压灵敏度为-3.46 MHz/MPa，压力范围为0到30 MPa。随后，以 33.3 kHz 的采样率和 25 m 的最大感应距离执行大动态范围压力测量。进一步证明，动态压力测量系统的不确定度为0.03 MPa。