相位检测型Φ-OTDR是一种高保真、高灵敏的分布式光纤振动传感技术，但由于受各类噪声以及解包裹过程中误差积累的影响，该技术对低频振动的检测误差较大，导致其应用受限。为解决该问题，本项目拟引入一种长时稳定性优异的高灵敏应力检测方案--波长扫描型COTDR，达成与前者的优势互补。为实现两种方案的有机融合，首先我们将利用统计方法与光频梳降低相位检测型Φ-OTDR误差，将其检测能力向低频区拓展，同时利用光频梳减少波长扫描型COTDR的扫描时间，将其检测能力向高频区拓展。其次，分析两者的检测误差与光源特性、探测脉冲参数以及振动信号幅频特性等关键影响因素的关系，得到误差模型。最后，利用已构建的误差模型完成新系统的参数设计，确定数据融合方案，获得兼容亚Hz至KHz频段的分布式光纤振动传感系统。本项目将扩展现有系统的可测量频率范围，提升分布式光纤振动传感系统的实用性，对该领域的发展产生积极的推动作用。

Phase-detection based Phase-sensitive Optical Time-Domain Reflectometry (Φ-OTDR) is a kind of distributed vibration sensing technology which can achieve the vibration measurement with high fidelity and sensitivity. However, the measurement accuracy of this technique is affected by the error accumulated in the unwrapping procedure, which degrades its performance in the low-frequency vibration sensing applications. In contrast to this, the wavelength-sweeping Coherent Optical Time-Domain Reflectometry (COTDR), which is another high sensitive strain detection method, has good long-term performance but limited in high frequency vibration detection. We combine these two methods together in this project. Firstly, the statistic method and optical frequency comb will be used to suppress the Φ-OTDR noises and enhance its low-frequency vibration performance. The optical frequency comb will also be utilized to reduce the wavelength-sweeping period and enhance the high-frequency vibration performance in COTDR. In addition, the error model of two schemes will be established based on the analysis of the laser parameters, the light pulse and the vibration. At last, an integrated distributed vibration sensing system will be established based on the error models, the parameter setting and data fusion scheme will be optimized, and the measurement of sub-Hz to KHz vibration will be achieved. This study will help to improve the detectable frequency region in real distributed vibration sensing applications.