A self-tracking phase retrieval algorithm used in distributed disturbance sensing

摘要

The phase-retrieval method with delayed calibration is widely used in fiber-optic sensing structures to extract the distributed vibration messages. Yet, the performance of this method is not satisfactory when sudden changes are introduced in sensing path, for the DC compensation is not a slow variable under this situation. To improve the adjustment of interferometric fiber-optic structure, a self-tracking phase retrieval method is proposed. In the novel algorithm, the static state is tracked by calibrating DC compensation value in each retrieval period. When tested in the real scene with a 20 km-long sensing fiber, the performance of the novel retrieval algorithm has been proved. Experimental results show that, compared with the conventional delayed calibration method, self-tracking algorithm brings a better accuracy and uniformity performance in intrusion location test and shows a better adaptability to the environment.