High-Precision distributed fiber optic vibration positioning system with grating array

Abstract

The conventional distributed fiber optic positioning system (DFOPS) employing a single pulse working has a mutually constrained relationship between resolution and measurement distance, thereby imposing severe limitations on the advancement of DFOPS development. To solve this problem, we propose a strain and vibration event positioning system by employing correlated positioning techniques, pulse coding techniques, a broadband light source, and arrays of weakly reflective fiber gratings. To further improve the positioning accuracy of the system, the chip subdivision method and correlation prediction method are used to achieve centimeter-level localization accuracy in this study. In addition to correlation localization, we also propose a superposition signal decomposition model to achieve vibration event localization. Finally, to determine the most appropriate coding method for the system, a comparative analysis is performed to evaluate different coding methods in terms of coding gain, transmission time, and decoding complexity. We hope that the system and methods presented in this paper can serve as a valuable reference in the field of distributed fiber optic sensing with grating arrays for vibration detection.