Abstract
The detecting and locating principle of the distributed optical fiber pipeline leakage detecting and prewarning system is proposed in this paper. In allusion to gross error which often occurred in the locating process, the optical polarization model of oil and gas pipeline fiber warning system is established in this paper, which is based on the equivalent Jones matrix of the single-mode optical fiber birefringence. By emulating the model, the reason of the gross error is the discrepancy of two signals, which means that the signals acquired by the photodetectors from the same vibroseis are not correlative. According to the theoretical model, the solution of using external polarization controller to change the polarization direction is put forward. It is proved by the experiment that the solution can solve the problem preferably and improve locating accuracy. Furthermore, theoretical guidance of the system improvement and the adjustment in optical structure can be provided based on the theoretical model.
