Method and system for distributed fibre optic sensing

Abstract

Described herein is a method and system for distributed fibre optic sensing in particular across multiple fibre optic ports with multiple corresponding fibre optic paths. In general, the disclosed method and system includes the steps of (a) repeatedly transmitting a train of optical signals through a fibre optic network including a plurality of optical fibres distributed across a geographic area using at least one optical signal transmitter, (b) sequentially distributing optical signals in the train through the plurality of optical fibres via corresponding optical fibre ports using an optical switching arrangement, (c) receiving backscattered optical signals from the plurality of optical fibres, the backscattered optical signals being influenced by disturbances that induce fibre optic sensing signals, including low frequency weight-induced disturbances, (d) demodulating data from the backscattered optical signals, and processing the data to identify at least some of the low-frequency weight-induced disturbances, and/or (e) sensing the backscattered optical signals in a reduced frequency range, thereby reducing the corresponding required sampling rate and increasing the predetermined multiplex or switching ratio or the number of optical fibre ports serviced per optical signal transmitter/receiver. The disclosed method and system may be useful to provide efficient usage of hardware resources. The disclosed method and system may also be useful to detect low frequency weight-induced disturbances for object tracking against high noise clutter in the higher frequency signal bands.

Dependencies are inferred from the claim text.