A method of achieving a fixed point position centimeter-level space resolution in long-distance distribution measurement

Abstract

The invention provides a method of achieving a fixed point position centimeter-level space resolution in long-distance distribution measurement. By using a sensing optical fiber with a special structure and applying a secondary sensor fiber whose Brillouin frequency shift is different from that of an adjacent optical fiber and whose length is the same as the length of a measured small-size position to a position having a specific and higher space resolution requirement and on the basis of a corresponding multimodal selection and fitting data processing method, the method aims to increase a space resolution for small size positions in long-distance optical fiber distribution measurement of a Brillouin optical time-domain analyzer, thus achieving high-space resolution monitoring of fixed point special small-size positions while achieving low-space resolution monitoring of common positions and further achieving temperature and stress monitoring of small-size positions only through the sensing optical fiber with a special structure without changing the structure and the detection pulse width of a conventional DPP-BOTDA instrument.

Description

technical field [0001] The invention relates to a method for realizing the centimeter-level spatial resolution of fixed-point positions in long-distance distribution measurement of a Brillouin optical time-domain analyzer by using frequency division multiplexing technology, and belongs to the field of optical technology. Background technique [0002] In recent years, with the rapid construction of public facilities such as large buildings and long-distance pipelines, and the large-scale coverage of power grids, there is an urgent need to study the safety and health monitoring of these facilities using optimized long-distance sensing systems. Brillouin optical time domain analysis technology is a kind of fiber optic sensor, which uses optical fiber as the sensor device and signal transmission channel, and has the remarkable advantage of realizing distributed measurement. However, the measurement distance and spatial resolution of Brillouin optical time domain analysis technol...

AI Technical Summary

Problems solved by technology

The spatial resolution of the differential pulse Brillouin optical time-domain analysis system (DPP-BOTDA) is determined by the detection pulse width (for example, the detection pulse width is 5ns, corresponding to a spatial resolution of 50cm), and events with a length lower than the spatial resolution will not be detected. be accurately detected

So far, the spatial resolution of long-distance optical fiber sensing that has been experimentally realized is mostly on the order of meters or sub-meters. However, in practical applications, the spatial resolution of meters can not meet the measurement requirements of some specific areas.

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