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.

Aspects of the present disclosure describe systems, methods, and structures for distributed temperature sensing that employ joint wavelet denoising to achieve desirable signal-to-noise ratio(s) over extended sensor fiber distances.

The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

Aspects of the present disclosure describe a computer implemented method for the transfer of sensor data on dynamic software defined network (SDN) controlled optical network.

The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

Embodiments of the invention provide an improved optical fiber distributed acoustic sensor system that makes use of an optical fiber having reflector portions distributed along its length in at least a first portion. In particular, in order to increase the spatial resolution of the sensor system to the maximum, the reflector portions are positioned along the fiber separated by a distance that is equivalent to twice the distance an optical pulse travels along the fiber in a single sampling period of the data acquisition opto-electronics within the sensor system. As such, no oversampling of the reflections of the optical pulses from the reflector portions is undertaken, which means that it is important that the sampling points for data acquisition in the sensor system are aligned with the reflections that arrive at the sensor system from along the sensing fiber. In order to ensure such alignment, adaptive delay componentry may be used to adaptively align the reflected optical signals (or their electrical analogues) with the sampling points. Alternatively, control over the sampling points can also be undertaken to re-synchronise the sampling points with the returning reflections. In addition, in order to allow higher speed sampling to be undertaken, reflection equalisation componentry may also be used to reduce the dynamic range of the returning reflections.

A method of determining perturbation of a grating formed in an optical fiber, comprises: modulating and transmitting a light beam through the optical fiber, measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of the grating based on the phase shift(s).

The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

A distributed fiber-optic acoustic sensing system and a signal processing method. The distributed fiber-optic acoustic sensing system is based on a high spatial resolution distributed fiber-optic acoustic sensor. The interval between adjacent sensing units is centimeter or millimeter level. Through specific digital signal processing, signal enhancement can be realized, noise in the system and environment are suppressed, at the same time, problems such as interference fading is solved, and the sensor signal-to-noise ratio of subunits can be increased by two to three orders of magnitude. Each subunit can serve as an independent high-sensitivity sensor for sensing. The multiple subunits can form one or more new sensor arrays. The azimuth estimation and spatial orientation of signal sources can be realized by the array signal processing method.

A system may include a first sensor of a first type and a second sensor of a second different type and having a detector. A field of view of the second sensor may be formed by a plurality of regions of interest (ROIs) defined by the detector. Control circuitry of the system may be configured to perform operations including obtaining, from the first sensor, first sensor data representing an environment, and determining, based on the first sensor data, information associated with a feature of interest within the environment. The operations may also include determining, based on the information, a particular ROI that corresponds to an expected position of the feature at a later time, obtaining a plurality of ROI sensor data from the particular ROI instead of obtaining full-resolution sensor data, and analyzing the plurality of ROI sensor data to determine one or more attributes of the feature.