CA-3043239-C - ACOUSTIC METHOD AND SYSTEM FOR PROVIDING DIGITAL DATA

Abstract

An acoustic system and method is disclosed for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area. The system includes an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network. An optical signal detector arrangement receives, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres. A processing unit demodulates acoustic data from the optical signals, processes the acoustic data and classifies it in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and a storage unit stores the datasets in parallel with raw acoustic or optical data which is time and location stamped so that it can be retrieved for further processing.

Inventors

• Mark Andrew Englund

Assignees

• Mark Andrew Englund

Dates

Publication Date

20260505

Application Date

20171110

Priority Date

20161110

Claims (18)

1. 35 Claims 1. An acoustic method of providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area, the method including the steps of: repeatedly transmitting, at multiple instants, interrogating optical signals into one or more of a plurality of optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network, wherein the installed fibre-optic communications network includes the plurality of optical fibres, and segments of the one or more of the plurality of optical fibres create a plurality of virtual dedicated sensing networks; receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of the plurality of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple targets within the observation period; demodulating acoustic data from the optical signals; processing the acoustic data and classifying the processed acoustic data in accordance with target classes or types to generate a plurality of datasets including classification, temporal and location-related data; storing the datasets in parallel with raw acoustic data which is time and location stamped so that it can be retrieved for further processing and matched with the corresponding datasets to provide both real time and historic data; and monitoring a plurality of different footprints in the geographic area, each footprint comprising at least one virtual dedicated sensing network.
2. 2. The method of claim 1, wherein the acoustic data is classified by correlating it with acoustic signatures associated with each of the target classes or types, wherein the method includes generating the acoustic signatures of a number of sound producing targets.
3. 3. The method of claim 2 further comprising the step of classifying the sound producing targets as symbols representative of the sound producing targets and storing the symbols as part of the datasets in a digital symbol index. 36
4. 4. The method of claim 2, further comprising: generating a higher order symbol index database including dynamic symbol data associated with velocity and direction, and with alert criteria.
5. 5. The method of claim 2, further comprising: generating alert criteria associated with the respective acoustic signatures, and triggering an alarm or warning in the event of the alert criteria being triggered, wherein the alert criteria are generated using a semantics engine to assess a threat or alert level associated with a target, and the alarm is triggered in the event of the threat or alert level exceeding a threshold.
6. 6. The method of claim 1, further comprising: receiving a search request directed towards one or more of the classification, temporal or location-related data, and using the data in conjunction with a GIS overlay, including representing target classes or types as symbols.
7. 7. The method of claim 1, wherein the one or more optical fibres include one or more unlit optical fibres or unused spectral channels in the installed urban or metropolitan fibre-optic communications network, and the fibre-optic communications network is a high density public telecommunications network.
8. 8. The method of claim 1, further including processing or representing the datasets together with surveillance data obtained from at least one non-acoustic sensing system.
9. 9. The method of claim 1, further comprising storing raw optical data in parallel for subsequent retrieval and processing.
10. 10. The method of claim 9, wherein beam forming techniques are used on at least one of the retrieved and processed raw optical data and the demodulated acoustic data. 37
11. 11. The method of claim 1, further comprising: obtaining at least location related data associated with each footprint and processing this data with that of the generated datasets to provide dedicated datasets associated with each footprint, the location related data corresponding to the virtual dedicated sensing network.
12. 12. The method of claim 11, wherein the entity or subscriber has at least one premises in the geographic area and the virtual dedicated sensing network coincides with critical infrastructure around the premises requiring monitoring and protection including at least one of power lines, water mains, telecommunications lines and gas mains.
13. 13. An acoustic method of providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area, the method including the steps of: repeatedly transmitting, at multiple instants, interrogating optical signals into one or more of a plurality of optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network, wherein the installed fibre-optic communications network includes the plurality of optical fibres, and segments of the one or more of the plurality of optical fibres create a plurality of virtual dedicated sensing networks; receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of the plurality of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple targets within the observation period; converting the optical signals to optical data, and storing the optical data, the optical data including temporal and location related data; receiving a search request including temporal and location related filters or parameters, and retrieving the optical data based on said parameters; processing the optical data into acoustic data; and 38 monitoring a plurality of different footprints in the geographic area, each footprint comprising at least one virtual dedicated sensing network.
14. 14. The method of claim 13, further comprising: processing the acoustic data and classifying it in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and storing the datasets.
15. 15. The method of claim 13, wherein the optical data is processed into acoustic data at a resolution based on the temporal and location based parameters, the processing including retrieving the acoustic data at a desired resolution for beam forming at a desired location.
16. 16. An acoustic system for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area, the system including: an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into one or more of a plurality of optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network, wherein the installed fibre-optic communications network includes the plurality of optical fibres, and segments of the one or more of plurality of the optical fibres create a plurality of virtual dedicated sensing networks; an optical signal detector arrangement for receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of the plurality of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple targets within the observation period; a processing unit for demodulating acoustic data from the optical signals, processing the acoustic data and classifying the acoustic data in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data; 39 a storage unit for storing the datasets in parallel with raw acoustic data which is time and location stamped so that it can be retrieved for further processing and matched with the corresponding datasets to provide both real time and historic data; and wherein the processing unit is configured to monitor a plurality of different footprints in the geographic area, each footprint comprising at least one virtual dedicated sensing network.
17. 17. The system of claim 16, wherein the processing unit is configured to obtain at least location related data associated with each footprint and process this data with that of the generated datasets to provide dedicated datasets associated with each footprint, the location related data corresponding to the virtual dedicated sensing network.
18. 18. An acoustic system for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area, the system including: an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into one or more of a plurality of optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network, wherein the installed fibre-optic communications network includes the plurality of optical fibres, and segments of the one or more of the plurality of optical fibres create a plurality of virtual dedicated sensing networks; an optical signal detector arrangement for receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of the plurality of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple targets within the observation period; an A/D converter for converting the optical signals to optical data; a storage unit for storing the optical data, the optical data including temporal and location related data; 40 a communications interface and processor for receiving a search request including temporal and location related filters or parameters, and retrieving the optical data based on said parameters for processing it into acoustic data; and a processing unit configured to demodulate acoustic data from the optical signals, process the acoustic data, and classify the acoustic data in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and store the datasets in the storage unit, wherein the processing unit is configured to process the optical data into acoustic data at a resolution based on the temporal and location based parameters, the processing unit being arranged to retrieve the acoustic data at a desired resolution for beam forming at a desired location; wherein the processing unit is configured to monitor a plurality of different footprints in the geographic area, each footprint comprising at least one virtual dedicated sensing network.

Description

1 ACOUSTIC METHOD AND SYSTEM FOR PROVIDING DIGITAL DATA Field of the invention The present disclosure generally relates to an acoustic method and system for providing digital data. In particular, the present disclosure relates to an acoustic 5 method and system for providing digital data collected over a geographical area, such as a city or an urban area. Background of the invention Wide area surveillance refers to real-time close observation in a geographical area, such as a city or an urban area. Wide area surveillance can be useful for 10 monitoring of targets, such as vehicle and pedestrian traffic, and for law enforcement purposes, such as monitoring social disturbances or criminal activity. Wide area surveillance may be used in conjunction with a geographic information systems (GIS) overlay to assist in surveillance and monitoring across a mapped region. Known wide area surveillance systems include those employing visual means, 15 which collect visual information for surveillance. For example, closed-circuit television (CCTV) cameras have been used to monitor city streets. Each CCTV camera can provide one localised view of a streetscape at any one time with a depth of field of view determined by the optics of the CCTV camera. In case of a system with multiple CCTV cameras, the blind spots or the visually least clear spots in the city are 20 potentially locations mid-way between CCTV cameras or outside a CCTV camera's field of view. As another example, street views captured by a camera system mounting on a moving vehicle can provide visibility of some of these blind spots, but the street view images are static and impractical to be regularly updated for live monitoring. As yet another example, satellite imagery can provide a city-wide bird's 25 eye view of objects that are in the satellite's unobstructed line-of-sight. Targets or events that are visually obstructed (e.g. underground, under thick clouds, within a 2 building or under bridges or flyovers) would therefore lack surveillance visibility from satellite images, which are also static. Other known wide area surveillance systems include those employing radio means. For example, cellular signals from mobile devices carried by users may be 5 used to provide surveillance information on, for instance, the number of people in proximity of, and their locations from, a cell tower by determining the number of cellular connections and signal strength or signal information. The surveillance information obtainable from cellular signals may not be a reliable representation of the true number of people and their approximate locations with respect to a cell tower. 10 A person in the area may well carry none or multiple mobile devices or have their mobile device switched off. Further, mobile device signals vary in strength across different devices and some may be penetrating or reflected off buildings such that the signal strength becomes an unreliable indicator of distance. Not every person would be carrying a single, transmitting mobile device with consistent signal power in radio 15 line-of-sight of a cell tower at all times. In addition mobile devices are not reliably able to convey classification data about the object they are associated with, in that they may be associated with more than one object. A further example is in the form of arrays of inductive loops deployed at traffic light intersections for detection of vehicles on roads. This system can only 20 detect metal vehicles and as such cannot detect pedestrians and other biologics, and can only detect across limited zones. Lidar looking down on city areas has similar limitations as a satellite as it is line of sight only and will have blind spots. It is also non trivial to detect and classify the presence of distinct objects from the measurement field (eg cars, pedestrians, 25 bicycles, trucks etc). Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant and/or combined with other pieces 30 of prior art by a person skilled in the art. 3 Summary of the invention In one aspect there is provided an acoustic method of providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area, the method including the steps of: repeatedly transmitting, at 5 multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibreoptic communications network; receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres, the scattering influenced 10 by acoustic disturbances caused b