Alerting system for a facility

• US 7,957,225 B2
• Filed: 12/21/2007
• Issued: 06/07/2011
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Textron Systems Corporation (Textron Inc)
• Original Assignee: Textron Systems Corporation (Textron Inc)
• Inventors: Steadman, Robert L.
• Primary Examiner(s): PIHULIC, DANIEL T
• Application Number:
  US11/962,970
• Publication Number:
  US 20100284249A1
• Time in Patent Office: 1,264 Days
• Field of Search: 367/136, 367/118, 367/124, 367/127, 367/129
• US Class Current: 367/124
• CPC Class Codes: G01S 5/20 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 7/52001 Auxiliary means for detecting or identifying sonar signals or the like, e.g. sonar jamming signals
• CPC Class Codes: G08B 13/1672 using sonic detecting means, e.g. a microphone operating in the audio frequency range
• CPC Class Codes: G08B 13/2491 Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field

Abstract

A surveillance system is configured to detect a rotary-wing aircraft approaching a fixed facility and provide a warning upon detection. The system includes acoustic processing nodes that receive acoustic signals from the environment surrounding the fixed facility. As the nodes receive the acoustic signals, the nodes perform a spectral analysis of the signals to detect if the source of the acoustic signals is a rotary-wing aircraft. Additionally, based upon the acoustic signals, the nodes detect an altitude of the rotary-wing aircraft and a distance between the rotary-wing aircraft and the fixed facility. In the case where the system identifies the rotary-wing aircraft as encroaching a predefined geographical area outside of the facility, based upon the altitude and distance between the rotary-wing aircraft and the facility, the system generates a warning to allow security forces to intercept the rotary-wing aircraft prior to its arrival at the facility.

Claims

1. A method for providing a warning for a facility, comprising:

receiving an acoustic signal at a set of nodes disposed at the facility;

classifying a source of the acoustic signal based upon a spectral analysis of a frequency-based domain signature of the acoustic signal;

detecting a bearing of the source of the acoustic signal and an elevation of the source of the acoustic signal relative to each node of the set of nodes;

transmitting, from a first node of the set of nodes to a second node of the set of nodes, the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the first node;

detecting a distance of the source of the acoustic signal from the facility and an altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal; and

generating the warning (i) when the source of the acoustic signal is classified as a rotary-wing aircraft and (ii) when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within a defined geographical zone relative to the facility;

wherein detecting the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal comprises detecting, by the second node, the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the first node and based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the second node.

2. The method of claim 1, wherein detecting the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal comprises triangulating a position of the source of the acoustic signal based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to each node of the set of nodes.

3. The method of claim 1, wherein each node carries a plurality of acoustic detectors and wherein:

receiving the acoustic signal at a set of nodes disposed at the facility comprises receiving the acoustic signal by a plurality of acoustic sensors carried by each node of the set of nodes;

detecting the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to each node of the set of nodes comprises detecting the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to each node of the set of nodes based upon a strength of the acoustic signal relative to the plurality of acoustic sensors carried by each node of the set of nodes.

4. The method of claim 1, wherein detecting a distance of the source of the acoustic signal from the facility and an altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal further comprises detecting a velocity of the source of the acoustic signal relative to the facility.

5. The method of claim 1, comprising:

defining an exclusionary zone as part of the defined geographical zone relative to the facility; and

withholding the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the exclusionary area of the defined geographical zone relative to the facility.

6. The method of claim 1, wherein classifying the source of the acoustic signal based upon the spectral analysis of the frequency-based domain signature of the acoustic signal comprises:

converting the acoustic signal from a time-based domain signal to a frequency-based domain signal;

comparing a set of peak harmonics of the frequency-based domain signal with a set of peak harmonics that characterize an acoustic signal generated by a rotary-wing aircraft; and

classifying the source of the acoustic signal as a rotary-wing aircraft when the set of peak harmonics of the frequency-based domain signal corresponds with the set of peak harmonics that characterize the acoustic signal generated by a rotary-wing aircraft.

13. The method of claim 1, wherein each node of the set of nodes comprises a set of microphones, a controller disposed in electrical communication with the set of microphones, the controller having a transceiver configured to support communications with the remaining nodes of the set of nodes.

14. The method of claim 5, wherein:

defining the exclusionary zone as part of the defined geographical zone relative to the facility comprises defining the exclusionary zone as an overlapping zone common to the defined geographical zone relative to the facility and to a defined geographical zone of a second facility disposed in proximity to the facility; and

withholding the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the exclusionary area of the defined geographical zone relative to the facility comprises withholding the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the overlapping zone common to the defined geographical zone relative to the facility and to the defined geographical zone of the second facility disposed in proximity to the facility.

15. The method of claim 1, comprising:

defining a first geographic zone relative to the facility;

defining a second geographic zone relative to the facility, the second zone included within the first zone; and

wherein generating the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within a defined geographical zone relative to the facility comprises;

generating a first warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the first defined geographical zone relative to the facility; and

generating a second warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the second defined geographical zone relative to the facility, the second warning being distinct from the first warning and the second warning indicating an increased risk of threat to the facility, relative to the first warning.

7. A system for cuing a warning signal for a facility, comprising:

a set of nodes disposed at the facility, each node of the set of nodes carrying a plurality of audio sensors, each node is configured to detect a bearing of the source of an acoustic signal and an elevation of the source of the acoustic signal, the set of nodes configured to;

receive the acoustic signal from the corresponding plurality of audio sensors;

classify a source of the acoustic signal based upon a spectral analysis of a frequency-based domain signature of the acoustic signal;

detect a distance of the source of the acoustic signal from the facility and an altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal; and

generate the warning (i) when the source of the acoustic signal is classified as a rotary-wing aircraft and (ii) when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within a defined geographical zone relative to the facility;

wherein the set of nodes comprises a first set of nodes and a second set of nodes;

the first node of the set of nodes configured to transmit to the second node of the set of nodes, the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the first node; and

when detecting the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal, the second node is configured to detect the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the first node and based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to the second node.

8. The system of claim 7, wherein when detecting the distance of the source of the acoustic signal from the facility and the altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal each node is configured to triangulate a position of the source of the acoustic signal based upon the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal detected by each node of the set of nodes.

9. The system of claim 7, wherein:

when receiving the acoustic signal at a set of nodes disposed at the facility each node is configured to receive the acoustic signal by a plurality of acoustic sensors carried by each node of the set of nodes; and

when detecting the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to each node of the set of nodes is configured to detect the bearing of the source of the acoustic signal and the elevation of the source of the acoustic signal relative to each node of the set of nodes based upon a strength of the acoustic signal relative to the plurality of acoustic sensors.

10. The system of claim 7, wherein when detecting a distance of the source of the acoustic signal from the facility and an altitude of the source of the acoustic signal relative to the facility based upon the acoustic signal each node of the set of nodes is configured to detect a velocity of the source of the acoustic signal relative to the facility.

11. The system of claim 7, wherein each node is configured to:

define an exclusionary zone as part of the defined geographical zone relative to the facility; and

withhold the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the exclusionary area of the defined geographical zone relative to the facility.

12. The system of claim 7, wherein when classifying the source of the acoustic signal based upon the spectral analysis of the frequency-based domain signature of the acoustic signal, each node of the set of nodes is configured to:

convert the acoustic signal from a time-based domain signal to a frequency-based domain signal;

compare a set of peak harmonics of the frequency-based domain signal with a set of peak harmonics that characterize an acoustic signal generated by a rotary-wing aircraft; and

classify the source of the acoustic signal as a rotary-wing aircraft when the set of peak harmonics of the frequency-based domain signal corresponds with the set of peak harmonics that characterize the acoustic signal generated by a rotary-wing aircraft.

16. The system of claim 7, wherein each node of the set of nodes comprises a set of microphones, a controller disposed in electrical communication with the set of microphones, the controller having a transceiver configured to support communications with the remaining nodes of the set of nodes.

17. The system of claim 11, wherein:

when defining the exclusionary zone as part of the defined geographical zone relative to the facility, the set of nodes is configured to define the exclusionary zone as an overlapping zone common to the defined geographical zone relative to the facility and to a defined geographical zone of a second facility disposed in proximity to the facility; and

when withholding the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the exclusionary area of the defined geographical zone relative to the facility, the set of nodes is configured to withhold the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the overlapping zone common to the defined geographical zone relative to the facility and to the defined geographical zone of the second facility disposed in proximity to the facility.

18. The system of claim 7, wherein the set of nodes is configured to:

define a first geographic zone relative to the facility;

define a second geographic zone relative to the facility, the second zone included within the first zone; and

when generating the warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within a defined geographical zone relative to the facility comprises;

generate a first warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the first defined geographical zone relative to the facility; and

generate a second warning when the detected distance of the source of the acoustic signal from the facility and the detected altitude of the source of the acoustic signal relative to the facility falls within the second defined geographical zone relative to the facility, the second warning being distinct from the first warning and the second warning indicating an increased risk of threat to the facility, relative to the first warning.