Systems and methods of communications for weapon detection systems

• US 7,719,428 B2
• Filed: 10/30/2007
• Issued: 05/18/2010
• Est. Priority Date: 01/24/2003
• Status: Expired due to Term

• Current Assignee: Shotspotter Incorporated
• Original Assignee: Shotspotter Incorporated
• Inventors: Fisher, Ken, Holmes, Fred, Baxter, Kevin
• Primary Examiner(s): Nguyen; Phung
• Application Number:
  US11/981,619
• Publication Number:
  US 20080267012A1
• Time in Patent Office: 931 Days
• Field of Search: 340/573.1, 340/426.19, 340/506, 340/539.13, 340/995.28, 340/691.6, 340/825.36, 340/521, 367/127
• US Class Current: 340/573.1
• CPC Class Codes: F41H 13/00 Means of attack or defence not otherwise provided for details of radar or sonar systems G01S7/00
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 5/22 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/28 takes precedence
• CPC Class Codes: Y10S 367/906 Airborne shock-wave detection

Abstract

Systems and methods are disclosed for data processing associated with acoustic events such as weapon fire. In one exemplary implementation, there is provided a method of processing communications associated with identifying or locating a weapon fire event. Moreover, the method may include processing communications from a plurality of sensors deployed across an area to be monitored, wherein the sensors are interconnected via a wireless network, processing signals communicated over the network from each sensor that detects the acoustic event, and determining a location of a source of the acoustic event as a function of time of arrival information and sensor location information. Other exemplary implementations may include using time of arrival data that is synchronous/universal among the sensors.

Claims

1. A method of processing communications associated with detection of acoustic events, the method comprising:

processing communications associated with sensors deployed across an area to be monitored, wherein the sensors are interconnected via a network operating, at least in part, using wireless communications that include accessing the network through a cellular telephone network, and wherein each sensor includes a clock source and a microphone for detecting an acoustic event;

processing signals communicated over the network from each sensor that detects the acoustic event, wherein the signals include times of arrival as to when the acoustic event was detected at the sensors, with each time of arrival being obtained from the clock source associated with the sensor that detected the acoustic event;

determining a location of a source of the acoustic event as a function of the time of arrival information and sensor location data; and

accumulating statistical information regarding the acoustic event from sensors registering the acoustic event and scoring the acoustic event as a function of the statistical information.

2. The method of claim 1 wherein the time of arrival information is measured at a peak of a beginning portion of an acoustic wave'"'"'s envelope as received at the sensors.

3. The method of claim 2 wherein the plurality of sensors comprises at least 3 sensors.

4. The method of claim 2 wherein the clock source is a clock having a time signal synchronizable with the clocks of the other sensors.

5. The method of claim 1 wherein the communications include information from the sensors transmitted through relays.

6. The method of claim 5 wherein the relays are transceivers that have no sensor or microphone elements.

7. The method of claim 1 wherein determination of the location of the source of the acoustic event includes processing relative times of arrival of acoustic waves from the acoustic event at the sensors.

8. The method of claim 7 wherein the clock source is a clock having a time signal synchronizable with the clocks of the other sensors.

9. The method of claim 7 wherein determining the location of the source of the acoustic event includes triangulating the location as a function of the sensor location information and time of arrival information.

10. The method of claim 7 wherein each sensor that detects the acoustic event transmits an identifier and a time of arrival of the event to a host processor for use in determining the location of the source of the acoustic event.

11. The method of claim 1 wherein the clock source is a clock having a time signal synchronizable with the clocks of the other sensors.

12. The method of claim 11 wherein determining the location of the source of the acoustic event includes triangulating the location as a function of the sensor location information and time of arrival information.

13. The method of claim 11 wherein each sensor that detects the acoustic event transmits an identifier and a time of arrival of the event to a host processor for use in determining the location of the source of the acoustic event.

14. The method of claim 11 wherein the time of arrival information is measured at a peak of a beginning portion of an acoustic wave'"'"'s envelope as received at the sensors.

15. The method of claim 1 wherein determining the location of the source of the acoustic event includes triangulating the location as a function of the sensor location information and time of arrival information.

16. The method of claim 1 wherein the plurality of sensors comprises at least 3 sensors.

17. The method of claim 1 wherein the data processed includes time of arrival information as to when the acoustic event was detected at the sensors, and further comprising enhancing accuracy of time values beyond accuracy of a clock source via a time mark function associated with a GPS.

18. The method of claim 1 wherein the clocks associated with the sensors are synchronized.

19. The method of claim 1 wherein the clocks associated with the sensors are synchronized via GPS time codes received at the sensors.

20. The method of claim 1 wherein time of arrival data associated with the acoustic event communicated from a plurality of the sensors to a processing component is communicated over a single channel without latency in connection with synchronization of each clock of the plurality of sensors with clocks of other sensors in a network.

21. The method of claim 1 wherein each sensor includes a GPS receiver that provides sensor location information for use in determination of the location of the source of the acoustic event.

22. The method of claim 1 wherein determination of the location of the source of the acoustic event includes iterative calculations of expanding spheres.

23. A method of processing communications associated with detection of acoustic events, the method comprising:

processing communications associated with sensors deployed across an area to be monitored, wherein the sensors are interconnected via a network operating, at least in part, using wireless communications that include accessing the network through a cellular telephone network, and wherein each sensor includes a clock source and a microphone for detecting an acoustic event;

processing signals communicated over the network from each sensor that detects the acoustic event, wherein the signals include times of arrival as to when the acoustic event was detected at the sensors, with each time of arrival being obtained from the clock source associated with the sensor that detected the acoustic event; and

determining a location of a source of the acoustic event as a function of the time of arrival information and sensor location data;

wherein determining the location of the source of the acoustic event includes solving six equations and six unknown variables.

24. The method of claim 23 wherein the clock source is a clock having a time signal synchronizable with the clocks of the other sensors.

25. The method of claim 23 wherein the clocks associated with the sensors are synchronized.

26. A method processing communications associated with detection of acoustic events, the method comprising:

processing communications associated with sensors deployed across an area to be monitored, wherein the sensors are interconnected via a network that includes the internet and operates, at least in part, using wireless communications, and wherein each sensor includes a clock source and a microphone for detecting an acoustic event;

processing data communicated over the network from each sensor that detects the acoustic event, wherein the data include times of arrival as to when the acoustic event was detected at the sensors, with each time of arrival being obtained from the clock source associated with the sensor that detected the acoustic event; and

determining a location of a source of the acoustic event as a function of the time of arrival information and sensor location data;

wherein determination of the location of the source of the acoustic event includes iterative calculations of expanding spheres.

27. The method of claim 26 wherein determining the location of the source of the acoustic event includes triangulating the location as a function of the sensor location information and time of arrival information.

28. The method of claim 26 wherein the clock source is a clock having a time signal synchronizable with the clocks of the other sensors.