System and method for precision acoustic event detection

• US 20100278013A1
• Filed: 02/11/2010
• Published: 11/04/2010
• Est. Priority Date: 01/20/2005
• Status: Abandoned Application

• Current Assignee: Shotspotter Incorporated
• Original Assignee: Shotspotter Incorporated
• Inventors: Baxter, Kevin, Fisher, Ken, Holmes, Fred
• Application Number:
  US12/658,771
• Publication Number:
  US 20100278013A1
• Time in Patent Office: Days
• US Class Current: 367/129
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• 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

Abstract

Systems and methods of providing precision locations for sensors which make up an array of sensors in a gunshot detection system. Consistent with some exemplary implementations, sensors may employ a commercial GPS which reports a sensor position or a group of pseudoranges to GPS satellites. A server may collect differential information from a differential node and, in one exemplary implementation, may calculate a precision position for each sensor by adjusting the reported position or pseudoranges with the differential information. In other exemplary implementations, differential information may be sent from the host to individual sensors which calculate their own precision positions. Exemplary differential information may include latitude and longitude corrections, pseudorange corrections, ionospheric delay, GPS satellite clock drift, or other corrective term which will improve the accuracy of a sensor position.

Claims

1. A gunshot detection system comprising:

an array of sensors, at least one sensor of said array of sensors comprises;

a microphone for receiving acoustic signals;

a processor for processing received acoustic signals to detect an acoustic event;

a first commercial GPS receiver for determining a sensor position; and

a first network interface;

a differential node at a known location, said differential node comprising;

a second GPS receiver for determining a GPS position; and

a second network interface; and

a server comprising;

a CPU; and

a third network interface in communication with said first and second network interfaces such that said one or more sensors can communicate with said host node and said differential node can communicate with said host node, wherein said at least one sensor communicates said sensor position to said server and said differential node communicates said GPS position to said server and wherein when said acoustic event is detected, said at least one sensor communicates event information to said server and said server computes a precision position for said at least one sensor based on said sensor position and said GPS position.

2. The gunshot detection system of claim 1 wherein said server and said differential node are collocated.

3. The gunshot detection system of claim 1 wherein said known location is a surveyed location.

4. The gunshot detection system of claim 1 wherein said second GPS comprises a military GPS and said known position is provided by said military GPS.

5. The gunshot detection system of claim 1 wherein said server is configured to receive WAAS information from either said differential node or said at least one sensor and, upon receiving said WAAS information, said server communicates said WAAS information through said third network interface.

6. The gunshot detection system of claim 5 wherein said differential node is a second sensor of said array of sensors.

7. The gunshot detection system of claim 1 wherein said sensor position includes a plurality of pseudoranges.

8. The gunshot detection system of claim 1 wherein said GPS position includes a plurality of pseudoranges.

9. In a system having an array of commercial GPS based sensors, a method for determining a precision position for at least one sensor of said sensor array including the steps of:

(a) receiving a sensor position from said at least one sensor;

(b) receiving a GPS position from a commercial GPS at a known location;

(c) calculating a position difference between said known location and said GPS location; and

(d) calculating a precision position by adjusting said sensor position with said position difference.

10. The method for determining a precision position of claim 9 wherein step (b) includes the substeps of:

(b)(i) receiving a first position from a military GPS to determine a known location; and

(b)(ii) receiving a GPS position from a commercial GPS at said known location.

11. The method for determining a precision position of claim 9 wherein step (b) includes the substeps of:

(b)(i) surveying a first position to determine a known location; and

(b)(ii) receiving a GPS position from a commercial GPS at said known location.

12. A method for determining a precision position for at least one sensor of a sensor array wherein WAAS information is available from a commercial GPS located proximate said sensor array, the method including the steps of:

(a) receiving WAAS information from said commercial GPS;

(b) transmitting said WAAS information to said at least one sensor;

(c) receiving said WAAS information at said at least one sensor;

(d) calculating a precision position for said at least one sensor by adjusting a local position provided by a local GPS at said at least one sensor with said WAAS information.

13-55. -55. (canceled)