Firearm Threat Detection, Classification, and Location Using Wideband Radar

• US 20120038505A1
• Filed: 10/25/2011
• Published: 02/16/2012
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Flex Force Enterprises, LLC
• Original Assignee: Flex Force Enterprises, LLC
• Inventors: Hyman, Daniel J., Sullivan, Jacob Ryan
• Granted Patent: US 8,610,622 B2
• Time in Patent Office: Days
• US Class Current: 342/90
• CPC Class Codes: F41G 3/14 Indirect aiming means
• CPC Class Codes: F41G 3/147 based on detection of a firing weapon
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26

Abstract

An aimed or aiming firearm can be detected before it is able to shoot. Wideband radar signals can be used to identify the barrel of a firearm when the radar antenna and barrel are aiming at or near each other. Signal processing correlates reflected signals to the characteristics of specific firearms of interest, and alerts the user when someone is pointing such a firearm at them. Modern wideband radar systems with fast signal processing speed can enable real-time detection of firearm threats in crowded and cluttered areas before they shoot, which has never before been possible. Related systems, apparatus, methods, and articles are also described.

Claims

1. A method comprising:

transmitting radio frequency signals towards a weapon, the transmitted frequency signals covering a range of frequencies propagated down at least one type of weapon barrel;

receiving radio frequency signals reflected from the weapon;

comparing the received radio frequency signals to a library of radio frequency signatures or patterns for a plurality of different objects; and

providing data characterizing the weapon based on the comparison.

2. A method as in claim 1, wherein the radio frequency signatures or patterns characterize variances in phase and amplitude with both time and frequency due to radio frequency characteristics of the weapon.

3. A method as in claim 1, wherein the radio frequency signatures or patterns are derived, at least in part, empirically.

4. A method as in claim 1, wherein at least a portion of the radio frequency signatures or patterns are derived, at least in part, theoretically.

5. A method as in claim 1 further comprising:

estimating a distance to the weapon; and

modifying the received radio frequency signals based on a factor associated with the estimated distance;

wherein the comparing compares the modified received radio frequency signals to the radio frequency signatures or patterns for a plurality of different objects.

6. A method as in claim 1, wherein the radio frequency signals are radar signals.

7. A method as in claim 1, wherein the transmitted radio frequency signals were generated with directivity greater than 10.

8. A method as in claim 1, wherein the radio frequency signatures or patterns each characterize variances in phase and amplitude with both time and frequency due to reflections associated with specific waveguide characteristics for a corresponding weapon barrel.

9. A method as in claim 1, wherein the weapon is a handheld firearm.

10. A method as in claim 9, wherein the firearm is selected from a group consisting of:

5.56 mm rifles, 7.62 mm rifles, and 0.50 caliber rifles.

11. A method as in claim 1, wherein the data characterizing the weapon identifies the location of the firearm.

12. A method as in claim 1, wherein the data characterizing the weapon indicates a range to the firearm.

13. A method as in claim 1, further comprising:

processing the received radio frequency signals to resolve and identify reflections associated with radiating antenna characteristics of a weapon.

14. A method as in claim 1, wherein an antenna for transmitting and/or receiving the radio frequency signals has a directivity characteristic between 100 and 100,000.

15. A method as in claim 1, wherein the library comprises data characterizing a fixed length of lossy transmission lines, the transmission line characterizing a steel circular waveguide of a firearm barrel and the fixed length characterizing a distance from a mouth of the firearm barrel to a chambered round.

16. A method comprising:

transmitting radio frequency signals towards a zone of interest containing a plurality of weapons from a first location;

receiving radio frequency signals reflected from the zone of interest;

comparing the received radio frequency signals to a library of radio frequency signatures or patterns for a plurality of different weapons to identify weapons in the zone of interest;

determining using the received radio frequency signals whether the identified weapons in the zone of interest are aimed at the first location or whether they are aimed at a different location;

providing data characterizing at least one weapon in the zone of interest.

17. A method as in claim 16, wherein the radio frequency signatures or patterns are derived, at least in part, empirically.

18. A method as in claim 16, wherein the radio frequency signatures or patterns are derived, at least in part, theoretically.

19. A weapon threat detection system comprising:

an outbound antenna apparatus that transmits an outbound radio frequency signal toward a potential threat;

an inbound antenna that receives an inbound reflected radio frequency signal from the potential threat; and

at least one processor coupled to a data store, the data store storing a library of empirically or theoretically derived radar signatures or patterns for a plurality of different weapons;

wherein the processor is configured to analyze the inbound reflected radar signals to determine whether the potential threat includes a weapon barrel pointed in the direction of the receiving antenna apparatus and to identify the weapon by comparing the inbound reflected radio frequency signal to the library of empirically or theoretically derived radar signatures or patterns.

20. A system as in claim 19, wherein the weapon is a handheld firearm.

21. A system as in claim 19 wherein the processor initiates notification to a user of the potential threat.

22. A system as in claim 21, wherein the processor initiates notification of a user of a location of the potential threat in relation to the inbound antenna.