Systems and methods for detecting and tracking gun barrels using millimeter waves

• US 8,362,945 B2
• Filed: 10/04/2010
• Issued: 01/29/2013
• Est. Priority Date: 10/04/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Nguyen, Tien M., Wootan, John J.
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US12/897,660
• Publication Number:
  US 20120256779A1
• Time in Patent Office: 848 Days
• Field of Search: 342/27, 342/90, 342/189
• US Class Current: 342/90
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons

Abstract

Systems and methods for detecting and tracking a gun using millimeter waves are provided. In one embodiment, the invention relates to a method for detecting and tracking a gun using radio frequency waves at millimeter wavelengths, the method including storing empirical data, for up to N types of guns, including information indicative of a resonant frequency of a barrel of each of the N guns, generating pulse energy including at least one sequence of pulses at millimeter wave frequencies for each of the N guns, transmitting the pulse energy, receiving reflected pulse energy, filtering the reflected pulse energy to a preselected bandwidth for each of the N guns, determining a first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds a preselected threshold, determining a second maximum value among the first maximum values, and correlating a frequency of the second maximum value with the stored resonant frequencies of the N guns to identify a gun.

Claims

1. A method for detecting a gun using radio frequency waves, the method comprising:

storing empirical data, for up to N types of guns, including information indicative of a resonant frequency of a barrel of each of the N guns;

generating pulse energy comprising at least one sequence of pulses at millimeter wave frequencies for each of the N guns;

transmitting the pulse energy;

receiving reflected pulse energy;

filtering the reflected pulse energy to a preselected bandwidth for each of the N guns;

determining a first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds a preselected threshold;

determining a second maximum value among the first maximum values; and

correlating a frequency of the second maximum value with the stored resonant frequencies of the N guns to identify a gun.

2. The method of claim 1, further comprising tracking the identified gun using the stored resonant frequency for the identified gun.

3. The method of claim 2, wherein the tracking the identified gun using the stored resonant frequency for the identified gun comprises:

tracking the identified gun using the stored resonant frequency for the identified gun; and

generating pulse energy comprising a plurality of sequences of pulses at millimeter wave frequencies, wherein a period of each of the plurality of sequences of pulses corresponds to a resonant frequency of the identified gun.

4. The method of claim 1, wherein the generating pulse energy comprising the at least one sequence of pulses at millimeter wave frequencies for each of the N guns corresponding to the resonant frequency of the respective gun comprises:

generating pulse energy comprising the at least one sequence of pulses at millimeter wave frequencies for each of the N guns, wherein a period of each of the at least one sequence of pulses corresponds to a resonant frequency of a respective one of the N guns.

5. The method of claim 1, wherein the receiving the reflected pulse energy comprises:

receiving the reflected pulse energy; and

transforming the reflected pulse energy to an intermediate frequency.

6. The method of claim 1, wherein:

the filtering the reflected pulse energy to the preselected bandwidth for each of the N guns is performed using at least one digital signal processor;

the determining the first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds the preselected threshold is performed using the at least one digital signal processor;

the determining the second maximum value among the first maximum values is performed using the at least one digital signal processor; and

the correlating the frequency of the second maximum value with the stored resonant frequencies of the N guns to identify the gun is performed using the at least one digital signal processor.

7. The method of claim 1, wherein the reflected pulse energy is received from a gun among the N types of guns.

8. The method of claim 7, wherein the reflected pulse energy is received from the identified gun.

9. The method of claim 1, wherein the information indicative of the resonant frequency of the barrel of each of the N guns is determined using pulse energy generated at a preselected millimeter wave frequencies.

10. The method of claim 1, further comprising generating a warning when a gun has been identified within a preselected range based on an effective range corresponding to the gun.

11. A system for detecting a gun using radio frequency waves, the system comprising:

a storage circuitry configured to store empirical data, for up to N types of guns, including information indicative of a resonant frequency of a barrel of each of the N guns;

a generation circuitry configured to generate pulse energy comprising at least one sequence of pulses at millimeter wave frequencies for each of the N guns;

a transceiver configured to transmit the generated pulse energy and to receive reflected pulse energy; and

a processing circuitry configured to;

filter the reflected pulse energy to a preselected bandwidth for each of the N guns;

determine a first maximum value of the filtered reflected pulse energy in each of the preselected bandwidths that exceeds a preselected threshold;

determine a second maximum value among the first maximum values;

correlate a frequency of the second maximum value with the stored resonant frequencies of the N guns to identify a gun.

12. The system of claim 11, wherein the processing circuitry is further configured to track the identified gun using the stored resonant frequency for the identified gun.

13. The system of claim 12, wherein the processing circuitry is configured to generate pulse energy comprising a plurality of sequences of pulses at millimeter wave frequencies, wherein a period of the plurality of sequences of pulses corresponds to a resonant frequency of the identified gun.

14. The system of claim 11, wherein a period of the at least one sequence of pulses corresponds to a resonant frequency of a respective one of the N guns.

15. The system of claim 11, wherein the reflected pulse energy is received from a gun among the N types of guns.

16. The system of claim 15, wherein the reflected pulse energy is received from the identified gun.

17. The system of claim 11, wherein the information indicative of the resonant frequency of the barrel of each of the N guns is determined using energy generated at a preselected millimeter wave frequencies.

18. The system of claim 11, wherein the processing circuitry comprises at least one digital signal processor.

19. The system of claim 11, wherein the transceiver comprises a lightweight antenna configured to be mounted to a helmet of a person.

20. The system of claim 11, wherein the transceiver comprises an antenna configured to be mounted to a vehicle.

21. The system of claim 11, wherein the processing circuitry is configured to generate a warning when a gun has been identified within a preselected range based on an effective range corresponding to the gun.