Method and system for passive detection of electromagnetic events associated with destructive devices

• US 5,086,300 A
• Filed: 05/29/1990
• Issued: 02/04/1992
• Est. Priority Date: 05/29/1990
• Status: Expired due to Fees

• Current Assignee: George A. Ashmore
• Original Assignee: George A. Ashmore
• Inventors: Ashmore, George A.
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US07/529,422
• Time in Patent Office: 616 Days
• Field of Search: 342/175, 342/61, 342/20, 342/351, 455/227, 455/1, 455/229
• US Class Current: 342/20
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

The apparatus of the invention detects, characterizes and evaluates electromagnetic radiation, primarily in the radio frequency range, which is emitted by the fusing portion of the explosive train found in certain destructive devices. The apparatus includes a chamber for containing items to be tested, such as airline luggage, in a sealed or confined environment shielded from outside radiation and subjecting any fusing devices, which may be located in such items, to the condition or conditions under which such devices are activated. The invention further includes equipment for receiving, detecting, and evaluating any electrical signals emitted by such fusing devices. The invention is primarily for use in determining the presence of hazards in aircraft cargo but can easily be adapted for other uses.

Claims

1. A passive detector system for detecting low intensity radio frequency emissions from an apparatus that may include a fusing portion of an explosive train, comprising:

antenna means positioned to receive low intensity radio frequency energy originating from the apparatus in a sepcified area, wherein the specified area includes an automatic material handling means for transferring materials into the specific area for evaluation;

receiver means connected to said antenna means for selecting predetermined frequency ranges for reception and amplifying any low intensity radio frequency energy received in said ranges;

detector means connected to said receiver means for quantifying the received low intensity radio frequency energy; and

computer means connected to said detector means for evaluating and characterizing the detected radio frequency energy.

2. A detector system as claimed in claim 1 wherein the specified area is shielded from outside radio frequency emission.

3. A detector system as claimed in claim 1 wherein the receiver means and detector means are operated under the control of the computer means.

4. A detector system as claimed in claim 1 wherein the antenna means is a multi-element device incorporating a switch means so that specific areas within the specified area can be sensed for radio frequency energy.

5. A detector system as claimed in claim 1 wherein the antenna means is movable so that the specific locations of the radio frequency energy within the specified area can be determined.

6. A detector system as claimed in claim 1 wherein the computer means for evaluating and characterizing any detected radio frequency energy is connected to a human interface means for the display of information on said detected radio frequency energy developed by said computer means.

7. A detector system as claimed in claim 1 wherein the computer means for evaluating and characterizing any detected radio frequency energy is connected to a modem for the transfer of data on detected radio frequency energy developed by said computer means to a remote site.

8. A detector system for detecting low intensity radio frequency emissions comprising:

a. antenna means positioned to receive radio frequency energy from a specified area, said specified area being a vacuum chamber which can be evacuated to a partial pressure;

b. receiver means connected to said antenna means for selecting predetermined frequency ranges for reception and amplifying any radio frequency energy received in said ranges;

c. detector means connected to said receiver means for quantifying any received radio frequency energy; and

d. computer means connected to said detector means for evaluating and characterizing any detected radio frequency energy.

9. A detector system as a detector system as claimed in claim 8 wherein the vacuum chamber is evacuated under the control of the computer means.

10. A detector system as claimed in claim 8 wherein the vacuum chamber is a sealed chamber with a sealable opening.

11. A detector system as claimed in claim 8 wherein the vacuum chamber is a partially confined space connected to the ambient environment by baffling means.

12. A detector system as claimed in claim 8 wherein the vacuum chamber is connected to the ambient environment by at least one vent means closed by a frangible member to provide pressure relief for explosive overpressure from materials under evaluation in said chamber.

13. A detector system for detecting low intensity radio frequency emissions comprising:

a. antenna means positioned to receive radio frequency energy from a specified area, said specified area being a pressure chamber which can be controlled to a partial pressure;

b. receiver means connected to said antenna means for selecting predetermined frequency ranges for reception and amplifying any radio frequency energy received in said ranges;

c. detector means connected to said receiver means for quantifying any received radio frequency energy; and

d. computer means connected to said detector means for evaluating and characterizing any detected radio frequency energy.

14. A method for preventing explosive devices from being introduced into public conveyances or other areas of security concern, comprising the steps of:

locating a suspect item in a containment vessel shielded from electromagnetic energy; and

passively detecting in the containment vessel electromagnetic events associated with active or passive electrical fusing used to initiate or detonate any explosive device.

15. The method as described in claim 14 further including the step of:

evaluating and characterizing the electromagnetic events to determine the type of electrical fusing.

16. The method as described in claim 14 further including the step of:

detonating the explosive device in the containment vessel.

17. A method for preventing explosive devices from being introduced into public conveyances, comprising the steps of:

locating a suspect item in a containment vessel shielded from electromagnetic energy;

modifying the pressure in the containment vessel to simulate a predetermined operating condition associated with the public conveyance; and

passively detecting in the containment vessel electromagnetic events associated with active or passive electrical fusing used to initiate or detonate an explosive device.