Passive Microwave Fire and Intrusion Detection System Including Black Body and Spectral Emission at the Hydrogen, Hydroxyl and Hydrogen Chloride Lines

• US 20090252196A1
• Filed: 12/17/2008
• Published: 10/08/2009
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Icove & Associates LLC
• Original Assignee: Icove & Associates LLC
• Inventors: Lyster, Carl T., Icove, David J.
• Granted Patent: US 8,049,620 B2
• Time in Patent Office: Days
• US Class Current: 374/122
• CPC Class Codes: G01K 11/006 using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object G01K17/003, G01J5/00 take precedence; measuring the effect of a material on X-, gamma- or particle radiation G01K11/30
• CPC Class Codes: G08B 13/189 using passive radiation detection systems
• CPC Class Codes: G08B 13/2491 Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field
• CPC Class Codes: G08B 17/12 Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions
• CPC Class Codes: G08B 19/005 combined burglary and fire alarm systems
• CPC Class Codes: G08B 29/183 Single detectors using dual technologies G08B13/1672, G08B13/2448, G08B13/2494 take precedence

Abstract

A passive microwave receiver array, operating in the one meter to sub-millimeter wavelengths range and including an internationally protected range of frequencies of varying bandwidth, may be used for fire and intrusion detection. One or more receiver arrays can be used to provide a plurality of frequency ranges that can be detected. In an interior installation, one or more receiver arrays can be placed inside a wall made of non-metallic substance and capable of passively receiving frequencies at less than 3 GHz. In other embodiments, the receiver and array can be in the form of a hand-held or wearable device. This method and apparatus achieves high performance by exploiting conventional low noise amplification block conversion circuits and provides the detection of thermal signals through clear, smoky, misty, or environmentally untenable conditions as well as the detection of fire and intrusion events via black box or spectral line emission at hydrogen, hydroxyl radical or HCl spectral line emission where an HCl spectral line detector may be mounted on a wall or pole and have line-of-sight view of an intruder or fire.

Claims

1. A method for detecting at least one of a fire and an intruder using passive reception of microwave radiation, comprising:

receiving a first microwave radiation signal at a first receiver, said first receiver including a first antenna, a first frequency of said first received microwave radiation signal being indicative of a temperature of a source of said first microwave radiation;

receiving a second microwave radiation signal at a second receiver, said second receiver including a second antenna, a second frequency of said second microwave radiation signal being indicative of a temperature of a source of said second microwave radiation, wherein said first and second frequencies are within a range of frequencies not being used for active transmission in a geographic area encompassing a location of said first and second receivers, a second range of frequencies being between 0.5 and 3 GHz for capturing a hydrogen line and a hydroxyl radical line;

storing a black box radiation frequency characteristic for a human body and for a fire in memory of a central computer for said 0.5 to 3 GHz frequency range; and

comparing said first frequency with said second frequency and with said black box radiation frequency characteristic to determine a presence of at least one of a fire and an intruder at said central computer.

2. The method according to claim 1, further comprising:

transmitting said first and second microwave radiation signals to a signal processor;

said first microwave radiation signal being converted to a first voltage signal;

said second microwave radiation signal being converted to a second voltage signal;

said first voltage signal being subtracted from said second voltage signal to provide a resulting voltage signal; and

said presence of said at least one of said fire and said intruder being determined based on said resulting voltage signal.

3. The method according to claim 2, wherein a presence of a fire can be determined if said resulting voltage signal is positive.

4. The method according to claim 2, wherein a presence of a living being can be determined if the resulting voltage signal is negative.

5. The method according to claim 4, wherein said negative resulting voltage signal distinguishes a fire from a living being.

6. The method according to claim 1, wherein at least one of said first and second receivers is configured to receive frequencies in one of a range between 1.400 to 1.427 GHz and 1.612231 to 1.720530 GHz.

7. The method according to claim 1, wherein at least one of said first and second frequencies is in a range between 300 MHz and 1000 GHz, the method further comprising determining the presence of a spectral line for HCl within the range.

8. The method according to claim 1, said first receiver being self-adjusting to compensate for a change in temperature of said source of said first microwave radiation signal.

9. The method of claim 2, wherein at least one microwave radiation signal characteristic of a field of view of one of said first and second receiver is stored in a memory of said signal processor, said stored microwave radiation signal being subtracted from a received microwave signal to determine one of an intrusion into and a fire within said field of view.

10. The method of claim 2, further comprising transmitting data via a wireless transmitter, the data representing an identity of at least one of said first and second receivers and their location to said signal processor.

11. A system for passive microwave detection of at least one of a fire and an intruder, comprising:

a first receiver configured to detect a first microwave radiation signal from a first source, a first frequency of said first received microwave radiation signal being indicative of a temperature of said first source;

at least one second receiver configured to detect a second microwave radiation signal from a second source, a second frequency of said second microwave radiation signal being indicative of a temperature of a source of said second microwave radiation, said second frequency being indicative of the presence of one of the hydrogen and the hydroxyl radical spectral line wherein said first and second frequencies are within a range of frequencies not being used for active transmission in a geographic area encompassing a location of said first and second receivers;

a signal processor, said signal processor being configured to receive said first and second microwave radiation signals from said first and second receivers and being further configured to convert said first and second microwave radiation signals to first and second voltages, respectively, said signal processor further being configured to subtract said second voltage signal from said first voltage signal to obtain a resulting voltage signal;

wherein a presence of a fire can be determined if said resulting voltage signal is positive; and

wherein a presence of a living being can be determined if said resulting voltage signal is negative.

12. The system according to claim 11, wherein at least one of said first and second receivers comprises one of a point antenna, a flat antenna array, a parabolic antenna array, a horn-type antenna array, and a directional cellular telecommunication pole antenna array.

13. The system according to claim 12, wherein at least one of said first and second receivers comprises a telecommunication pole antenna array used to send and receive cellular telecommunications signals.

14. The system according to claim 11, wherein at least one of said first and second receivers is configured to receive frequencies in one of a range between 1.400 to 1.427 GHz, 1.612231 to 1.720530 GHz, and between 625 and 626 GHz.

15. The system according to claim 11, wherein said first and second receivers are configured to be placed in spaced-apart locations in a wall of an enclosed space made of one of drywall, brick, block, adobe and concrete, at least one of said first and second receivers being directional and providing a main lobe from a wall of said enclosed space to at least a center of said enclosed space.

16. The system according to claim 15, wherein at least one of said first and second receivers are configured to be placed within a wall of said enclosed space and directed toward the center of an opening to said space comprising one of a window, a gate and a door.

17. The system according to claim 11, further comprising a display, said display being configured to show information regarding at least one of said fire or said intruder comprising one of a visual representation of said space at a given microwave frequency and a graph of microwave frequency versus spectral microwave frequency emission across a received microwave band.

18. The system according to claim 11, wherein said signal processor comprises a superheterodyne receiver.

19. The system according to claim 11, wherein said signal processor includes a memory, and further wherein at least one microwave radiation signal characteristic of a field of view for said second receiver is stored in said memory, said stored microwave radiation signal being subtracted from a received microwave signal to identify at least one of a fire and an intrusion into said field of view.

20. The system according to claim 15, further comprising third, fourth, and fifth receivers, wherein each of said second, third, fourth, and fifth receivers is placed in or one a wall of said enclosed space and said first receiver is placed in a location in said enclosed space whereby a reference temperature signal may be received.

21. A method for detecting at least one of a fire and an intruder using passive reception of microwave radiation, comprising:

receiving a microwave radiation signal at a receiver, said receiver including at least one antenna, a frequency of said received microwave radiation signal being indicative of a temperature of a source of said microwave radiation, one frequency comprising the frequency representing the hydrogen chloride spectral line and another frequency being in the frequency range between 0.5 and 2.5 GHz, wherein said one or another frequency is within a range of frequencies not being used for active transmission in a geographic area encompassing a location of said receiver;

wherein said source of said microwave radiation is one of black body emission and spectral line emission from one of a fire and an intruder.

22. The method according to claim 21, further comprising:

transmitting said microwave radiation signal to a signal processor, said microwave radiation signal being converted to a voltage signal and being transmitted with its associated frequency or frequency range;

said presence of said at least one of said fire and said intruder being determined based on said voltage signal and frequency or frequency range.

23. The method according to claim 22, wherein a presence of a fire can be determined if said voltage signal is positive.

24. The method according to claim 22, wherein a presence of a living being can be determined if said voltage signal is negative.

25. The method according to claim 24, wherein said negative voltage signal distinguishes a fire from a living being.

26. The method according to claim 21, wherein said receiver is configured to receive a passive microwave radiation signal representing one of the hydrogen and hydroxyl radical spectral line.

27. The method according to claim 22, wherein data representing at least one microwave radiation signal is stored in a memory of said signal processor, said stored microwave radiation signal being subtracted from said received passive microwave radiation signal to determine a presence of at least one of a fire and an intruder in said field of view.

28. An apparatus for passive microwave detection of at least one of a fire and an intruder, comprising:

a receiver configured to detect a microwave radiation signal from a first source, a frequency of said received microwave radiation signal being indicative of a temperature of said first source, said frequency being within a range of frequencies not being used for active transmission in a geographic area encompassing a location of said receiver including the hydrogen line at 21 cm and the hydroxyl line within a frequency range from 1.612231 to 1.720530 GHz;

an antenna configured to passively detect a microwave radiation signal from a predetermined source, the apparatus being self-adjusting for changes in temperature of the predetermined source; and

a signal processor configured to compare said received microwave signal to said microwave signal from said predetermined source to provide a resulting voltage signal; and

a memory for storing a black body emission characteristic for passive microwave reception across a portion of the microwave spectrum;

wherein a presence of at least one of a fire and an intruder is determinable from said resulting voltage signal via comparison with said black body emission characteristic data.

29. The apparatus of claim 28, wherein said apparatus is configured to be one of a hand-held device, worn by a person or a vehicle.

30. The apparatus of claim 28, wherein said apparatus is configured to be worn by a user and said predetermined source comprises a part of a human body.

31. The apparatus of claim 28, further comprising a transmitter configured to wirelessly transmit information regarding said passively detected microwave signal and its frequency to a remote signal processor for processing.

32. The apparatus of claim 28, wherein said receiver is configured to receive frequencies in a further frequency range including a microwave spectral emission of HCl.