U.S. patent application number 13/436737 was filed with the patent office on 2012-08-09 for detection of distant substances.
Invention is credited to Stephen T. Braunheim, Ron R. Goldie.
Application Number | 20120200415 13/436737 |
Document ID | / |
Family ID | 45877343 |
Filed Date | 2012-08-09 |
United States Patent
Application |
20120200415 |
Kind Code |
A1 |
Braunheim; Stephen T. ; et
al. |
August 9, 2012 |
DETECTION OF DISTANT SUBSTANCES
Abstract
Disclosed are embodiments of methods and apparatus related to
detection of substance(s) at a distance. For example, an apparatus
can have a mount structure and an emitter mounted to the mount
structure and configured to be trained on a target. The emitter can
have a source configured to emit radiation and a mirror configured
to direct the radiation toward the target. The apparatus can also
have a collector mounted to the mount structure and configured to
be trained on the target at the same time the emitter is trained on
the target and concentrate collected radiation on a sensor. The
apparatus can also have a detection system comprising the sensor
and an interferometer configured to produce an interferogram. The
processor can be configured to perform a Fourier transform on the
interferogram to produce a spectrogram and analyze the spectrogram
to determine presence or absence of known substances in or around
the target.
Inventors: |
Braunheim; Stephen T.; (Los
Angeles, CA) ; Goldie; Ron R.; (Los Angeles,
CA) |
Family ID: |
45877343 |
Appl. No.: |
13/436737 |
Filed: |
March 30, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12508511 |
Jul 23, 2009 |
8148689 |
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13436737 |
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61083496 |
Jul 24, 2008 |
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Current U.S.
Class: |
340/600 ;
250/338.1 |
Current CPC
Class: |
G01N 21/3563 20130101;
G01N 21/359 20130101; G01N 2021/3595 20130101; G01N 21/3581
20130101; G01N 2021/1793 20130101 |
Class at
Publication: |
340/600 ;
250/338.1 |
International
Class: |
G08B 17/12 20060101
G08B017/12; G01J 5/10 20060101 G01J005/10 |
Claims
1. A rotating, scanning apparatus for distant detection of
substances in an angular range, the apparatus comprising: a mount
structure; an emitter mounted to the mount structure and configured
to illuminate a target located at an unknown distance from the
emitter; a collector mounted to the mount structure and configured
to collect radiation from the direction of the illuminated target,
the collected radiation comprising radiation emitted from the
target as may be modified by interactions with any vapor on or near
the target; a detection system mounted to the mount structure
comprising a sensor and a processor, the sensor configured to
measure the collected radiation and the processor configured to
detect, at or near real time, the presence or absence of a
substance or plurality of substances in or around the target based,
at least in part, on the collected radiation measured by the
sensor; where the mount structure has a rotating portion configured
to rotate at least the emitter and the collector to sweep through
an angular range such that the processor may, continuously and in
substantially real time, determine the presence or absence of a
substance or plurality of substances in or around a plurality of
targets located at different angles from the apparatus within the
angular range.
2. The apparatus of claim 1, wherein the rotating portion is
configured to rotate at least 360 degrees.
3. The apparatus of claim 1, wherein the processor comprises
multiple computers.
4. The apparatus of claim 1, wherein the emitter and collector are
configured to address targets at least 10 yards away.
5. The apparatus of claim 1, wherein the emitter and collector are
configured to address targets at least 100 yards away.
6. The apparatus of claim 1, wherein the target comprises an
illuminated portion of the angular range, and wherein the collector
and detection system are configured to scan at a rate of at least
10 Hz, where each cycle comprises determining the presence or
absence of a substance or plurality of substances in or around the
target.
7. The apparatus of claim 6, wherein the collector and detection
system are configured to scan at a rate of at least 100 Hz, where
each cycle comprises determining the presence or absence of a
substance or plurality of substances in or around the target.
8. The apparatus of claim 6, wherein the collector and detection
system are configured to scan at a rate of at least 1,000 Hz, where
each cycle comprises determining the presence or absence of a
substance or plurality of substances in or around the target.
9. The apparatus of claim 6, wherein the collector and detection
system are configured to scan at a rate of at least 10,000 Hz,
where each cycle comprises determining the presence or absence of a
substance or plurality of substances in or around the target.
10. The apparatus of claim 1, wherein the processor is configured
to determine the presence or absence of a substance or plurality of
substances in substantially real time by conveying to a user
presence or absence of a substance or plurality of substances
within 10 seconds or less of collecting radiation from the
direction of the illuminated target.
11. The apparatus of claim 1, wherein the processor is configured
to determine the presence or absence of a substance or plurality of
substances in substantially real time by conveying to a user
presence or absence of a substance or plurality of substances
within 1 second or less of collecting radiation from the direction
of the illuminated target.
12. The apparatus of claim 1, wherein the processor is configured
to determine the presence or absence of a substance or plurality of
substances in substantially real time by conveying to a user
presence or absence of a substance or plurality of substances
within 0.1 seconds or less of collecting radiation from the
direction of the illuminated target.
13. The apparatus of claim 10, wherein the apparatus is further
configured to correlate the angle at which the presence or absence
of a substance or plurality of substances was measured, thereby
enabling a user to determine the angular direction of a potential
threat.
14. The apparatus of claim 13, wherein the apparatus is further
configured to indicate the approximate distance from the apparatus
to the target that resulted in information regarding the presence
or absence of a substance or plurality of substances, thereby
enabling a user to determine the distance to a potential
threat.
15. The apparatus of claim 1, further comprising a user interface
configured to display information about the detected substance.
16. The apparatus of claim 1, wherein the emitter has a power of
more than 100 watts.
17. The apparatus of claim 16, wherein the emitter has a power in
the range of about 100 watts to about 1000 watts.
18. The apparatus of claim 1, wherein the substance or plurality of
substances may include one or more molecules related to
explosives.
19. The apparatus of claim 18, wherein the one or more molecules
related to explosives may include one or more of TNT, RDX, DNT,
HMX, plastic explosives, SEMTEX, nitroglycerine, and TAP.
20. The apparatus of claim 1, wherein the angular range is at least
90 degrees.
21. The apparatus of claim 1, wherein the angular range is at least
180 degrees.
22. The apparatus of claim 1, wherein the angular range is about
360 degrees.
23. The apparatus of claim 1, wherein the emitter illuminated the
target with a collimated pencil-beam of electromagnetic
radiation.
24. The apparatus of claim 23, wherein the collimated pencil-beam
of electromagnetic radiation comprises infrared electromagnetic
radiation.
25. A safety and alert system for detecting one or more distant
volatile substances and informing a user, the system comprising: a
rotating infrared radiator configured to sweep a beam of
directional infrared radiation through a relevant angle to scan the
horizon for targets, the horizon located at a distance of at least
10 yards from the safety and alert system; a rotating radiation
collector configured to also sweep its field of view through the
same relevant angle of the rotating infrared radiator, collecting
radiation from potential targets illuminated thereby; a detector
and processor configured to receive the radiation from the
collector and spectroscopically determine the presence or absence
of one or more volatile substances at or near the target based at
least on comparison of results from the collected radiation with a
library of data from known volatile substances; and a warning
interface configured to receive information from the processor and
alert the user to the presence of one or more volatile
substances.
26. The system of claim 25, wherein the warning interface is
further configured to indicate the approximate location of the one
or more volatile substances.
27. The system of claim 25, wherein the processor is configured to
spectroscopically determine the presence or absence of one or more
volatile substances using a Fourier transform of a spectral
signature.
28. The system of claim 27, wherein the library of data includes
information from Fourier transforms of spectral signatures of known
volatile substances.
29. The system of claim 25, wherein the library of data from known
volatile substances includes results from one or more explosive
accelerants.
30. The system of claim 25, wherein the processor comprises a
Fourier transform infrared spectrometer.
31. The system of claim 25, wherein the rotating radiation
collector comprises a parabolic mirror configured to focus
collected radiation on the sensor.
32. The system of claim 25, wherein the infrared radiator is a
substantially collimated infrared searchlight with an output power
of at least 100 watts.
33. A method of detecting distant volatile substances within an
angular range, the method comprising: rotating an infrared
illuminator to sweep a beam of directional infrared radiation
through an angular range to scan the horizon for targets, the
horizon located at a distance of at least 10 yards from the
infrared illuminator; rotating a radiation collector capable of
collecting radiation from an illuminated target within the angular
range; synchronizing the rotations of the infrared illuminator and
the radiation collector such that the radiation collector will
sweep its field of view through the same angular range as the
infrared illuminator, and will collect radiation emitted from the
illuminated target as may be modified by interactions with any
vapor on or near the target; sensing the collected radiation from
the radiation collector; analyzing, in substantially real time, the
collected radiation from the radiation collector to
spectroscopically determine the presence or absence of one or more
volatile substances at or near the target based at least on
comparison of results from the collected radiation with a library
of data from known volatile substances; and alerting a user of the
presence of one or more volatile substances at or near the target.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/508,511, filed Jul. 23, 2009, titled
"DETECTION OF DISTANT SUBSTANCES," which claims the benefit under
35 U.S.C. .sctn.119(e) of U.S. Provisional Patent Application No.
61/083,496, filed Jul. 24, 2008, titled "DETECTION OF DISTANT
SUBSTANCES," the entirety of which is hereby expressly incorporated
herein for all that it contains.
BACKGROUND
[0002] 1. Field
[0003] Subject matter disclosed herein relates generally to
detection and/or identification of substances. For example,
spectroscopic analysis may be performed at a distance using a beam
of radiation that passes through and/or reflects off a substance to
be measured. Spectroscopic devices are discussed.
[0004] 2. Description of Related Art
[0005] Materials, such as explosives and drugs, can emit substances
that are detectable. For example, such substances can include
volatile organic compounds that are detectable by their odor.
Detection of such substances (e.g., by a canine trained to alert to
a particular odor) can be used to determine the presence of the
material that emits the substance. Trained canines generally must
be relatively close to the material in order to detect the
substance (e.g., by sniffing a target suspected of carrying the
material).
SUMMARY
[0006] Disclosed system embodiments are capable of detecting and/or
identifying substances that are located at a distance from the
system. Certain such embodiments propagate a beam of radiation
(e.g., infrared radiation) toward a distant target that may be
carrying material or contraband that emits the substance (e.g., a
suspect carrying concealed drugs or explosives). The beam of
radiation interacts with the substance and at least a portion of
the beam of radiation returns to a sensor (e.g., by reflection from
the target or a vapor halo adjacent the target). The sensed
radiation is analyzed for the presence of one or more substances.
In some embodiments, the sensed radiation is spectroscopically
analyzed for a spectral signature of the one or more substances. In
some such embodiments, a Fourier Transform Infrared (FTIR)
spectrometer is used to perform the spectroscopic analysis. In some
embodiments, a neural network is used to identify the spectral
signature of the one or more substances. In some embodiments, a
processor comprising a plurality of processing channels is used to
perform the spectroscopic analysis, with each processing channel
configured to detect a particular substance. In some embodiments, a
suitable signal (e.g., an alert) is provided by the system if at
least one substance of interest is detected.
[0007] In some embodiments, an apparatus for detecting substances
at a distance is disclosed. The apparatus can have: a mount
structure; an emitter mounted to the mount structure and configured
to be trained on a target, the emitter comprising a source
configured to emit radiation and a mirror configured to direct the
radiation toward the target; a collector mounted to the mount
structure and configured to be trained on the target at the same
time the emitter is trained on the target, the collector configured
to collect radiation from the direction of the target and
concentrate the collected radiation on a sensor; and a detection
system comprising the sensor and a Michelson interferometer
configured to produce an interferogram based at least in part on a
signal from the sensor in response to the collected radiation, the
detection system further configured to perform a Fourier transform
on the interferogram to produce a spectrogram and analyze the
spectrogram to determine presence or absence of a substance in or
around the target.
[0008] In some embodiments, a method for detecting substances is
disclosed. The method can include the following steps: emitting
infrared radiation from a source of infrared radiation; reflecting
the infrared radiation from a mirror to provide collimated
radiation; propagating the collimated radiation through a vapor
halo adjacent a target; illuminating a portion of the target with
the collimated radiation; collecting radiation from the illuminated
target; focusing the collected radiation on an infrared sensor to
generate a signal; processing the signal using an to generate an
interferogram; mathematically transforming the interferogram to
generate a spectrogram; automatically analyzing the spectrogram,
via execution of instructions by a computing device, to indicate
presence or absence in the vapor halo adjacent the target of a
substance with known spectroscopic properties; and storing results
of the analysis in a memory.
[0009] In some embodiments, an apparatus for detecting substances
at a distance is disclosed. The apparatus can comprising the
following: a mount configured to be rotatable in at least one
plane; an emitter attached to the mount, the emitter configured to
propagate a collimated beam of emitted radiation toward a target; a
collector attached to the mount, the collector configured to
receive radiation that propagates from the target, at least some of
the received radiation comprising radiation that has interacted
with the target or a vapor halo adjacent the target in response to
the collimated, emitted beam; a Fourier Transform spectrometer
operatively associated with the collector, the Fourier Transform
spectrometer configured to generate a spectrum based at least in
part on the received radiation; and a processor configured to
analyze the spectrum to detect a presence of at least one substance
near the target.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following drawings and the associated descriptions are
provided to illustrate embodiments of the present disclosure and do
not limit the scope of the claims.
[0011] FIG. 1 shows an embodiment of an apparatus for detection of
distant substances.
[0012] FIG. 2 shows an embodiment of an apparatus for detection and
thermal observation of distant substances.
[0013] FIG. 3 illustrates steps of an example method for detecting
a substance.
[0014] These and other features will now be described with
reference to the drawings summarized above. The drawings and the
associated descriptions are provided to illustrate embodiments and
not to limit the scope of any claim. Throughout the drawings,
reference numbers may be reused to indicate correspondence between
referenced elements.
DETAILED DESCRIPTION
[0015] Although certain preferred embodiments and examples are
disclosed below, inventive subject matter extends beyond the
specifically disclosed embodiments to other alternative embodiments
and/or uses and to modifications and equivalents thereof. Thus, the
scope of the claims appended hereto is not limited by any of the
particular embodiments described below. For example, in any method
or process disclosed herein, the acts or operations of the method
or process may be performed in any suitable sequence and are not
necessarily limited to any particular disclosed sequence. Various
operations may be described as multiple discrete operations in
turn, in a manner that may be helpful in understanding certain
embodiments; however, the order of description should not be
construed to imply that these operations are order dependent.
Additionally, the structures, systems, and/or devices described
herein may be embodied as integrated components or as separate
components. For purposes of comparing various embodiments, certain
aspects and advantages of these embodiments are described. Not
necessarily all such aspects or advantages are achieved by any
particular embodiment. Thus, for example, various embodiments may
be carried out in a manner that achieves or optimizes one advantage
or group of advantages as taught herein without necessarily
achieving other aspects or advantages as may also be taught or
suggested herein. Further, no single feature described herein is
required or indispensable for each particular embodiment.
[0016] FIG. 1 illustrates an embodiment of a system 110 for
detecting substances. The system 110 can comprise a mount structure
112, to which is mounted an emitter 120 and a collector 140. The
emitter 120 can comprise a source 122 that radiates emitted
radiation 126 that is reflected off a surface of a mirror 124 and
directed toward a target 134. The emitter can emit infrared
radiation for example. The emitter 120 can have a radiation
processor 130 that is mounted thereon as shown or otherwise
associated therewith. The mirror 124 can be a parabolic mirror, or
can be otherwise shaped in order to cause the emitted radiation 126
to be collimated or conditioned appropriate to the circumstance.
The mount structure 112 can be configured to rotate and scan in an
angular range (e.g., in a horizontal plane) for example, and can
also be configured to rotate in the vertical plane if desired. In
some embodiments, the angular range is 360 degrees. In other
embodiments, the angular range is 10 degrees, 30 degrees, 45
degrees, 90 degrees, 180 degrees, or some other angular range. The
mount structure 112 can have a controller 114 that can be
configured to control the physical movement of the mount structure
112 and can also be configured to control a user interface, for
example, not shown.
[0017] The emitted radiation 126 is directed toward a target 134
that can have a vapor halo 135 surrounding it. The target 134 can
be fixed or moving and may be a person, animal, object, building,
structure, geological formation or feature, etc. The vapor halo 135
may include one or more substances that are to be detected and/or
identified by the system 110. For example, the vapor halo 135 may
include substances emitted by explosives, contraband, drugs (e.g.,
cocaine, cannabis, methamphetamines, etc.), hazardous materials,
and so forth that may be carried by, stored in, or otherwise
associated with the target 134. The emitted radiation 126 can
interact with the target 134 or the general vicinity of the target
134 (e.g., the vapor halo 135). For example, the emitted radiation
can be reflected by the target 134 and/or absorbed by the target
134. The emitted radiation 126 can also be reflected, scattered,
absorbed, and/or re-radiated (e.g., by fluorescence) by the vapor
halo 135.
[0018] In some embodiments, the emitted radiation 126 encounters a
portion of the vapor halo 135, which causes a diffuse reflection
(e.g., backscatter) of the emitted radiation 126, and some of the
reflected radiation 136 is directed toward the collector 140. Some
of the emitted radiation may pass through the vapor halo 135,
reflect off the target 134, and pass a second time through the
vapor halo 135 before returning to the collector 140. However, if
the emitted radiation 126 is radiation of a particular wavelength
that is at least partially absorbed (and/or scattered) by a
substance within the vapor halo 135, the reflected radiation 136
may include less energy, intensity, flux, and/or other suitable
radiation property than the emitted radiation 126 at the absorbed
wave length. The reduced amount of radiation at the absorbed
wavelength can be observed by the collector 140, e.g., as a
spectral absorption feature. In some cases, the emitted radiation
126 is absorbed and re-radiated by substances in the vapor halo
135. The re-radiated radiation can be observed by the collector
140, e.g., as a spectral emission feature. The properties of the
reflected radiation 136 (or re-radiated emission from the vapor
halo), as gathered by the collector 140, can be determined by a
detection system 150, for example.
[0019] In certain embodiments, the controller 114 is configured to
control the physical movement of the mount structure 112 so that
the emitter 120 tracks or follows a moving target. In some such
embodiments, the controller 114 may be configured with tracking
algorithms that automatically track a moving target. In some
embodiments, the system 110 may be configured with tracking optics
(e.g., a tracking scope) such that an operator can manually move
the mount structure 112 to track a moving target. In some
embodiments, a combination of operator-controlled and automated
techniques can be used. Such embodiments of the system 110 can be
used to train the emitted radiation 126 on the moving target and to
allow the collector 140 to collect the reflected radiation 136 as
the target moves relative to the system 110. Certain such
embodiments may provide possible advantages. For example, the
target 134 may initially be at too great a distance for particular
substances to be reliably detected. By tracking the moving target,
the system 110 will be able to detect and/or identify the
particular substances when the target moves within a suitable
range. Also, in some cases, portions of the vapor halo 135 that
contain particular substances may be blocked from receiving the
emitted radiation 126 (e.g., blocked by the target or a structure
behind which the target is hiding). By tracking the target as it
moves, the system 110 can detect and/or identify the particular
substances when these portions of the vapor halo come into view of
the system 110 (e.g., are able to receive the emitted radiation
126).
[0020] In one example of a system 110 for detecting substances, the
power of the source 122 is about 100 watts, and in some embodiments
the power of the source 122 is in the range of about 100 watts to
about 1000 watts. For example, 500 watts can be used. Other source
powers can be used. In some embodiments, multiple sources 122 can
be included. For example, a single lamp may not be able to produce
an emitted radiation 126 beam with a temperature much larger than
1300 Kelvin. Thus, an array or set of multiple radiation lamps can
be used as the source 122. In some embodiments, a source 122 that
is fed with a power of 100 watts can radiate at approximately 1000
Kelvin. A 140 watt lamp can advantageously be used, and, in some
embodiments, such a lamp may not radiate in the visible range of
wavelengths. A lamp that does not radiate in the visible range has
the benefit of being harder to see for humans who may be attempting
to see a beam of emitted radiation 126 while a device such as the
system 110 is in operation. Thus, a system that is stealthy and/or
difficult to detect visually, can have many advantages. In some
embodiments, radiation from the source 122 may pass through one or
more filters to provide a desired wavelength range for the emitted
radiation 126. In some embodiments, various optical elements may be
used to process, modify, or redirect the radiation from the source
122 such as, e.g., lenses, mirrors, gratings, dispersive or
diffractive elements, modulators, stops, and so forth.
[0021] In some embodiments, the mirror 124 can be positioned such
that the source 122 is at the focal point of the mirror 124. For
example, the optics of the system 110 can be designed such that the
source produces emitted radiation 126 that reflects off the mirror
124 into a collimated beam, much like a search light. In some
embodiments, the diameter of the parabolic mirror is 10 inches. In
some embodiments, the diameter of the parabolic mirror is 20
inches. The mirror 124 can be gold-plated or coated with a material
that is highly reflective to radiation in a wavelength range (e.g.,
the wavelength range of the emitted radiation 126). In some
embodiments, the mirror 124 causes radiation from the source 122 to
create an emitted radiation beam 126 that is narrow, collimated,
and approximately the size of a pencil. In some embodiments, the
narrow, collimated beam has a size that is smaller than the target
and/or the vapor halo, about the same size as the target and/or the
vapor halo, or larger than the target and/or the vapor halo.
[0022] In some embodiments, the mirror 124 (and/or other optical
elements) can be configured so that the emitted radiation 126
converges or is focused. For example, in some embodiments, the
mirror 124 has a shape that is substantially an ellipse, the source
122 is positioned at a first focus of the ellipse, and the emitted
radiation 126 converges at the second focus of the ellipse. Such
embodiments advantageously may be used to deliver radiation to a
focal point or focal region that may be smaller than the target 134
or the vapor halo 135. Such embodiments may also concentrate the
emitted radiation 126 in the focal region, which may, in some
cases, cause greater interaction with the substances to be
detected, and a larger amount of reflected radiation 136 is
returned to the system 110 for analysis.
[0023] The radiation processor 130 can be configured to control the
intensity, power, wavelength, signal pattern, frequency or
wavelength distribution, and/or other parameters of the source 122.
The radiation processor 130 can also be configured to control the
relative position of the source 122 and the mirror 124, which can
be fixed and/or movable, for example. The radiation processor can
be configured to detect radiation emitted directly from the source
122 to determine if the source 122 is working properly, for
example. The radiation processor 130 can provide input to the
controller 114, which can be used to determine the reliability
and/or parameters of the emitted radiation 126. The radiation
processor 130 can be used to change the emitted radiation 126 by
controlling and/or changing a radiation parameter. The radiation
parameter can be chosen by a user and a radiation parameter may
correspond to a substance (e.g., a chemical in vapor phase) to be
detected. In some embodiments, the radiation processor determines
the rate at which emitted radiation 126 is periodically (or
non-periodically) emitted. For example, the emitted radiation 126
may be pulsed. In some embodiments, the radiation emitted by the
emitter 120 is within the infrared portion of the electromagnetic
spectrum. For example, the emitter 120 can emit radiation in the
approximate range of 8 to 14 micrometers. In some embodiments, the
radiation emitted by the emitter 120 corresponds to a temperature
that is approximately room temperature (300 Kelvin). In some
embodiments, the radiation emitted by the emitter 120 is in the
range of 8 to 9 micrometers. In some embodiments, the radiation
emitted by the emitter 120 is in the mid-infrared range. In some
implementations, the source 122 may emit thermal radiation (e.g.,
at a temperature in a range from about 300 Kelvin to about 1500
Kelvin). The thermal radiation may be filtered to provide a
suitable wavelength range (e.g., about 8 to 14 micrometers) for the
emitted radiation 126. Other wavelength ranges can be used
including, for example, visible, near-infrared, and/or far-infrared
wavelengths. For example, in various embodiments the wavelength
range may comprise infrared wavelengths in a range from about 0.8
to 2 micrometers, from about 2 to 14 micrometers, and/or from about
5 to 8 micrometers. In some embodiments, the wavelength range may
be selected to include one or more spectral features of interest in
the spectrum of a substance. For example, TNT
(2,4,6-trinitrotoluene) has strong infrared spectral features at
about 6.4 and 7.3 micrometers. The spectral features may include
molecular vibrational spectral features of substances of interest
(e.g., TNT). In some embodiments, the wavelength range comprises a
narrow-band substantially centered around the spectral features
(e.g., a band of a few micrometers around one or both of the TNT
spectral features).
[0024] The collector 140 can be a telescope that is aligned to
collect a portion of the emitted radiation 126 that is reflected
(and/or scattered) off of the target 134 after having passed
through at least a portion of the vapor halo 135. Thus, in some
embodiments, the collector 140 and the emitter 120 can be aligned
toward the same portion of the target 134 (which can be, for
example, approximately the same radius as a common pencil). The
collector 140 can comprise a mirror (not shown) that, in some
embodiments, can be similar to the mirror 124. For example, a
mirror in the collector 140 can be a highly reflective gold-plated
mirror. In some embodiments, the diameter of a mirror within the
collector 140 can correspond to a diameter of the mirror 124 in the
emitter 120. In some embodiments, the collector 140 can comprise a
10 inch F/3 parabolic mirror.
[0025] The collector 144 can have a detector (not shown) that can
be located at the focal point of a parabolic mirror, in a similar
fashion to that illustrated with respect to the source 122 and the
mirror 124 in the emitter 120. In some cases, a secondary mirror
(not shown) may be used to direct the radiation to a different
focal configuration such as, e.g., a Newtonian or Cassegrain focus.
The detector (not shown) can be located within the collector 140
(or at an alternative focal configuration). In some embodiments,
the detector comprises an infrared detector such as, e.g., a
Mercury Cadmium Telluride (MCT) detector. Other detectors can be
used such as, e.g., Indium Antimonide detectors, quantum well
infrared photodetectors (QWIP), etc. In some embodiments, a
multi-element detector array is used. In some embodiments, such a
detector can be kept at a low temperature to improve sensitivity.
For example, in some embodiments, an MCT detector can be kept at
approximately 77 Kelvin (e.g., by cooling with liquid nitrogen). In
some embodiments, a Sterling cycle cooler can be used to keep a
detector at a low temperature. Other coolers may be used such as,
e.g., thermoelectric coolers.
[0026] In some embodiments, a detector can be designed to detect
multiple wavelengths of radiation. For example, the detector can
target a range of electromagnetic radiation that is within a
window, to avoid interference from other absorbing molecules that
may be in the atmosphere between the system 110 and the target 134.
For example, the emitted radiation 126 may pass through water vapor
or other substances in the air before the emitted radiation 126
reaches the vapor halo 135 of the target 134. The reflected
radiation 136 may also pass through water vapor or other substances
on the return path to the collector 140. The detector, by being
tuned to a particular range of wavelengths within a window that is
not affected by water vapor absorbents (and/or other spectral
interferents), can be more highly sensitive to the particular
substances within the vapor halo 135, and capable of detecting them
without interference. In some embodiments, a detector within the
collector 140 can comprise an interferometer that is located at the
focal point of a mirror. In some embodiments, the detector is a
portion of an interferometer, which can be designed as a Michelson
interferometer, a Twyman-Green interferometer, a Fabry-Perot
interferometer, or other suitable interferometer, for example. The
detector can comprise a Fourier Transform Infrared (FTIR)
spectrometer in some embodiments. In some embodiments, the
interferometer is operatively associated with the collector 140 and
generates a spectrogram of the radiation collected by the collector
140. In some implementations, the interferometer is placed on the
ground or a platform (e.g., a table) near the system 110 rather
than being attached or mounted to the mount structure 112. Such
embodiments may allow the interferometer to operate in a stable,
vibration-free environment.
[0027] In some embodiments, the detection system 150 can comprise
an interferometer, that is operatively associated with the
collector 140. In some embodiments, the interferometer can produce
an interferogram. In some embodiments, the data produced by the
interferometer, and/or detection system 150, can be further
processed to produce a spectrogram. For example, the Fourier
transform of an interferogram can produce a spectrogram. The
processing of an interferogram can be achieved very quickly by
taking a Fourier transform, or, a fast Fourier transform, for
example. A helium laser can be used to keep the interferometer
functioning at a constant rate. For example, the phase of the
interferometer is advantageously very regular and precise, and the
helium laser advantageously can be used to synchronize the phase of
the interferometer. The detection system 150 can comprise a
computer processor that performs a Fourier transform and processes
the signal from the collector 140 in other ways, such as through
noise processing, electrical filtering, band-pass filtering, etc.
The computer processor may comprise one or more general or special
purpose computers, application specific integrate circuits, field
programmable gate arrays, programmable logic devices, etc. In some
embodiments, the signal is communicated to a physically remote
computer processor for processing.
[0028] A spectrometer can be used in place of the interferometer,
however, the interferometer can often achieve a result much faster
than a spectrometer. However, a spectrometer can be used to achieve
a more accurate result in some implementations. For example, the
collector 140 and/or detection system 150 can scan at approximately
10,000 cycles per second (Hz). The detection system can scan at
other rates such as 10 Hz, 100 Hz, 1000 Hz, etc. The detection
system 150, which can comprise a Michelson interferometer, can
comprise a spinning mirror that can be used to split the beam of
incoming radiation. The helium laser can be used to control and/or
improve the timing of the spinning mirror. In some embodiments, use
of an interferometer and a processor that takes the Fourier
transform of an interferogram, can achieve a useful output at a
rate that is 50 times faster than a spectrometer. In some
embodiments, the processing of the incoming reflected radiation 136
can be the slowest portion of the process of detecting a substance
by the system 110. In some embodiments, the detection system can
search a library of data to determine the nature of the substances
that are within the vapor halo 135 and/or on the target 134. The
detection system 150 can have access to a computer memory that
stores data relating to known substances. The data can comprise
spectral data relating to the behavior of molecules when those
molecules are exposed to radiation within the range of the emitted
radiation 126. The data can be obtained from academic chemical
studies, and/or from prior use of the system 110 to calibrate with
known substances.
[0029] In some embodiments, the detection system 150 can comprise a
Fourier transform signal that is transmitted to a processor
comprising a bus. The bus can communicate with multiple channels,
each channel comprising at least one processor. In some
embodiments, a channel can be dedicated to the detection of a
particular substance and store data relating to that substance and
an algorithm for determining whether that substance is present.
Thus, a Fourier transform signal can be conveyed to the bus, which
in turn conveys the same Fourier transform signal to each of
multiple channels, each of which returns a signal to the detection
system 150 and/or a user interface (not shown) that indicates an
answer pertaining to the presence or absence of particular
substances. For example, the answer may be a "yes or no" answer, a
likelihood of positive detection, or some other suitable metric
that indicates the presence of the substance. In some embodiments,
the bus can have a plurality of channels. For example, in some
embodiments, 12 channels are implemented, and each of the 12
channels can (but need not) be dedicated to a particular substance.
A different number of channels can be used in other embodiments
such as, e.g., 1, 2, 3, 4, 5, 8, 10, 20, 30, or more channels. In
some embodiments, two or more of the channels may be dedicated to
the same substance, which advantageously may improve reliability,
accuracy, and/or precision of the detection/identification of the
substance. In some implementations, each channel can comprise a
portion of a server blade.
[0030] The processing algorithms contained within any particular
channel (or more than one channel) can comprise a neural network
(e.g., a trained neural network, a double neural network, etc.).
For example, a double neural network can comport with the
principles taught in the Ph.D. thesis of Dr. Benjamin Braunheim.
See also, for example, U.S. Pat. No. 6,587,845, entitled "Method
And Apparatus For Identification And Optimization Of Bioactive
Compounds Using A Neural Network," inventor Benjamin B. Braunheim,
issued Jul. 1, 2003, which is hereby incorporated by reference
herein in its entirety. A neural network algorithm can provide a
fast and accurate result, without requiring a specifically coded
algorithm. Thus, in some embodiments, neural network processing
algorithms can achieve high speed if the parameters are set to run
in a loose enough fashion.
[0031] The result from the detection system 150 can be correlated
with a result from another detector that may be a part of the
system 110. Although not shown, such a separate detector can
comprise a thermal imaging system such as, e.g., a forward looking
infrared (FLIR) system. The result from the detection system 150
can be compared with a result from a FLIR system, and the two
results can be communicated to a user by means of a controller 114
and/or a user interface (not shown) that can be located on the
mount structure 112, for example. If the detection system 150
signals a positive result for a particular substance, and that
signal coincides with a positive result from an FLIR system, a
warning or alarm can be triggered alerting a user to the presence
of that substance.
[0032] Embodiments of the system 110 can be designed to detect
molecules that are related to explosives. Although many molecules
can be used to create explosions, many explosive devices include at
least one molecule from a group of accelerants. For example, many
explosives include the molecule TNT. Many explosives include the
molecule RDX. The molecules DNT (related to TNT) and HMX (related
to RDX) can also be included in explosives. Many molecules such as
TNT and RDX have a very high vapor pressure, and are thus likely to
become vapor and be emitted to form a portion of the vapor halo
135, if a target 134 is carrying, wearing, or has recently
interacted with an explosive substance. Explosives generally have
some degree of out-gassing. Explosive molecules generally do not
emit radiation without being excited, and such molecules can be
excited with a laser beam, for example, but laser beams are
generally too small to be used for scanning an area to detect
suicide bombers that may be approaching from 100 yards away, for
example. Thus, it can be advantageous to emit a pencil-sized beam
of infrared radiation (e.g., using an embodiment of the system
110), which can be invisible to the naked eye, that can be scanned
in a sweeping motion around an army check point, for example.
[0033] The beam of infrared radiation can be directed to people
that may be in a crowd standing off a certain distance from the
detection system 110. The beam of emitted radiation 126 can be
emitted across the distance of approximately 100 yards (for
example), to illuminate people who may be suspected of being
carrying explosives (e.g., suicide bombers). If an explosive
molecule from the small group of accelerants is present in a vapor
halo 135 around a person, the detection system 110 can alert a user
to that fact. Various substances can be programmed into a system
for detection in this manner. The substances that dogs can be
trained to detect can be the substances programmed into the system
110, and in particular programmed into the detection system 150.
The explosive materials can be referred to as accelerants and/or
oxidants and can include, in addition to TNT or DNT and RDX or HMX,
plastic explosives, SEMTEX, nitroglycerine, TAP, etc. Other
substances that are candidates for detection can be found in, for
example, R. J. Harper and K. G. Furton, "Biological Detection of
Explosives" in "Counterterrorist Detection Techniques of
Explosives," Jehuda Yinon, editor, Elsevier (Amsterdam) 2007, pp.
395-432, which is hereby incorporated by reference herein in its
entirety.
[0034] In various implementations, embodiments of the system 110
can be configured to detect and/or identify organic explosives from
one or more explosive classes including nitroaliphatics,
nitroaromatics, nitrate esters, nitramines, and peroxides. For
example, substances that can be detected by embodiments of the
system 110 include, but are not limited to: 2,4-dinitrotolune
(DNT), 2,4,6-trinitrotolunet (TNT), nitroglycerine (NG),
nitrocellulose (NC), pentaerythritol tetranitrate (PETN),
trinitro-triazacyclohexane (RDX), tetranitro-tetracyclooctane
(HMX), hexanitro-hexaazaisowurzitane (CL20), and triacetone
triperoxide (TATP). Diphenylamine, which is commonly present in
smokeless powder explosives, can be included. Other substances that
can be detected and/or identified include byproducts of the
decomposition of explosives (or additives such as plasticizers,
stabilizers, and deterrents). Such byproducts can include acetone,
hydrogen peroxide, and 2-ethyl-1-hexanol, for example.
[0035] Some explosives have relatively low vapor pressure and may
not be present in high concentrations in the vapor halo adjacent
the target. For such explosives, the system advantageously may be
configured to detect and/or identify one or more marker chemicals
with much higher vapor pressures that are commonly added to such
explosives. Marker chemicals include 2,3-dimethyl-2,3-dinitrobutane
(DMNB), 2-nitrotoluene (2-MNT), 4-nitrotoluene (4-MNT), and
ethylene glycol dinitrate (EGDN), for example.
[0036] In some embodiments, the system 110 is configured to detect
and/or identify a set of substances that is representative of a
wide range of explosives (or their decomposition byproducts or
additives such as, e.g., plasticizers). Although the set of
substances may not provide for detection of every possible
explosive, the set of substances can be used to detect and/or
identify most of the commonly available explosives. For example, in
some embodiments, the set of substances can include TNT, DNT, RDX,
EGDN, and DMNB.
[0037] The system 110 can comprise, and/or be used in conjunction
with, a thermal imager. For example, an FLIR thermal imaging system
and/or a night vision system can create thermal images of a
suspect. The result of thermal imaging can be combined with the
result from the system for specific substance detection to create a
combined suspect profile. In some embodiments, the combined suspect
profile is produced by a single system 110 that may include a
thermal imaging capability.
[0038] In some applications for an embodiment of the system 110, a
terrorist transporting explosives (e.g., a suicide bomber), for
example, has not only a chemical signature that indicates the
presence of explosive molecules, but the terrorist also has a
thermal signature that makes the terrorist a different temperature
from the people that surround him or her, or the other background
thermal landscape. For example, an explosive belt can cause the
terrorist (e.g., a would-be suicide bomber) to appear hotter, or
colder, than the surrounding people or objects. Thus, the system
110 can be used to detect and/or verify a suspect of being a
potential threat, and the system can achieve such detection across
large stand-off distances. For example, the system 110 can be used
to detect a terrorist at approximately 100 yards away. In some
embodiments, the system 110 can be used to scan a 360.degree.
angular range around a military check point, searching for
suspected terrorists in a crowd of people.
[0039] Embodiments of the system 110 can be used to detect
explosives stored or carried in vehicles (e.g., a truck
transporting an explosive device), in buildings, in the ground, and
so forth. For example, the emitted radiation 126 can be directed
toward the vicinity of a suspect vehicle to detect and/or identify
explosives in a vapor halo near the vehicle. Many applications of
system embodiments are possible.
[0040] Various aspects of the system 110 can improve scanning
speed. In some implementations, the goal of searching for potential
suicide bombers in real time can be achieved using a combination of
these principles. For example, as described above, use of a
pencil-diameter beam of emitted radiation 126 can improve the
system ability to scan a large amount of space and scan more
quickly. Moreover, use of Fourier transform and/or fast Fourier
transform to process incoming reflected radiation 136 using a
detection system 150, can improve speed while maintaining
acceptable accuracy. Use of neural network processing principles
can also allow fast processing of the resulting signal. In some
embodiments, a real-time scan can be achieved if a single pixel is
processed each 100.sup.th of a second. In some embodiments, 16,000
pixels per minute can be processed. In some embodiments, a scan of
360.degree. can be performed in a single minute, allowing a single
system 110 to continuously scan a full circumference around a check
point, for example, within the time it would require for a
potential suicide bomber to run or walk the distance between the
bomber and the check point. Another aspect of the system 110 that
can improve speed is providing separate processor channels within a
detection system 150 for each of a limited number of known
explosive substances. Limitation of the processing within the
detection system to a certain number of known substances can also
improve speed (e.g., a set of substances representative of the
majority of available explosives).
[0041] As illustrated in FIG. 2, in some embodiments, a scanning
head structure 212 can include both an emitter 220 and a collector
240, as well as a FLIR system 260. FIG. 2 provides a schematic view
of the profile of such a combined apparatus, as it may be seen from
the perspective of a suspect upon which the instruments 220, 240,
and 260 are trained. The FLIR system 260 can scan in multiple
spectral regions (e.g., near-infrared, medium-wave infrared, and/or
long-wave infrared). The use of an FLIR system with the emitter 220
and collector 240 (along with other components of the system 110,
for example) can improve safety at a military check point by
providing more information upon which to base defensive and
offensive decisions. For example, if the FLIR system indicates that
a suspect has a starkly different temperature from its surroundings
and the collector 240 and its processor indicate that the presence
of an explosive substance in vapor on or around the suspect, the
suspect can be even more carefully observed and/or
incapacitated.
[0042] In some embodiments, a system for detecting substances can
operate or be operated according to the example method illustrated
in FIG. 3. In some implementations, an embodiment of the system 110
performs an embodiment of the method illustrated in FIG. 3. For
example, radiation (e.g., infrared radiation) can be emitted from a
source (or array of sources), as shown at 312. Radiation can be
reflected from a mirror (e.g., a gold-coated parabolic mirror) and
collimated, as shown at 314. The radiation can be propagated
through a vapor halo (e.g., a vapor halo of vaporized explosive
components) and illuminate a portion of a target, as shown at 316.
Reflected radiation can be collected from the illuminated target or
portion of a target (e.g., with a telescope), as shown at 318.
Collected radiation can be focused (e.g., with a gold-coated
parabolic mirror) on a sensor (e.g., a cooled MCT sensor), as shown
at 320. The sensor can create a signal, as shown at 322. The signal
can be processed using an interferometer (e.g., an FTIR
spectrometer or a Michelson interferometer that uses a spinning
mirror to split the beam and a helium laser to keep time) to create
an interferogram, as shown at 324. The interferogram can be
mathematically transformed (e.g., by taking the Fourier transform
or the fast Fourier transform) to create a spectrogram, as shown at
326. The spectrogram can be analyzed automatically (e.g., by using
a processor with multiple channels, each channel configured to use
neural network methods to indicate presence or absence of a
substance with known properties in the vapors or other substances
encountered by the radiation), as shown at 328. The result of the
analysis can be saved in a memory (e.g. recorded in a computer
memory or displayed to a user interface), as shown at 330. The
result of the analysis can be stored in a database, communicated
via a network (e.g., the Internet) to a suspect tracking website,
military command, and so forth.
[0043] In various embodiments, some or all of the method, e.g., the
mathematical transformation shown at 326 and/or the analysis of the
spectrogram shown at 328, may be performed via execution of
instructions by a computing device (e.g., one or more general or
special purpose computers, processors, ASICs, FPGAs, etc.). Some or
all of the computing device may be local and/or remote from the
system 110 and in communication with the system 110 via a computer
network (e.g., LAN, WAN, Internet). Executable instructions for
performing some or all of the method may be stored on a
computer-readable storage medium including, but not limited to,
magnetic storage media (e.g., RAM, ROM, hard drive), optical
storage media (e.g., CD-ROM, DVD), semiconductor storage media
(e.g., Flash drive), and so forth.
[0044] If the presence of a particular substance is detected, the
system 110 may provide a suitable alert or take a suitable action.
For example, a warning sound or light may be actuated, a user
interface may display information about the detected substance
(e.g., on a monitor or display), an electronic message may be
communicated (e.g., an e-mail, text message, or the like can be
sent to suitable authorities), a warning or other shot may be
fired, etc.
[0045] Reference throughout this specification to "some
embodiments" or "an embodiment" means that a particular feature,
structure or characteristic described in connection with the
embodiment is included in at least some embodiments. Thus,
appearances of the phrases "in some embodiments" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment and may refer to
one or more of the same or different embodiments. Furthermore, the
particular features, structures or characteristics can be combined
in any suitable manner, as would be apparent to one of ordinary
skill in the art from this disclosure, in one or more
embodiments.
[0046] As used in this application, the terms "comprising,"
"including," "having," and the like are synonymous and are used
inclusively, in an open-ended fashion, and do not exclude
additional elements, features, acts, operations, and so forth.
Also, the term "or" is used in its inclusive sense (and not in its
exclusive sense) so that when used, for example, to connect a list
of elements, the term "or" means one, some, or all of the elements
in the list.
[0047] Similarly, it should be appreciated that in the above
description of embodiments, various features are sometimes grouped
together in a single embodiment, figure, or description thereof for
the purpose of streamlining the disclosure and aiding in the
understanding of one or more of the various inventive aspects. This
method of disclosure, however, is not to be interpreted as
reflecting an intention that any claim require more features than
are expressly recited in that claim. Rather, inventive aspects lie
in a combination of fewer than all features of any single foregoing
disclosed embodiment.
[0048] Embodiments of the disclosed systems and methods can be used
and/or implemented with local and/or remote devices, components,
and/or modules. The term "remote" may include devices, components,
and/or modules not stored locally, for example, not accessible via
a local bus. Thus, a remote device may include a device which is
physically located in the same room and connected via a device such
as a switch or a local area network. In other situations, a remote
device may also be located in a separate geographic area, such as,
for example, in a different location, building, city, country, and
so forth.
[0049] Methods and processes described herein may be embodied in,
and partially or fully automated via, software code modules
executed by one or more general and/or special purpose computers.
The word "module" refers to logic embodied in hardware and/or
firmware, or to a collection of software instructions, possibly
having entry and exit points, written in a programming language,
such as, for example, C or C++. A software module may be compiled
and linked into an executable program, installed in a dynamically
linked library, or may be written in an interpreted programming
language such as, for example, BASIC, Perl, or Python. It will be
appreciated that software modules may be callable from other
modules or from themselves, and/or may be invoked in response to
detected events or interrupts. Software instructions may be
embedded in firmware, such as an erasable programmable read-only
memory (EPROM). It will be further appreciated that hardware
modules may be comprised of connected logic units, such as gates
and flip-flops, and/or may be comprised of programmable units, such
as programmable gate arrays, application specific integrated
circuits, and/or processors. The modules described herein are
preferably implemented as software modules, but may be represented
in hardware and/or firmware. Moreover, although in some embodiments
a module may be separately compiled, in some embodiments a module
may represent a subset of instructions of a separately compiled
program, and may not have an interface available to other logical
program units.
[0050] In certain embodiments, code modules may be implemented
and/or stored in any type of computer-readable medium or other
computer storage device. In some systems, data (and/or metadata)
input to the system, data generated by the system, and/or data used
by the system can be stored in any type of computer data
repository, such as a relational database and/or flat file system.
Any of the systems, methods, and processes described herein may
include an interface configured to permit interaction with
patients, health care practitioners, administrators, other systems,
components, programs, and so forth.
[0051] A number of applications, publications, and external
documents may be incorporated by reference herein. Any conflict or
contradiction between a statement in the body text of this
specification and a statement in any of the incorporated documents
is to be resolved in favor of the statement in the body text.
[0052] Although described in the illustrative context of certain
preferred embodiments and examples, it will be understood by those
skilled in the art that the disclosure extends beyond the
specifically described embodiments to other alternative embodiments
and/or uses and obvious modifications and equivalents. Thus, it is
intended that the scope of the claims which follow should not be
limited by the particular embodiments described above.
* * * * *