Going Thermal

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Going Thermal Powered By Docstoc
					                                                 Video Surveillance




             Going Thermal
                        As features are enhanced and prices decline,
                        the technology is finding wider application
                                             By Randall R. Nason, PE, CPP
     he increasing emphasis on homeland          However, thermal imaging cameras           pass the constructed video image to any



T    security — especially as it relates
     to ports and other large sections of
     critical infrastructure — has result-
     ed in the development of technologi-
cal tools that have enabled end-users to
address security-related problems that
were seemingly beyond their reach a
                                              stand out as a particular class of tech-
                                              nology that enables a new and effective
                                              approach to classic intrusion detection
                                              heat signature. Those of us familiar with
                                              traditional CCTV cameras that operate
                                              in the visible light spectrum expect the
                                              thermal imaging cameras (often referred
                                                                                            of the current CCTV viewing and storage
                                                                                            devices. However, the changes from the
                                                                                            expected model are anything but subtle.
                                                                                               The essential characteristic of thermal
                                                                                            imaging devices is that they operate by
                                                                                            detecting the heat emitted by an object.
                                                                                            This object could be a human body or
decade ago. Examples of these technolog-      to as infrared or IR cameras) to simply be    a car whose engine is or has been run-
ical advances are recognizable in any cur-    an extension of the infrared sensitivity in   ning. The emitted heat signature by an
rent security system design and include       modern digital cameras. At first glance,      object can be attenuated but normally
video analytics, IP-addressable security      both cameras receive electromagnetic          not completely eliminated by fog, smoke,
devices and Power over Ethernet enabled       radiation from a source, detect and pro-      rain or other obscurants. This enables
by IEEE Standard 802.3af.                     cess it with a microelectronic chip, and      these devices to see the thermal image


30          SECURITY TECHNOLOGY EXECUTIVE • January 2010
even when the visible light image is com-      nology cameras in low light (not no light)              of facial or body structure in the image
pletely obscured. Examples of this are         at night with the IR cut filter removed.                precludes any further analysis leading
illustrated in the photos below where the         Thermal imaging cameras operate in                   to identification of a specific individual.
visible and thermal images are compared        a different portion of the spectrum using               While resolutions of 4 CIF and higher are
side-by-side.                                  different detection technologies. Thermal               available, most cameras deployed today
                                               imaging cameras operating in the long                   for security applications have typical res-
Light Spectrum                                 wavelength range use a chip called a                    olutions in the CIF range.
   The chart on Page 32 illustrates the        microbolometer. Infrared radiation strikes                 Coupled with the fact that the image is
electromagnetic spectrum, ranging from         the detector material in the microbo-                   in black-and-white, the resulting digital
the far infrared to the far ultraviolet. The   lometer, causing its temperature to rise,               image file is much smaller than secu-
world in which you and I as security prac-     thus changing i
				
DOCUMENT INFO
Description: The chart on Page 32 illustrates the electromagnetic spectrum, ranging from the far infrared to the far ultraviolet. The world in which you and I as security practitioners tend to operate in is the visible light spectrum - with wavelengths ranging from approximately .4 to .7 micrometers (microns). Thermal imaging cameras work in the infrared range with wavelengths ranging from approximately 1 micrometer to more than 13.5 microns.
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