VIEWS: 15 PAGES: 4 CATEGORY: Social Sciences POSTED ON: 7/14/2010
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.
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
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