Your CCTV Can't See in the Dark

Criminals are a varied bunch. Their intelligence levels cover a wide spectrum, but, regardless of their IQ, most criminals will not try to break into the average facility in broad daylight. The night offers more cover, both for the infiltration and...

Often, electric lighting is considered imperative for frequently visited, controlled areas. But lights are indiscriminate, offering the same level of illumination to intruders that they offer to security professionals. This can make lighting and day/night cameras ineffective for some types of facility security.

CCTV Systems with Infrared Illumination
Infrared sensitive cameras (most black-and-white CCD units) are used in CCTV systems all over the world. This type of specialized lighting is the first of the more sophisticated night viewing solutions. Infrared-sensitive cameras require illumination, either visible or IR, to work in semi or complete darkness, and they get this illumination with IR lamps. There are several types of infrared illuminators available. Each has its place and purpose. Varieties include LED array, halogen and laser.

LED array technology is small, inexpensive, uses a low level of power and is widely available. The first drawback is that it illuminates only very short distances (15 to 300 feet average) and can be degraded significantly by certain types of weather.

IR lamp technology offers increased illumination distance, but can be expensive, is physically large, uses high levels of power and is degraded by weather. Halogen technology also requires annual maintenance as the bulbs deteriorate.

Laser technology offers the greatest illumination distance of the three types and sees through most types of weather, but those capabilities make laser solutions expensive. In addition to being cost prohibitive, laser technology is very large, uses extensive amounts of power, has a narrow field of illumination, is unsafe to the eye and is available primarily for military applications. Regardless of the type of illumination, each of these cameras measures the contrast in reflected light and reflected near IR. Reflected energy depends on the color and sheen of objects in the field of view. As discussed, for all types of illumination, range is a key factor in the performance of a camera using IR illumination. For CCTV applications with infrared illumination, lighting an entire coastline with lights or illuminators to see even 1,000 feet is not cost effective and would most likely prove to be prohibitively expensive and logistically difficult to maintain.

Image Intensification
Image intensification, another sophisticated type of illumination, works by amplifying the ambient light of a scene (at the face of the imager or CCD) and, therefore, must have some minimal source of light to be effective. Image intensification is one of the most widely known of the night vision systems. The three major drawbacks of such cameras are 1) upfront cost of the camera-ranging from $3,500 to $7,000 each; 2) long-term maintenance-average life expectancy of the intensifier/CCD setup is two to four years; 3) these cameras require at least starlight to full moon to operate, and such lighting must be in the visible range. IR lighting will not work.

The Future of Thermal Imaging in Security
Thermal imaging's popularity among security managers continues to increase. As the volume of installed systems grows, price points are likely to decrease. This bodes well for facilities of all types, but it is particularly good news for facilities located in areas where other types of security cameras and lighting systems have been impractical or ineffective.

Technological advances in thermal imaging technology also are likely to increase its use as part of overall security solutions. As the adoption of thermal imaging technology increases, it will continue to be integrated to work with a host of security applications, including video motion detection, access control systems and specialized software. Also, its ability to see over greater distances will increase in the years to come, making the technology even more effective for wide range security applications.

Ultimately, this increased level of security is beneficial to everyone, except, of course, a criminal.

John Love is the director of security and homeland security market development for Raytheon Infrared. Mr. Love has more than 25 years of experience with thermal imaging products and markets. He has been with Raytheon and Texas Instruments since 1978 in a variety of technical, product development, sales and account management roles.