The eyes have it

For many jobs critical to homeland security, a picture can be worth a thousand words. Increasingly, such pictures come in the form of full-motion digital video, shot in real time, often from afar, then distributed to key personnel or scrutinized by software for signs of trouble.

Government interest in video — and more specifically, digital video, the technology's gold standard — is rising, even though the market is still in its infancy. The reason is simple: Applications for the technology abound.

Uses could include first responders reviewing live video of an emergency on handheld computers while rushing to the scene. Or security officials could monitor video surveillance systems that can alert them to suspicious activity at borders and airports, and near critical infrastructure such as bridges and power plants.

Digital video systems — unlike the widely deployed traditional analog or tape-based camera systems — enable agency officials to access real-time video remotely from multiple locations via a general-purpose IP data network. Although an analog system can transport only one video signal from one camera at a time, one standard copper data cable can forward images from more than 200 cameras simultaneously in a digital system.

Digital video is ideally suited for first responders because it can provide multiple views of a situation, said Mohan Trivedi, director of the Computer Vision and Robotics Research Laboratory at the University of California, San Diego. Trivedi is spearheading research funded by the Defense Department to study Distributed Interactive Video Arrays, a system linking multiple cameras that track people or objects as they move.

On Sept. 11, 2001, "in New York and at the Pentagon, many of the first responders had much less of a feel for the overall damage than you and I who were watching television," Trivedi said. "We were able to see multiperspective, multiresolution images. [With digital video] the first responders can have access to tap into these customized views of different areas of the perimeter."

Detroit's Metropolitan Airport has been a pioneer in using digital video to augment security. Airport officials use digital video and software to intelligently sift through massive amounts of video for suspicious activity, such as unattended baggage or a car parked too long at the curb, said Mark Wellman, president of integrator Camtronics Communication Co., which designed and installed the system.

"Remote assessment is the key element here, especially now, when we have a hundred times more reviewing and patrolling to do than before" Sept. 11, he said. "With so much activity and an eye on managing people and manpower, we have a force multiplier that has been brought into the picture that is far more complete than we had in prior technologies. Officers responding to conditions don't need to rely on a dispatcher's description of a condition," because they can access video themselves.

Washington, D.C., police have deployed analog cameras and video servers from Axis Communications. The servers convert the cameras' analog signal into digital form, enabling police to share recorded images with other agencies using an IP-based computer network, said Axis' James Marcella.

"Now they can send them out as an e-mail attachment, or just allow other agencies to come in and view their feeds" via a wide-area network, he said. "We often hear that one department can't share information with another because of disparate systems. The pinnacle of sharing video is a digital video system."

Axis also sells network-attached digital cameras with an Ethernet port that can be assigned an IP address. The cameras can capture and transmit live images directly via an IP network. Users can manage the digital cameras remotely via a Web browser.

Video Surveillance

Although digital video enables first responders to glimpse a scene before arriving, other agencies use the technology as part of routine field operations to enforce security policies. VistaScape Security Systems' Security Data Management System, for example, lets users define restricted zones and set up rules for triggering alarms.

Data captured from field cameras is processed and then formatted into Extensible Markup Language (XML) and encrypted. Those records are fused into a single data model that can be retrieved and displayed by end users as a virtual 3-D model.

"To enforce policy, you have to have a sensing system that can capture that kind of information and compare the real-world information to the policy and then recommend action based upon deviation from policy," said Glenn McGonnigle, VistaScape's chief executive officer.

In addition, because the system uses TCP/IP to move data, users need not install a closed-loop proprietary system like those required with analog video, McGonnigle added. Nor do they necessarily have to upgrade to special high-speed networks for the digital cameras.

"The customer only views live video when there is an event worth looking at," he said. "They don't have to run a high-speed network like fiber, because 90 percent of the time, the event information is coming out as these small XML records

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