What's Around The Bend

Dealing with transit security issues in real time

• By Anthony Incorvati
• Jul 01, 2012

Transit authorities face security problems on an ongoing basis—everything from graffiti artists and pickpockets to precious metal theft and fuel siphoning. For years now, security experts have relied on camera installations for incident control, but too often surveillance video has been used more as a forensic tool to investigate the aftermath rather than as a practical tool to detect and possibly prevent incidents from happening.

The drawback is pretty obvious. By the time the relevant video is located and handed to authorities, the suspects are gone. And oftentimes, because of poor lighting conditions and outdated technologies, the video is too grainy to provide any usable details such as facial features and clothing color to assist in pursuit and apprehension. However, recent innovations in network video are reversing the tide by giving transit authorities real-time access to high-image-quality video streams.

From Forensic to Real-time

Moving from forensic to real-time security benefits transit systems, airports and even seaports on a number of levels. Handling incidents quickly is an effective way to boost passenger and staff confidence in transit safety. By being preemptive, transit property owners avoid the costly repercussions of vandalism, graffiti, metal theft and other nefarious acts—a savings that goes directly to the bottom line. Maybe more importantly, using the cameras to proactively monitor transit operations minimizes revenue losses due to disruption of service.

Some of the new network camera technologies on the market are bridging the noticeable gaps in coverage that previously frustrated transit authorities.

Of course, HDTV-quality network cameras continue to be an extremely popular purchase for all surveillance users, including those in the transportation market. High-resolution, true-color-fidelity video is replacing grainy analog images, resulting in a far greater percentage of positive identifications of people and objects. However, that image quality comes at a cost: higher pixel counts traditionally meant lower quality in poor and difficult lighting. But that’s where today’s IP imaging innovation shines.

Surveillance When Conditions are Less than Optimal

Transit system environments on the whole present a major challenge for video surveillance cameras—mainly because they’re plagued with poor or widely fluctuating lighting conditions that change in an instant. Historically, transit authorities accepted the fact that, without a massive artificial lighting investment, certain areas—yards and depots, tunnels, guideways, tracks and sometimes platforms and stations—simply couldn’t be monitored by video cameras.

With the introduction of three innovative network camera technologies, that’s no longer the case.

Low light. Lightfinder technology represents the latest advancement in extremely low-light surveillance. It works in concert with a network camera’s sensor and lens to find light in a scene that it can use to stream color video even at night. Sophisticated image processing software sets the degree of filtering and sharpening to capture the best image possible.

Highly sensitive to low light, a network camera enhanced with Lightfinder can maintain tight focus, with minimal noise, from dusk to dawn as well as in full sunlight.

But the crowning achievement is that unlike typical day/night cameras that switch to black-and-white mode in low light, Lightfinder cameras record in true, lifelike color fidelity across the illumination spectrum.

Widely fluctuating light. Wide Dynamic Range (WDR) technology incorporates techniques for handling a wide range of lighting conditions within a single scene, such as extremely bright and darkly shadowed corners or backlit situations where a person is standing between the sun and the camera. In those scenes, a standard surveillance camera would inevitably produce an image of a sun-washed person or objects in the dark areas barely visible. A network camera equipped with WDR, on the other hand, combines different exposures to different objects within a scene, depending on the prevailing light to ensure nearly uniform visibility across the field of view.

Total darkness or haze. Unlike day/night cameras that focus on recognizing images in the visible light spectrum, advanced thermal imaging cameras detect wavelengths far into the infrared spectrum. Analog thermal cameras have been around for years to detect the heat signatures emitted by all people and objects. These military-grade cameras once cost tens of thousands of dollars. Today, true thermal network cameras are an affordable option that can be easily integrated into a transit surveillance network to detect trespassers walking alongside the track at night or inside a dark tunnel.

Revealing Previously Hidden Activity

If used on their own or in conjunction with each other, these three technologies open up a whole new realm of surveillance coverage that wasn’t possible with older camera systems:

On the platforms and in the stations. While transit authorities made a concerted effort to blanket platforms and stations with video surveillance coverage, camera technology fell short when it came to piercing shadowy corners and alcoves. Sunlight glaring off the glass on outdoor platforms and headlights of oncoming trains taxed the abilities of the cameras to deliver quality video. But with Lightfinder, WDR and thermal imaging cameras augmenting their camera deployment, transit security can capture clear, useable images across the visual spectrum. For instance, when used at night, Lightfinder can distinguish between a red or black hooded sweatshirt and a blue or green backpack worn by someone standing on the platform. Grayscale guesses of old analog, black-and-white CCTV systems will become a thing of the past.

By the tunnels, guideways and tracks. Tunnel and track security has been especially problematic, given the widely exposed and open spaces that are unprotected from the elements with little or no illumination. Installing light poles and fixtures over miles of track is often too costly. Even guards patrolling the area can’t be everywhere at once, so vulnerable tunnels and sections of track are left unobserved for extended periods of time. Thermal imaging cameras can play a major role in securing these areas because they rely on heat detection rather than visible light to “see” what’s going on.

They can detect what conventional cameras miss and alert security to the presence of objects left on or near the tracks or trespassers on grade crossings. In daylight hours, WDR cameras can reveal what’s happening both inside the tunnel and at the entrance.

Inside the rail yards and depots. While personal assaults and theft rank high on the list of transit security threats, protection of corporate assets is another major area of concern. Railcars, subway coaches and busses parked in poorly lit yards and depots are especially vulnerable to vandalism and other acts of mischief. Fuel farms and supply depots offer their own allure to pilferers, coordinated gangs of criminals or even dishonest employees seeking to siphon gas or steal precious metals like copper. While perimeter fences and guards patrolling the area provide deterrence, Lightfinder and thermal imaging cameras give security the critical night vision to “see” into the shadows, eliminating the cover-ofdarkness advantage that offenders use to mask their activities.

Using Video for Operational Intelligence

Another trend gaining momentum in the transit arena is to expand the use of surveillance video to improve operations. Applying analytic technology such as automatic people counting (APC) helps transportation managers track traffic patterns both inside and outside a station to improve transit schedules and minimize passenger commute time. Monitoring the flow of people through entrances, exits and typically congested areas such as hallways, parking lots and walkways gives security personnel insight into pedestrian traffic and the ability to anticipate and react quickly to any incident or slowdown in service

This video analysis also helps station managers optimize security-staffing levels to handle crowds at peak travel times.

Integrating Multiple Systems Under One Umbrella

While new camera technologies like Lightfinder, WDR and thermal imaging certainly improve surveillance coverage, real success is often achieved when network video is part of an entire portfolio of physical security tools— from intrusion detection to access control to motion/audio sensors.

To avoid the chaos of trying to filter massive amounts of time-sensitive information from all these separate subsystems simultaneously, application developers are introducing new Physical Security Information Management (PSIM) systems to provide transit authorities a way to intelligently integrate data from disparate sources in real time within a single command center. Designed to provide an easy-to-read dashboard that prioritizes data according to pre-established criteria, PSIM systems bring the most important incidents to the foreground—like a trip-wire alert linked to video of an intruder trying to scale a fence after hours or a door-ajar alert tied to video of a vagrant trying to jimmy open a locked accessway near a station platform. This enables transit security to quickly address and resolve a problem before it escalates.

What’s Around the Bend?

Based on the continued R&D investment in the technology, IP innovation will continue on a sharp trajectory. Light sensitivity continues to become even more acute while HDTV-quality resolution and usage improves across an ever-wider dynamic range. We’re even seeing network cameras with the versatility to stream in 9:16 corridor format (“portrait” as opposed to “landscape”), a feature that’s ideal for covering long concourse areas, people movers, tunnels and station platforms without wasting pixels.

With the enormous advances manufacturers are achieving in chip technology and processing power, the potential for third-party development of video analytic applications specifically geared to the needs of the transportation industry is likely the next phase of innovation. With transit authorities adopting network video for more of their installations, it’s exciting to think of all the intriguing possibilities that are just around the bend.

This article originally appeared in the Security Products Magazine - July 2012 issue of Security Today.