video analytics

Outsmart the Outdoors

Nuisance alarms can minimize the benefits of video analytics

Proponents of video analytics claim the technology can boost the productivity of security staff by alerting them to take action in the event an incident occurs according to predetermined rules. In theory, this enables fewer officers to oversee larger coverage areas by freeing them from perpetually watching an increasing number of video displays and make intelligent response decisions when security violations occur. And for many indoor surveillance applications, this is often the case.

When it comes to outdoor surveillance, too often, the reality is different. In many cases, the security officer who was supposed to be more efficient now spends his time dealing with nuisance alarms when a gust of wind or a change in lighting triggers an alarm. As a result, officers come to distrust the system and may tune down the detection sensitivity or even turn off the alarms altogether.

Some facilities deal with hundreds of nuisance alarms every week. One reason is that video analytics is often used in outdoors applications for which they weren't designed.

The key to eliminating nuisance alarms in outdoor applications is to use technology properly designed for the outdoors rather than misapplying analytics intended for more controlled indoor surroundings. Using intelligent video to secure large outdoor venues requires specific technologies like sufficient onboard camera processing power to overcome lighting and weather issues, accurately detect and track legitimate targets from extraneous surrounding motion and clutter, and employ geographic information system coordinates to determine a target's location, size and velocity. Applying the appropriate technology to the task enables the full realization of the long-promised benefits of intelligent video and delivers new levels of efficiency for the $100 billion security guard market.

Outdoors vs. Indoors

In addition to large coverage areas typically associated with outdoor venues, there are many environmental influencers that need to be addressed. Changing lighting conditions and sources of motion caused by weather or vibrations can wreak havoc with conventional indoor detection software when applied outdoors. To cover expansive outdoor areas, cameras are often mounted on poles or rooftops, where even slight winds can cause vibrations, impacting detection accuracy. Other problems include landscape clutter, reflections and even ripples in water, along with random video "noise" that can conceal targets of interest or simply cause cameras to ignore them. All of these problems are magnified when attempting to detect targets that vary greatly in size across large fields of view.

Indoors, a camera sees a limited field of view in typically controlled surroundings. It's a mistake to apply the same technologies to monitor critical infrastructure applications such as transportation, energy, utilities or large campuses where conditions are continually changing.

The economics of covering large outdoor areas also are different. For example, a standard metric used to justify purchases and total cost of ownership for indoor applications is often calculated in terms of cost per camera. In contrast, covering large outdoor venues requires the creation of an outdoor surveillance infrastructure, including architectural design, permits, construction, trenching, camera poles, network connectivity, video display and storage.

The economic measure needs to change from cost per camera to accurate coverage per dollar. Cameras for outdoor applications must cover large areas and capture accurate information over long distances to achieve security objectives, minimize nuisance alarms and help contain infrastructure costs. They also need to be built to withstand extreme environmental conditions such as rain, snow and humidity.

A Technology Solution

Although outdoor video surveillance applications are challenging, it is possible to deploy automated outdoor systems to deliver high-accuracy detection of targets over a large area while greatly reducing nuisance alarms. Such an approach unlocks the full capability of intelligent video for use outdoors and as a guard multiplier for detecting, locating and assessing threats in real time.

To achieve success outdoors, intelligent camera systems need to integrate the necessary processing power at the edge to eliminate camera motion for accurate detection and to remove motion as a source of nuisance alarms. It is diffi cult for video analytics software to tell if an intruder has entered into view if the whole scene is moving due to wind.

Sufficient in-camera processing also can eliminate water and tree motion as a source of nuisance alarms and dynamically correct lighting to detect events that would otherwise be missed. Additional environmental factors that need to be addressed in the processing chain include the sun moving across the sky, clouds constantly in motion and shadows moving through a scene.

Another important feature for outdoor camera systems is the need to provide accurate location/positioning information to aid with threat assessment and to ensure a rapid response. Systems employing GIS-based analytics have the ability to superimpose the threat location directly on a map of the facility, while utilizing this information to set security rules based on target size and velocity. GIS information also can enable automatic positioning of a PTZ camera to provide an up-close view of a target—particularly important in large outdoor areas—and highly detailed images for forensic investigations.

Applying the right technologies to video surveillance systems can transform the performance and economics of outdoor security. Reductions in design, construction and installation costs also are possible when truly intelligent long-range cameras provide wide-area coverage with accurate data. The resulting solution will be trustworthy, drastically reduce nuisance alarms and represent a truly cost-effective surveillance technology for high-security applications.

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