High Expectations

High-definition surveillance enhances transportation, traveler safety

• By Dave Tynan
• Mar 03, 2010

The dramatic increase in airport-security spending over the past decade has maximized traveler safety, but we still have a ways to go. Airports pose unique challenges for surveillance systems, not only due to their sharp focus on passenger safety, but also because they encompass very large spaces. In fact, nine of the top 20 largest facilities on Earth are airports.

Providing security risk mitigation using surveillance in and around airports with legacy resolution cameras requires an unmanageably large number of cameras and results in marginal forensic detail, making preventive tactics and successful investigations difficult. Many analog technologies or first-generation network video management systems installed after 9/11 are aging and are now less reliable than high-definition systems, which are based on megapixel cameras.

Airports face increased pressure to improve systems from public and governing agencies. At the same time, expenditures for upgrades continue to come under unprecedented scrutiny. This article describes five key design considerations necessary to successfully migrate or upgrade airport surveillance systems by incorporating high-definition video as a cost-effective option worthy of the most secure airports on the planet.

Address the Engine

The typical approach to updating a surveillance system involves upgrading the cameras as the first order of business. But this is not necessarily the right place to start.

Conventional systems that archive video from VGA cameras compromise quality because excessive compression eliminates detail, meaning security professionals cannot recover visually loss-less video.

Rather than tackling the expensive proposition of replacing all existing cameras, it makes more sense to first find a compression and transmission software engine that allows you to free up existing VGA cameras to maximize their performance and lower costs. This, along with analog-to-digital encoders, will allow you to preserve assets while improving video quality—without recabling new cameras.

The compression engine will be archived with video of the same quality, but the same engine also will be able to effectively manage the millions of pixels generated and captured by high-definition megapixel cameras. Complement the existing camera network by designing a hybrid system with high-definition cameras at high-traffic areas and critical views as budget allows. By doing so, you are effectively futureproofing the system, gaining the ability to scale and add HD capability over time and to ultimately migrate to 100-percent highdefi nition surveillance.

Reduce Camera Counts

With megapixel cameras, users can define the video quality by using the new industry pixels on target metric. Commercial off-the-shelf megapixel cameras are available today in 1 to 16 megapixels, allowing designers to build a fit-to-purpose system.

A 1 megapixel camera delivers 327 percent more pixels than VGA, a 3 megapixel camera delivers 924 percent more pixels and a 16 megapixel camera delivers more than 5,000 percent more. Pixels on target are calculated by dividing the width of the scene covered by the horizontal resolution of the camera. A 1,000-pixel-wide camera covering 10 feet provides a POT of 100 pixels per foot.

To positively identify a human face, a POT of 40 pixels per foot is required. A single 16 megapixel camera can cover scenes up to 120 feet wide and capture 40 pixels per foot. Achieving the same level of detail would require 50 or more conventional cameras.

Flexibility in camera resolution facilitates cost-effective system design and can significantly reduce the overall camera count in an airport system. For example, it may be fine to specify a 1 megapixel camera for check-in counters, but you may want to move up to 5 megapixel cameras for passenger gates and use 16 megapixel cameras for tarmac monitoring.

For new and expanding surveillance systems, this approach fosters cost-effective installation by reducing cabling, as well as associated labor and materials, and provides the opportunity to incorporate wireless transmission. A mix of cameras ensures the best level of detail for each application, allowing the system designer to meet detail specifications with flexibility in terms of camera costs.

Design a system that delivers a security operation with the appropriate level of detail using an economic mix of cameras. For airports, which are dealing with growing watch lists, getting the right level of detail provides a more predictable outcome from video forensics. Facial detail aids in verification and validation of incidents and provides indisputable watch list confirmation. Instantaneous identification enhances judgment and decision making and reduces response times. With the right level of detail, the potential to actually prevent incidents rises significantly.

The combination of fewer cameras, reduced labor and materials, along with falling storage cost requires system designers to compare installed costs versus component purchase costs alone.

Consider Storage an Ally

More pixels, more evidence and more detail all result in the need for more storage. Whereas once storage may have been considered the enemy, advanced systems can now actually turn storage into an ally.

A proper storage management system will include advanced tools that enable security professionals to manage available storage, including per camera data aging, maximum retention time and scheduled online backups, while taking advantage of network design. Intelligent data aging is a unique and important feature for HD surveillance storage. It allows organizations to retain recent footage at the original highest frame rate and then, after a set time, store footage trimmed to half the original frame rate. Later, it can be stored at one quarter the original frame rate for improved storage efficiency.

Look for a system that can set this behavior on a camera-by-camera basis, permitting precise control of data quality and retention periods. The return on investment for an HD video surveillance system is measured in fewer investigation hours, more successful investigations, savings due to liability mitigation and proof of compliance— not in cost per gigabyte.

Send What is Requested

Perhaps the most crucial task for an HD surveillance system is to manage the transmission and display of visual information on monitoring workstations located in the operations center, or shared remotely by associated decision makers or other agencies. The benefit of the additional detail provided by HD can be wasted by the inability of the system to transmit or process it properly.

Intelligent HD platforms use data management software to manage transmission and display using a progressive compression method. An HD data file is a deep 3-D stream that provides high forensic video value, archived and processed at the edge of a network. However, an investigator monitoring or calling up information will only view a portion of the file at any given time. By sending only the requested pixels and not the entire data stream, the monitor workstation does not become overwhelmed with processing unnecessary pixels or data. This design produces immediate savings in bandwidth for transmission and requires less processing power at the workstation level.

Fuel Advanced Analytics for Prevention

Once a robust, underlying data gathering, transmission and management system is in place, the real worth of a high-definition, digital surveillance system in an airport becomes clear—it can be digitally monitored to immediately and irrefutably detect unusual situations and associated detail, and it can even perform accurate facial detail validation. Advanced video surveillance software can more effectively monitor real-time surveillance information gathered by cameras. When the software detects an event, it can alert security professionals for immediate investigation of the situation.

Since HD video detail is far greater, judgments are more rapid and accurate, resulting in potentially reduced and resolved crises. HD surveillance also has the potential to move facial recognition software to a much higher level of accuracy and probability, given the input is now millions of pixels, compared to previous algorithms based upon VGA. The better the data quality going in, the better analytic applications can project outcome.

If the megapixel camera is equivalent to the eye, then recording, transmitting, storing and monitoring solutions can be considered the brains of an HD surveillance system. By specifying an engine that can handle the transmission, recording and analytics, airports can incrementally migrate from analog to digital high-definition systems more easily.