Force multiplier: PSIM leverages video surveillance networks in Baltimore

Baltimore’s CitiWatch video surveillance program has expanded over the past eight years from an initial installation of 50 standalone cameras to more than 600 networked closed-circuit cameras, which provide live video feeds around the clock. In addition, the program has access to about a thousand additional cameras operated by more than 50 federal, state, city and private organizations.


Tech, tactics behind CitiWatch’s large-scale video surveillance system

A video surveillance system that combines thousands of cameras requires more than technology to be effective. Read more.

“Our mission is to make sure the crime doesn’t occur,” said Lt. Sam Hood, CitiWatch’s director of law enforcement operations for Baltimore Police Department. “We proactively watch our cameras.”

By using GIS crime mapping data to identify hot spots and watching for telltale signs of trouble before they are reported by a call to 911, “we can probably stop a situation before it occurs,” he said.

“This is a force multiplier,” Hood said. The addition of technology to the system has made it more cost-effective as it has expanded. The cost to operate the entire system today is less than the cost of managing and retrieving video recordings from the initial 50 pod cameras in 2005, Hood said.

A major challenge in such a mission is making sense of the large volumes of data generated by these networks. It can be hard to keep your eye on the ball when there are hundreds of balls in play at a time. Training and experience helps. CitiWatch primarily uses retired police officers to monitor camera feeds and communicate with cops on the streets. But the glue that holds the system together is a Physical Security Information Management (PSIM) system from VidSys that integrates feeds from disparate legacy networks and then analyzes and correlates the data.

“We’re all in one common operating picture,” Hood said. The different organizations each retain control of their own assets, but “we’re able to access each other’s information.”

PSIM is a broad term that means different things to different people. Although it focuses on physical security rather than cybersecurity, the two domains can be integrated, and PSIM ultimately relies on information technology to bring everything together.

“It is software technology that converts data into useful information,” said James Chong, VidSys founder and CTO. “That is the essence of PSIM.”

Running on a server in the CitiWatch command center, the VidShield component of the system standardizes incoming data and the RiskShield software analyzes it according to policies set by the owner, organizing events according to type and geographic location to identify incidents that might require police attention. Incidents are displayed on a browser-based dashboard, called a situation summary page, which can include links to standard response procedures and allow automatic or manual control of video feeds to follow the action.

By relying on policies for evaluating events according to rules set by the user rather than dealing with a raw video stream, a single VidSys PSIM server can support a large client architecture, Chong said. “We don’t do the heavy lifting until a criterion is met,” he said.

CitiWatch began in 2005 under then-mayor Martin O’Malley (now Maryland governor) with 50 un-networked camera pods, each with its own digital recorder. Although used for law enforcement and staffed in part by police, CitiWatch is a separate public-private partnership and not a part of the police department. It is funded in part by the Homeland Security Department and also with city and private funds. This structure makes it easier to incorporate non-city data sources, some owned by private organizations, and also helps to isolate liability in the event of lawsuits alleging privacy violations or other missteps.

There was no real-time monitoring when the initial cameras were installed. Video recordings were retrieved from the cameras for investigation after an incident. The system grew, and by 2007 the city began networking its closed-circuit cameras to allow monitoring. Crime in areas monitored by video dropped by 25 percent, said Hood.

“We’ve been putting in cameras all the time,” Hood said. An additional 200 closed-circuit cameras were installed in 2012, and the CitiWatch system now incorporates 635, using the DVTEL video management system.

CitiWatch also has access to 597 cameras from the Maryland State Highway Administration, 140 owned by the Baltimore City Department of Transportation as well as others operated by the Baltimore Metropolitan Transit Authority; the Maryland Transit Administration, which runs the city’s subway, light rail and bus systems; and a host of federal and local agencies operating in the city.

These systems are owned and operated independently of each other and are not standardized. The CitiWatch cameras, for instance, operate at a rate of from 15 to 30 frames per second while some others run as slow as five frames per second. The need to get a common view from this disparate collection led to the adoption of a PSIM system in 2010.

“We wanted someone who could leverage and integrate legacy systems,” Hood said.

VidSys filters data according to time, location, duration, frequency and type to determine significance. A geospatial engine and a policy engine lets users define the parameters for defining an incident, based on the alerts and other information a camera or other sensor sends. A single alarm or activity caught on camera might not be significant by itself. But when coupled with other information from the same or nearby locations at the same time they could trigger an alert on the situation summary page, warning the person minding the monitor as to what appears to be happening while identifying other cameras or sensors in the area and providing an action plan.

Despite the large amounts of data produced by the video, scaling is not a problem for VidSys. It relies on the intelligence built into the video systems for recognizing events that have been defined by users. The VidSys system looks at and correlates these events rather than raw video data.

“The PSIM sits on top of all of these systems, it doesn’t replace them,” Chong said. “We’re handling a lot less data than many of the subsystems would on their own.”

This means an organization that already has its sensor systems in place also has put in the necessary infrastructure. “The big infrastructure challenge is on the video side,” Chong said. “Video is a bandwidth hog.”

The VidSys PSIM not only is used for day-to-day public safety operations in Baltimore, but also provides a platform for securing special events, such as the Grand Prix of Baltimore at which the system was field tested in September 2011. Other major events where it has been used include the Preakness and commemorative events for the War of 1812 bicentennial.

About the Author

William Jackson is a Maryland-based freelance writer.


  • Records management: Look beyond the NARA mandates

    Pandemic tests electronic records management

    Between the rush enable more virtual collaboration, stalled digitization of archived records and managing records that reside in datasets, records management executives are sorting through new challenges.

  • boy learning at home (Travelpixs/

    Tucson’s community wireless bridges the digital divide

    The city built cell sites at government-owned facilities such as fire departments and libraries that were already connected to Tucson’s existing fiber backbone.

Stay Connected