Whether as standalone network-connected video servers or critical elements of an Internet Protocol-based video surveillance system, network video recorders are revolutionizing the capture and distribution of law enforcement video. As such they are being utilized in a range of surveillance systems across the country, from monitoring overly enthusiastic fans following a sports teams’ big win, to defusing bombs at a safe distance with the maximum amount of teamwork.
Like digital video recorders that have found their way into American homes, the NVR is a digital device that records and plays back videos. Unlike DVRs, NVRs are designed for connection into, and control via, an Internet Protocol (IP) network. That connection makes it easy for NVRs to capture signals carried on the network from IP-based video cameras or Web-based video streams, and to serve them wherever they are needed.
NVRs can even be configured to seek and then connect to whatever video feeds exist on the network, automatically. That makes adding them relatively straightforward, and helps when a law enforcement agency wants to record video shot by IP-based surveillance cameras (wired or wireless).
“I typically run into NVRs and DVRs in the field when I have to recover video related to a criminal case, which is most of what I do,” said Detective M.T. Brown of the Lawrence, Kan., Police Department (LKPD).
A number of companies make NVRs, such as VBrick Systems Inc. and QNAP Systems Inc.
NVR In Action
For law enforcement and other public safety agencies, NVRs are most useful when integrated in an end-to-end video surveillance solution. LKPD primarily uses its NVRs in dedicated undercover vehicles, or installed at a remote location, Brown said.
The LKPD’s most notable installation of surveillance technology occurs when the University of Kansas basketball team reaches the Final Four of the National Collegiate Athletic Association Basketball Championship, “as they have
A VBrick Systems Inc. 7000 Series Encoder
a habit of doing,” he said. “In order to offer command a live view of down- town Lawrence, which thousands of people descend upon in a very short amount of time following a KU win late in the tournament, IP cameras are installed throughout the downtown area.”
“Some of the cameras are installed in a courthouse building adjacent to the command center, where we can easily hard wire to our county’s network and stream the data to the command center,” Brown said. “IP cameras are also installed in the downtown area, where we do not have a network.”
NVRs are also a key component in the Bomb Squad response vehicle of the Arlington County Fire Department (ACFD) in Virginia. Built into a heavy-duty, high-capacity Rosenbauer fire engine chassis, the bomb squad’s truck carries two of its own remotely controlled, video-enabled bomb disposal robots, and has the capacity to control up to three more (by wired cable or wireless). The analog video captured by the robots’ cameras, plus a mast-mounted camera on top of the bomb squad’s truck, is converted into digital, stored and then transmitted onto the truck’s internal and external monitors and over the air to headquarters using NVRs, encoders and other devices made by VBrick Systems Inc.
“With our NVR we can record video to CD-ROM or USB key, or stream it live to share with other agencies,” said the ACFD’s Capt. Justin Scott, the man in charge of the bomb squad. “We can also use the video to provide situational awareness for incident commanders and other agencies when we are rendering a suspicious package or device safe,” he said.
In addition, after an incident is concluded, the recorded video can be used for review, teaching and archiving, said Scott, who credits VBrick for providing the new sharing ability.
“With NVRs and their ability to transmit video over IP, first responders can now share what they see with everyone who needs to see it in real time,” added Greg Zweig, VBrick System’s director of corporate marketing. “So, whether it’s the police in their cruisers nearby or the top brass back at headquarters, the video is available to them all.”
Moreover, because NVRs integrate quickly with IP-based video cameras they are easy to include in a covert video surveillance system, including those who use wireless to watch suspects on their own turf.
“We are generally at the mercy of our targets as to where our cameras are going to be set up,” said Brown. “This almost dictates an IP camera/wireless network/NVR configuration, unless you can lure the target to a prewired location.”
Adding NVRs To An Arsenal
The many advantages offered by NVRs make them an essential tool for 21st century law-enforcement surveillance. Although most police departments do not have the budgets to replace their existing video recording system with NVRs all at once, this does not have to be a major issue. NVRs can be integrated into existing video networks, albeit with some provision for converting any analog video inputs into digital.
In addition, NVRs are gaining in popularity as Power over Ethernet (PoE)-powered IP cameras become readily
QNAP Systems Inc.’s VS-2012 VioStar NVR
available, Brown said. That enables installers to run a single network cable to a camera so it can receive a signal that powers the camera as opposed to a coax cable and power cable being run to a traditional analog camera.
The NVRs produced by QNAP are “compatible with over 1,200 IP camera models from most major IP camera manufacturers,” said Erick Oliveros, the company’s marketing manager. QNAP’s NVRs offer real-time monitoring and recording (video/audio) from multiple IP cameras (up to 16 channels) in encoded video formats such as H.264, MPEG-4, M-JPEG, and MxPEG. The “e-recorded” video is searchable by date and time, timeline and event, and it can be monitored live over a Windows PDA phone powered by Vmobile Technologies Inc.
For law enforcement the most effective place to add NVRs is in those areas of the surveillance frame- work where speed of video access and ease of sharing are key. For instance, in an analog-based system, the final video output could be converted into digital and then fed into an NVR. This would make the footage available to everyone else on the department’s network in a form that could be viewed on a range of platforms including PCs, smartphones and in-car laptops/tablets. Over time, more of the system’s analog elements can be replaced with digital, until the last link of the video capture chain, the cameras, are switched for IP-based digital models.
As for the actual setup, the NVR appliance generally is plug-and-play, said Dean Brown, another LKPD detective and Det. M.T. Brown’s brother. “To connect it to cameras, and to make sure you can access the NVR over the Internet, a basic understanding of TCP/IP networking (networking protocol used for the Internet and most local area networks) will be required,” he said.
Once an NVR is in place, management of the device is generally easy since most NVRs operate on a overwrite cycle, he added. “They will record until they are full, then overwrite the oldest data.”