Video surveillance is one of the most popular security strategies that K-12 schools deploy. With the proper planning and technical knowledge, video can be an effective element of a school district’s physical-security program.
This two-part series focuses on IP video, but a great deal of analog video still is installed in various places, and advancements in high-definition analog don’t necessarily limit installers to IP video only. In this article, we’ll focus on system planning.
We would be remiss if we didn’t state upfront that it’s important for security technology deployment to be preceded by a physical-security risk assessment. This assessment ensures that the video system is aimed at areas where the maximum risk reduction can be achieved based on local unique conditions and incident history. If the owner of the project is willing to accept the risk of installing a video system without a risk assessment, you can find useful information in the Partner Alliance for Safer Schools “Safety and Security Guidelines.” For more information, go to www.securingpeople.com.
Design Considerations
Two basic principles of camera deployment are covering people and assets. Chokepoints are defined routes where people or vehicles should pass to enter a certain area. Examples include doorways, hallways and driveways. Placing cameras at chokepoints is a cost-effective way to document who entered a facility. For this function, the camera should be aimed to capture faces of entering people. Conversely, when video is used for theft-detection investigations, the camera might be aimed to see faces (and the objects being carried out) as people leave a facility.
Assets are the specific objects or areas that should be protected. Assets include physical objects, such as sensitive records and product-storage areas, as well as areas where important activities occur. These include parking lots, shipping docks or main office lobbies. Assets are defined based on the priorities of the district.
At the beginning of your system layout, you should develop a camera schedule that can be used to record critical details about that camera for installation, connection to the network, maintenance and troubleshooting throughout the life of the devices and system. You can put a lot of data into a camera schedule, but some examples are:
- Camera number (to be used when labeling the cables at the patch panel)
- Camera location and description
- Mounting surface
- What the camera monitors
- Function
- Floor or level
- Resolution
- Recorded frames per second (affects video quality, bandwidth and storage)
- Bandwidth consumed
- Total storage required for specified duration of recording (considers resolution, frame rate and percentage of time activity might occur in the scene)
- Camera type (fixed versus panning)
- Firmware version
- Password (must be changed from default)
- Termination location (where the camera cabling terminates)
You can download a sample camera schedule template at https://www.securingpeople.com/k-12-physical-security-consulting/#Resources-Video/.
Camera Function
After the general placement is agreed, one of the next steps is determining the function of the camera. Several facets are worth considering.
Typical deployment to deter criminal activity might be in parking lots or other areas where common property crimes occur in schools, such as theft or vandalism.
Many video surveillance systems in use are used strictly for forensic purposes, which is defined as “after the incident” review. Recorded video is consulted to verify what happened during an event.
When used forensically, there should be no expectation that the video will prevent an incident from happening. Careful consideration should be made as to how long it might be before an incident is discovered, and this should factor into your decision about how long to maintain the recorded video (a potentially large part of the overall system cost). Note that with IP video, footage from cameras used for different purposes can be stored for different durations to maximize video-storage resources. For instance, an incident of property damage is likely to be discovered by the vehicle owner the same day it occurs versus vandalism that occurs in some obscure area of a building. All things being equal, you would archive the parking lot camera for less time than the camera used to assist in identifying a party responsible for vandalism.
Another useful function of video is alarm assessment. For organizations that have an active security-guard operation or want to use video to verify what’s happening if an intrusion detection system activates, video can be an excellent tool to determine quickly whether an alarm is a security breach in progress or something else. When video is used this way, a “dark screen monitor” for video callup on alarm is a recommended practice. A dark-screen monitor is a dedicated monitor that doesn’t have any video displayed until an event occurs and the associated video pops up on the screen. It’s a good way to call a person’s attention to the monitor rather than unrealistically expecting someone to watch a video screen constantly.
There are times when personnel might be admitted remotely into a building or site, such as a visitor to the main office or a food-delivery driver for the kitchen. When remote admittance is required, video can allow employees to verify the identity of a person before admitting them to the building or site.
Another potential function of video is to allow for security personnel to use the system to supplement roving or directed patrols by surveying areas of the campus that might be experiencing elevated criminal activity. Exterior pan, tilt and zoom cameras can be engaged to view areas and to supplement vehicle or foot patrols, but these cameras shouldn’t move constantly. It’s easy to think that constant movement is a good practice, but many times the camera invariably will be in the wrong position when an incident occurs. Far better is to consider multiple fixed cameras or multi-imager cameras, which can provide 100 percent scene coverage 100 percent of the time.
During serious security incidents, such as an active threat inside a school building, remote video access can provide law enforcement with an ongoing assessment of the location and activities. Some valuable lessons were learned from the Parkland Commission Report and how the video system wasn’t an asset during the shooting at the Marjory Stoneman Douglas High School. A copy of that report can be found at www.securingpeople.com.
Video technology is advancing rapidly. By using various analytics solutions, a video camera can be turned into an active detection device to detect movement where there should be none or human breaches of a property.
Camera Selection
After the function of the camera is defined, you can begin to collect the environmental data that will allow you to make the proper equipment selection. For example, you should determine what quality of video you require at what distance from the camera, otherwise known as field of view versus target distance. To specify video surveillance effectively, it’s important to understand the concept of pixels per foot (PPF) or pixels per meter (PPM).
- High quality / identifying people and license plates: A standard of 40 PPF in good, stable lighting conditions is recommended for facial recognition when you deal with people you don’t know, such as a large public venue. A standard of 60–70 PPF is recommended to identify license plates.
- Moderate quality / easily see an object but not all identifying details: Manufacturers typically recommend between 20 and 40 PPF. This is achievable as long as lighting is adequate.
- Low quality / detection only: Manufacturers suggest 3–10 PPF. Generally, anything below 20 PPF will render a poor image, particularly if there are low light levels.
As an illustration of this concept, if you want to identify a person 75 feet from a camera in an area that’s 45 feet wide, these parameters will lead you to a camera that has an appropriate resolution — in this case, a 3-megapixel camera to be on the safe side. The field of view, of course, is variable and gets wider as the target is farther away from the camera, but for the purpose of design, identifying the performance required at the farthest distance will be necessary to meet minimum requirements. Anything that occurs closer to the camera might produce better results.
If these parameters are undefined, there’s a great chance that your customer will be dissatisfied when an incident occurs at the far edge of the field of view and the resolution is insufficient to make an identification.
It’s recommended to bring several cameras to the scene and take the time where possible to do a live shoot out of different cameras to allow the owner to see the results before a camera is purchased and installed.
Many free camera-design tools are available. Some examples include:
- Axis Video Design Tool – https://www.axis.com/en-us/tools/axis-design-tool
- IPVM Calculator – https://calculator.ipvm.com/
- Bosch IP Video System Design Tool – https://www.boschsecurity.com/xc/en/solutions/video-systems/tools/
It’s crucial to get these details correct. Your customer is counting on it.
Next month, we’ll discuss implementing a video surveillance system, including power considerations, bandwidth and storage and cybersecurity issues.
Frank Pisciotta, CSC, is president of Business Protection Specialists Inc., an independent security consulting firm focusing on K-12, industrial, manufacturing and corporate security program development, including video surveillance design services. He can be reached at [email protected].
