Digital Video Surveillance & Private Schools
By: Linda Richardson
Why are private schools safer? For one, they tend to be smaller and more manageable, but a key factor is that many private schools either have or are in the process of obtaining video surveillance systems in order to address school safety issues. The best thing about security cameras is the deterrence factor they introduce to outsiders who do not belong on campus and to students and employees who do.
After a school has decided to install a video surveillance system, they are faced with two fundamental issues: choosing the best system for the school and installing the system so that it maximizes its utility (such as with proper camera placement). Chances are that the majority of the cost of video surveillance implementations is the purchase and installation of the cameras themselves.
Choosing the Right Equipment
Once you have determined your particular camera requirements, you can select the appropriate type of cameras. There are several classifications under which an individual camera will fall.
1. Configuration
Dome cameras provide a discreet option especially when the dome enclosure is tinted to hide the camera from view. Vandal-proof domes are also important when the cameras are easily reached, such as in a hallway. Bullet cameras are usually longer cylindrical enclosures that are often installed under eaves or in corners. Pinhole cameras are usually hidden in innocuous enclosures, such as smoke detectors. PTZ (Pan Tilt Zoom) cameras allow the cameras field of view to be panned or zoomed in on. PTZ cameras are most often used for live viewing in that the user can control the direction and amount of zoom on the camera. With camera presets, you can have a camera cycle through several preset positions.
2. Exterior vs. Interior
Both exterior and interior cameras are available in the above described configurations (Dome, Box/Bullet, PTZ and Pinhole). However, for exterior use, with many of these cameras, you will need an enclosure, which will protect the camera against extreme hot and cold temperatures, as well as other outdoor elements, such as rain, snow, etc.
3. Resolution
One of the most important aspects of cameras is the resolution, which determines the clarity of the images captured. It's a simple rule of thumb: the higher the camera resolution, the better the clarity. Megapixel cameras are examples of cameras with extremely high resolution. Although there are some analog megapixel cameras, the majority are IP-based. IP-based cameras connect through your existing IP network rather than through coax cabling. While IP-based cameras are frequently more expensive than analog cameras, their costs may be offset if you have an existing high-speed network in your facility.
4. Lenses
When you purchase a camera, many – but not all – come with lenses, which are also a very important aspect of the camera. Typically, the requirement for lenses is driven by the distance from the camera to the scene that will be viewed. For those who are familiar with standard cameras, the principals are the same: the lower the millimeter designation, the wider the viewing angle. Varifocal lenses can be adjusted, and auto iris lenses will automatically change the lens aperture according to lighting. Auto iris lenses are recommended for outdoor applications due to lighting changes that occur throughout the day.
Other issues to consider when selecting the right camera equipment include the lux rating of the camera (how sensitive it is to light), wireless, and wired. Although a wireless camera may appear to be an easy solution, most wireless networks do not provide sufficient bandwidth to carry high-quality video images.
Choosing the Right Location
You don't need to video every square inch of a school to make it safe. That's expensive and not particularly effective. Before you being a video surveillance project at your campus, perform a careful walkthrough to determine the best location for your cameras. What are some key areas?
1. Entrances
Having cameras at all entrances gives you a recorded image of every single person who has entered or exited your school.
2. High-Value School Equipment & Sensitive Data
Most school campuses have expensive equipment, such as computers and vending machines, as well as records that contain sensitive and private student data. A video surveillance system can be set to record "motion zones," which will record when computers are removed or even when files that hold school petty cash funds or confidential student records, etc., are opened.
3. Student Congregation Areas
Keeping an eye on students in a contained classroom is an easier task than when they congregate in halls or courtyards in between classes or before and after school. Cameras in these areas act as a deterrent to misbehavior, but also will record and store images or incidents including fights or other altercations.
What are some other considerations for video surveillance system implementation?
When placing a camera, lighting needs to be taken into account, which means looking at both day and night conditions, as well as for things that can change throughout the day. The most common error when not taking lighting into consideration is backlighting. Backlighting issues happen when there is a strong light source behind the subject, which causes a person to appear to be a silhouette – rendering them unrecognizable on recorded images. Exterior doors tend to be the worst offenders: a person walks through the door and strong sunlight backlights the person. If this later becomes an area you want to review on your recorded video images, you will likely not be able to identify the person.
If you have a controlled and guarded entrance to your school grounds, you may want to record every vehicle that enters. For any kind of identification to work, the object you are attempting to identify needs to be a very large part of the image. This means that facial and license plate recognition might be fairly hard to accomplish. When attempting to do either, you want to look for choke points that force the person or vehicle into very small spaces and force them to move slowly. This will make identification easier if ever needed.
As you can see, choosing the right cameras and camera placement can be a daunting task. With some planning and familiarization with the aspects of the cameras discussed, you can make intelligent and cost-effective solution decisions, even if you are having a professional perform the installation.
Linda Richardson is director of product marketing for Video Insight, which offers intelligent and user-friendly state-of-the-art IP video surveillance systems, www.video-insight.com.
