Video Surveillance in Schools
The crimes that take place in schools are usually petty crimes, like thefts of clothes or other personal belongings, extortions of small sums of money, bullying of younger students by the older ones. But the number of more serious offenses, including battering and the crimes connected with pushing drugs also becomes a growing problem. Many people understand that even best educative measures cannot solve the problem a complex action is needed. One of efficient methods of improving safety level in a school is CCTV surveillance system, obviously decreasing the number of excesses.The recorded events may often be the only evidence as the witnesses usually don"t want to "testify" against their schoolmates, due to fear of rejection, or in fair for their own safety. Aside from improvement of security, CCTV monitoring helps to protect the school infrastructure and equipment against vandalism, the plague of majority of contemporary schools.
Diagram of surveillance system in a school
The principles
Both education authorities and the firm designing and implementing the project should realize that this kind of extensive building/s with large number of rooms and many appurtenances, as well as financial limitations, will strongly condition the range and precision of the system. First of all - it should ensure general inspection, and only several important locations will be equipped with devices allowing for precise identification of persons.
What to monitor and how?
First of all, there should be observed all possible entries to the school area. The equipment employed in that locations should ensure unambiguous identification of entering persons. The cameras have to be put close to the entrances or be equipped with lenses having large focal length. It will guarantee that the recorded material will give detailed information on appearance of everyone who enters the school, including foreign persons.
Corridors and cloakrooms are the next places where cameras are indispensable. The cameras should be placed as high as possible - it guarantees wide area of observation (without blocking view of one person by another - it is often crowd of people there), and helps to protect the cameras against damaging.
Corridors are often long and narrow - the case requires a number of cameras. They should be arranged the way that each camera sees the next one (e.g. they are placed at two opposite ends of the corridor). It will enable recording of possible attempts of destroying the cameras.
The most arguable issue, whether cameras should be mounted or not, concerns washrooms and toilets. From headmaster"s point of view those rooms are extremely exposed to vandalism and various excesses. They are often considered by students to be smoking rooms.
Taking it into consideration, most of schools mount CCTV monitoring in there. The monitoring provides viewing of the main part of the room, but the inside of the cubicles is excluded from observation. Such monitoring fulfills the task (it is even possible to uncover a smoker, due to soaring smoke) and does not invade privacy of persons. The level of surveillance should be consulted with parents (e.g. acting in parent-teacher association).
In those places there are used smaller dome cameras, e.g. M10744 and M10746 (IR). Similarly popular cameras are models with view angle adjustment - V-CAM 600 M10600
.
Dome cameras M10746 in vandal-proof housings are well prepared for work inside schools
V-CAM 600 M10600 with view angle adjustment
The last area that should also be monitored is surroundings of the school, i.e. playground, sports fields, swimming pool, parking lot, or other places frequented by young people.
Because of limited number of cameras and big monitored area, the role of monitoring is usually to give a general view of the area, without possibility of precise identification. To improve the basic level of usefulness, it is important to employ color system, increasing precision of recognition.
"Secret weapon "- dummy cameras
A vital element of every surveillance system, especially of this kind, is the psychological aspect. The mere thought of being watched makes the people behave correctly, in a cultural way. This fact should be used for "intensification" of visual existence of the system with a number of dummy cameras, mounted in less critical points. This popular method of discouraging potential offenders significantly lowers the cost of the whole installation, but is really effective when the dummies are realistic - the ideal solution requires visually identical items to those being operational.
Choice of cameras - B/W or color
As mentioned, color images ensure much better effects as regards identification of people.
On the other hand, B/W system is more sensitive, and simple to adapt for night observation.
Lower sensitivity of color cameras is usually not a problem for this kind of installations, where the space is illuminated during the night. The second demand, i.e. night observation, possible with B/W cameras due to their spectral-response characteristic and use of IR lamps enabling discreet viewing of dark areas, can also be easily realized with appropriate color cameras.
The suitable color cameras switch at dusk into B/W mode and gain sensitivity. So they may be used for monitoring with IR lighting, like the camera SN-486C, M11202. The cameras are ideal tools for surveillance of playgrounds, sports fields, parking lots etc.
Color day/night camera M11202 is an ideal device for outdoor applications.
Majority of offered cameras is equipped with electronic iris control, changing their sensitivity depending on current lighting conditions. The cameras are capable of working with moderately changing light, e.g. inside a building, with use of cheap lenses without regulated diaphragm. However, cameras operating outside a building should be equipped with lenses with Auto Iris function, allowing to obtain good quality images even in extremely changing lighting conditions, from sun expose to almost complete darkness.
Appearance and mounting of cameras
Due to character of monitored places (with young people having a lot of energy) the cameras may be exposed to accidental or intentional damages. To restrict direct access to a camera, it should be mounted as high as possible, with use of additional housing that will prevent anybody from manipulating the device. There should be employed solid brackets, insensitive to e.g. ball hit. The preferred kind (...)
[This is not complete article. For full version go to DIPOL WLAN, TV-SAT, CCTV web site.]
÷