CCTV'S ROLE AND ITS APPLICATIONS
In its broadest sense, the purpose of CCTV in any security-plan is to provide remote eyes for a security operator: to create live-action displays from a distance. The CCTV system should have recording means either a VCR or other storage media to maintain permanent records for training or evidence. Following arc some applications for which CCTV provides an effective solution:
- For security purposes, an overt visual observation of a scene or activity' is required from a remote location.
- An area to be observed contains hazardous material or some action that may kill or injure personnel. Such areas may have toxic chemicals, radioactive material, substances with high potential for fire or explosion, or items that may emit X-ray radiation or other nuclear radiation.
- Visual observation of a scene must be covert. It is much easier to hide a small camera and lens in a concealable location than to station a person in the area.
- There is little activity to watch in an area, as in an intrusion detection location or a storage room, but significant events must be recorded when they occur. Integration of CCTV with alarm sensors and a time-lapse/real-time VCR would provide an extremely powerful solution.
- Many locations must be observed simultaneously by one person from a central security position. For example, tracing a person or vehicle from an entrance into a facility to a final destination, where the person or vehicle will be interdicted by a security' force. Often a guard or security officer must only periodically review a scene for activity. The use of CCTV eliminates the need for a guard to make rounds to remote locations, which would have been wasteful of the guard’s time and unlikely to detect a uespasser.
- When a crime has been committed, it is important to have a hard-copy printout of the activity and event, which requires a television or photographic system. The proliferation of high-quality printed images from VCR equipment has clearly made the case for using CCTV for creating permanent records.
The most effective way to determine that a theft has occurred, when, where, and by whom, is to use CCTV for detection and recording. The particular event can be identified, stored, and later reproduced for display or hard copy. Personnel can be identified on monochrome or color CCTV monitors. Most security installations to date use monochrome CCTV cameras, which provide sufficient information to document the activity and event or identify personnel or articles. Many newer installations use color CCTV, which permits easier identification of personnel or objects.
If there is an emergency or disaster and security personnel must see if personnel arc in a particular area, CCTV can provide ait instantaneous assessment of personnel location and availability.
In many cases during normal operations, CCTV can help ensure the safety of personnel in a facility, determine that personnel have not entered the facility, or confirm that personnel have exited the facility. Such functions arc used, for example where dangerous jobs are performed or hazardous material is handled.
The synergistic combination of audio and CCTV information from a remote site provides an effective source for security. Several camera manufacturers and installers combine video and audio (one way or duplex) using an external microphone or one installed directly into the camera. The video and audio signals are transmitted over the same coaxial, shielded two-wire, or fiber-optic cable, to the security monitoring location, where they are watched live and/or recorded on a VCR. When there is activity in the camera area, the video and audio signals arc switched onto the monitor, the guard secs and hears the scene, and initiates a response.
Most CCTV installations use both overt and covert CCTV cameras, with more cameras overt than covert. Overt installations are designed to deter crime and provide general surveillance of remote areas, such as parking lots, perimeter fence lines, warehouses, entrance lobbies, hallways, or production areas. When CCTV cameras and lenses are exposed, all managers, employees, and visitors realize that the premises are under constant television surveillance. When the need arises, covert installations are used to detect and observe clandestine activity. Although overt video equipment is often large and not meant to be concealed, covert equipment is usually small and designed 10 be hidden in objects in the environment or behind a ceiling or wall. Overt CCTV is often installed permanently, whereas covert CCTV is often designed to be installed quickly, left in place for a few hours, days, or weeks, and then removed. Since minimizing installation time is desirable when installing covert CCTV, video signal transmission often is wireless.
Security Surveillance Applications
CCTV applications fall broadly into two types, indoor and outdoor. This division sets a natural boundary between equipment types: those suitable for controlled indoor environments and those suitable for harsher outdoor environments. The two primary parameters are environmental factors and lighting factors. The indoor system requires artificial lighting, which may or may not be augmented by daylight. The indoor system is subject to only mild indoor temperature and humidity variations, dirt, dust, and smoke. The outdoor system must withstand extreme temperatures, precipitation (fog, rain, snow), wind, dirt, dust, sand, and smoke.
Security Surveillance Applications
CCTV applications fall broadly into two types, indoor and outdoor. This division sets a natural boundary between equipment types: those suitable for controlled indoor environments and those suitable for harsher outdoor environments. The two primary parameters are environmental factors and lighting factors. The indoor system requires artificial lighting, which may or may not be augmented by daylight. The indoor system is subject to only mild indoor temperature and humidity variations, dirt, dust, and smoke. The outdoor system must withstand extreme temperatures, precipitation (fog, rain, snow), wind, dirt, dust, sand, and smoke.
Safety Applications
In public, government, industrial, and other facilities, a safety, security, and personnel protection plan must guard personnel from harm caused by accident, human error, sabotage, or terrorism. Security forces are expected to know the conditions at all locations in the facility through the use of CCTV.
In a hospital room or hallway, the television cameras may serve a dual function: monitoring patients while also determining the status and location of employees, visitors, and others. A guard can watch entrance and exit doors, hallways, operating rooms, drug dispensaries, and other vital areas.
Safety personnel can use CCTV for evacuation and to determine if all personnel have left the area and are safe. Security personnel can use CCTV for remote traffic monitoring and control and to ascertain high-traffic locations and how best to control them. CCTV plays a critical role in public safety, as a tool for monitoring vehicular traffic on highways and city streets, in truck and bus depots, and at public rail and subway facilities and airports.
CCTV Access Control
As security systems become more complex and necessary, CCTV access control and electronic access control equipments are being combined to work synergistically with each other. For medium- to low-level access control security requirements, electronic card reading systems arc adequate after a person has first been identified at some exterior perimeter location. For higher security, biometric descriptors of a person and/or CCTV identification are necessary.
CCTV surveillance is often used with electronic or CCTV access control equipment. CCTV access control uses television to identify remotely a person requesting access, on foot or in a vehicle. A guard can compare the live image and the photo ID carried by the person and then either allow or deny entry. For the highest level of access control security, the guard uses a system to compare the live image to an image of the person retrieved from a video image data bank. The two images are displayed side by side on a split-screen monitor, perhaps along with other pertinent information. At present, different companies manufacture CCTV and electronic access control equipment; there is no single supplier of all the equipment.
The CCTV access control system can be combined with an electronic access control system to increase security and provide a means to track all attempted entries.
This book provides a brief description of CCTV access control equipment and applications. A complete description of specific techniques, equipment, and applications integrating the CCTV access control function with electronic access control is covered in a companion book, CCTV Access Controll.