closed circuit television (CCTV)
CCTV (closed-circuit television) is a TV system in which signals are not publicly distributed but are monitored, primarily for surveillance and security purposes.
CCTV relies on strategic placement of cameras and private observation of the camera's input on monitors. The system is called "closed-circuit" because the cameras, monitors and/or video recorders communicate across a proprietary coaxial cable run or wireless communication link. Access to data transmissions is limited by design.
Older CCTV systems used small, low-resolution black and white monitors with no interactive capabilities. Modern CCTV displays can be high-resolution color, providing the CCTV administrator with the ability to zoom in on an image or track something (or someone). Talk CCTV allows the administrator to speak to people within range of the camera's associated speakers.
CCTV is commonly used for a variety of purposes, including:
- Maintaining perimeter security.
- Monitoring traffic.
- Obtaining a visual record of human activity.
The use of CCTV surveillance in public places has fueled privacy concerns in many parts of the world.
Wikipedia has more information about closed-circuit television.
The Home Office in the U.K. put out this report on the effectiveness of CCTV.
Ron Condon explores the question of whether CCTV systems can stop employee theft.