The Closed Circuit Television surveillance industry has been revolutionised by the comparatively recent adoption of digital technology.This is according to Integrated Surveillance Technologies director Mike Webber who says that the signals produced by digitally-based CCTV systems can easily be routed to any user needing to view them via their organisation’s LAN or WAN.
This is in contrast to the situation in the past with analogue systems which could be viewed at a central point but could not be accessed easily by users in other locations.
Analogue CCTV systems traditionally store video at the rate of about one frame every three seconds meaning that crucial events are often not captured but digital systems are able to capture and store video footage at up to 25 frames per second ensuring that nothing is missed.
The storage of video captured by analogue systems was an administrative nightmare, said Webber, with one video recorder per camera and probably 31 video tapes per recorder being used in rotation
Searching through the tapes was extremely laborious but now, with hard drive-based storage of digital video footage, one video management computer server can store the output from up to 16 fixed cameras and replay any event instantly.
The camera management software allows the user to point moveable dome cameras as well as offering precise control over what video is stored, and for how long. Recording can take place either continuously, on a schedule, as the result of an alarm, or even when the system detects movement.
The software can be set to ignore the movement of a machine or passers-by outside a window but will start the recording when someone enters a room or a designated alarm condition occurs.
Combating crime was the main purpose of analogue CCTV but, said Webber, the high picture quality offered by digital systems has opened up a number of other possible roles for the technology.
IST has installed a number of systems which monitor critical points in production processes and allow executives to view the footage on their desktop computers or even by dialling into the system from a remote location.
Other IST clients are using digital CCTV to record operations which they can refer to in case of a dispute over, for example, what goods were actually loaded onto a truck or who left a door unlocked.
Digital CCTV systems are tailored according to the individuals’ needs and can range in size from a couple of cameras and one server to multi-server configurations with dozens of cameras and many terabytes of storage space in RAID units.