Video surveillance and recording systems

In addition to the intrusion detection and alert system, the video surveillance system allows the beneficiary to have visual control over protected areas.

A video surveillance system (CCTV - closed circuit television) includes one or more video cameras, an image processing device, a videocassette recorded (VCR - Time Lapse) for recording images on magnetic band (videotape) or a digital video recorder (DVR - standalone model or PC video capture board) for recording images on digital support (HDD, CD, DVD etc.), and a monitor for displaying images.

Performances of a video surveillance and recording system depend on many factors: sensitivity, resolution, position, distance, visibility angle, video camera lens, area and luminosity, details being monitored, surveillance and recording of images etc.

The video surveillance system can be interconnected with an intrusion alert system, access control equipment etc.
The system is made up of the following parts:
• Video camera
Depending on location (indoor or outdoor), quality and clarity of images desired, distance from the place where they are installed to the object under surveillance, area and visibility angle, luminosity and intended purpose, video cameras can be:
- outdoor or indoor;
- black and white or color;
- visible or hidden;
- fixed or mobile (adjustable both horizontally and vertically);
- equipped with fixed iris, manual or auto lens, varifocal, motorized zoom etc.
• Video camera casing
Is used when installing the video camera at the exterior of the objective so as to ensure the best operating conditions and protection against external factors (water, humidity, dust, high or low temperatures etc.). Casings can be equipped with a video camera or lens warming–cooling system.
• Video camera or casing support
Can be fixed (adjustable and positioned to a certain direction) or mobile (equipped with a motor for adjusting the video camera both horizontally and vertically from a command desk).
• Infrared light (IR)
Installed additionally or integrated in the video camera casing for night illumination (in infrared spectrum) of the area under surveillance.
• Video images processing system–video processor (Multiplexor, Switch, Quad)
Processes video images for display in various modes and formats.
Used for displaying a number of video images from video cameras on one monitor only.
Depending on the number of video cameras and the selected image processing system, one or more images can be displayed on the monitor, manually or automatically, at random, programmed, by dividing the screen into 4, 9, 16 or more images etc.
• Video recording system (Videocassette recorder–Time Lapse, Digital Video Recorder)
For storage (recording–viewing) of video images.
The video can be activated manually or automatically (programmed at certain hours or days of the week).
Video images can be processed and recorded in analog or digital format, on magnetic band (videotape) or on digital support (HDD–Hard Disk Drive, CD–Compact Disc, DVD–Digital Versatile Disc etc.).
The Videocassette recording system allows for recording of images on a normal 3–hour videotape for a duration between 3 and 960 hours.
The DVR system may also come equipped with video images processing functions (Multiplexor, Switch, Quad), motion detection activating recording through additional video cameras or motion detectors, remote image transmission (LAN–Internet) etc.
• Video images display device (Monitor)
The monitor is a device used for displaying video images.
Depending on the video images processing device, the screen may display one or more images simultaneously.
Monitors can be black and white or color.

Laws

Video surveillance and recording systems